2110 lines
78 KiB
C++
2110 lines
78 KiB
C++
/* -------------------------------------------------------------------------
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*
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* nbtutils.cpp
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* Utility code for openGauss btree implementation.
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*
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* Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
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* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/gausskernel/storage/access/nbtree/nbtutils.cpp
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*
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* -------------------------------------------------------------------------
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*/
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#include <time.h>
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#include "postgres.h"
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#include "knl/knl_variable.h"
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#include "access/nbtree.h"
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#include "access/reloptions.h"
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#include "access/relscan.h"
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#include "miscadmin.h"
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#include "utils/array.h"
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#include "utils/lsyscache.h"
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#include "utils/memutils.h"
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#include "utils/rel.h"
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#include "utils/rel_gs.h"
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#include "utils/fmgroids.h"
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typedef struct BTSortArrayContext {
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FmgrInfo flinfo;
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Oid collation;
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bool reverse;
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} BTSortArrayContextInfo;
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static Datum _bt_find_extreme_element(IndexScanDesc scan, ScanKey skey, StrategyNumber strat, const Datum *elems,
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int nelems);
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static int _bt_compare_array_elements(const void *a, const void *b, void *arg);
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static bool _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op, ScanKey leftarg, ScanKey rightarg, bool *result);
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static bool _bt_fix_scankey_strategy(ScanKey skey, const int16 *indoption);
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static void _bt_mark_scankey_required(ScanKey skey);
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static int btree_num_keep_atts(Relation rel, IndexTuple lastleft, IndexTuple firstright, BTScanInsert itup_key);
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/*
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* _bt_mkscankey
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* Build an insertion scan key that contains comparison data from itup
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* as well as comparator routines appropriate to the key datatypes.
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*
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* The result is intended for use with _bt_compare().
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*/
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BTScanInsert _bt_mkscankey(Relation rel, IndexTuple itup)
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{
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BTScanInsert key;
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TupleDesc itupdesc;
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int indnatts PG_USED_FOR_ASSERTS_ONLY;
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int indnkeyatts;
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int num_tuple_attrs = itup ? BTREE_TUPLE_GET_NUM_OF_ATTS(itup, rel) : 0;
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int16* indoption = NULL;
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itupdesc = RelationGetDescr(rel);
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indnatts = IndexRelationGetNumberOfAttributes(rel);
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indnkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
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indoption = rel->rd_indoption;
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Assert(indnkeyatts != 0);
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Assert(indnkeyatts <= indnatts);
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Assert(num_tuple_attrs <= indnatts);
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/*
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* We'll execute search using ScanKey constructed on key columns. Non key
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* (included) columns must be omitted.
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*/
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key = (BTScanInsert)palloc(offsetof(BTScanInsertData, scankeys) + indnkeyatts * sizeof(ScanKeyData));
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if (IsSystemRelation(rel) || t_thrd.proc->workingVersionNum < NBTREE_INSERT_OPTIMIZATION_VERSION_NUM) {
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key->heapkeyspace = false;
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key->allequalimage = false;
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} else if (itup) {
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btree_meta_version(rel, &key->heapkeyspace, &key->allequalimage);
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} else {
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key->heapkeyspace = true;
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key->allequalimage = false;
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}
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key->anynullkeys = false; /* initial assumption */
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key->nextkey = false;
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key->pivotsearch = false;
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key->keysz = Min(indnkeyatts, num_tuple_attrs);
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key->scantid = key->heapkeyspace && itup ? btree_tuple_get_heap_tid(itup) : NULL;
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for (int i = 0; i < indnkeyatts; i++) {
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FmgrInfo* procinfo = NULL;
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Datum arg;
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bool null = false;
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uint32 flags;
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/*
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* We can use the cached (default) support procs since no cross-type
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* comparison can be needed.
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*/
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procinfo = index_getprocinfo(rel, i + 1, (uint16)BTORDER_PROC);
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if (i < num_tuple_attrs)
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arg = index_getattr(itup, i + 1, itupdesc, &null);
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else
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{
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arg = (Datum) 0;
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null = true;
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}
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flags = (null ? SK_ISNULL : 0) | (((uint16)indoption[i]) << SK_BT_INDOPTION_SHIFT);
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ScanKeyEntryInitializeWithInfo(&key->scankeys[i], flags, (AttrNumber)(i + 1), InvalidStrategy, InvalidOid,
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rel->rd_indcollation[i], procinfo, arg);
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}
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return key;
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}
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/*
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* _bt_mkscankey_nodata
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* Build an insertion scan key that contains 3-way comparator routines
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* appropriate to the key datatypes, but no comparison data. The
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* comparison data ultimately used must match the key datatypes.
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*
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* The result cannot be used with _bt_compare(), unless comparison
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* data is first stored into the key entries. Currently this
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* routine is only called by nbtsort.c and tuplesort.c, which have
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* their own comparison routines.
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*/
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ScanKey _bt_mkscankey_nodata(Relation rel)
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{
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ScanKey skey;
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int indnkeyatts;
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int16* indoption = NULL;
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int i;
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indnkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
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indoption = rel->rd_indoption;
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skey = (ScanKey) palloc(indnkeyatts * sizeof(ScanKeyData));
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for (i = 0; i < indnkeyatts; i++) {
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FmgrInfo* procinfo = NULL;
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uint32 flags;
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/*
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* We can use the cached (default) support procs since no cross-type
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* comparison can be needed.
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*/
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procinfo = index_getprocinfo(rel, i + 1, (uint16)BTORDER_PROC);
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flags = SK_ISNULL | (((uint16)indoption[i]) << SK_BT_INDOPTION_SHIFT);
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ScanKeyEntryInitializeWithInfo(&skey[i], flags, (AttrNumber)(i + 1), InvalidStrategy, InvalidOid,
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rel->rd_indcollation[i], procinfo, (Datum)0);
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}
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return skey;
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}
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/*
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* free a scan key made by either _bt_mkscankey or _bt_mkscankey_nodata.
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*/
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void _bt_freeskey(ScanKey skey)
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{
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pfree(skey);
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skey = NULL;
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}
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/*
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* free a retracement stack made by _bt_search.
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*/
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void _bt_freestack(BTStack stack)
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{
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BTStack ostack;
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while (stack != NULL) {
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ostack = stack;
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stack = stack->bts_parent;
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pfree(ostack);
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ostack = NULL;
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}
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}
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/*
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* _bt_preprocess_array_keys() -- Preprocess SK_SEARCHARRAY scan keys
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*
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* If there are any SK_SEARCHARRAY scan keys, deconstruct the array(s) and
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* set up BTArrayKeyInfo info for each one that is an equality-type key.
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* Prepare modified scan keys in so->arrayKeyData, which will hold the current
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* array elements during each primitive indexscan operation. For inequality
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* array keys, it's sufficient to find the extreme element value and replace
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* the whole array with that scalar value.
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*
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* Note: the reason we need so->arrayKeyData, rather than just scribbling
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* on scan->keyData, is that callers are permitted to call btrescan without
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* supplying a new set of scankey data.
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*/
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void _bt_preprocess_array_keys(IndexScanDesc scan)
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{
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BTScanOpaque so = (BTScanOpaque)scan->opaque;
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int numberOfKeys = scan->numberOfKeys;
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int16 *indoption = scan->indexRelation->rd_indoption;
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int numArrayKeys;
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ScanKey cur;
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int i;
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MemoryContext oldContext;
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errno_t rc;
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/* Quick check to see if there are any array keys */
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numArrayKeys = 0;
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for (i = 0; i < numberOfKeys; i++) {
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cur = &scan->keyData[i];
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if (cur->sk_flags & SK_SEARCHARRAY) {
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numArrayKeys++;
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Assert(!(cur->sk_flags & (SK_ROW_HEADER | SK_SEARCHNULL | SK_SEARCHNOTNULL)));
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/* If any arrays are null as a whole, we can quit right now. */
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if (cur->sk_flags & SK_ISNULL) {
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so->numArrayKeys = -1;
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so->arrayKeyData = NULL;
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return;
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}
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}
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}
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/* Quit if nothing to do. */
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if (numArrayKeys == 0) {
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so->numArrayKeys = 0;
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so->arrayKeyData = NULL;
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return;
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}
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/*
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* Make a scan-lifespan context to hold array-associated data, or reset it
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* if we already have one from a previous rescan cycle.
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*/
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if (so->arrayContext == NULL) {
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so->arrayContext = AllocSetContextCreate(CurrentMemoryContext, "BTree Array Context", ALLOCSET_SMALL_MINSIZE,
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ALLOCSET_SMALL_INITSIZE, ALLOCSET_SMALL_MAXSIZE);
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} else {
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MemoryContextReset(so->arrayContext);
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}
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oldContext = MemoryContextSwitchTo(so->arrayContext);
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/* Create modifiable copy of scan->keyData in the workspace context */
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so->arrayKeyData = (ScanKey)palloc(scan->numberOfKeys * sizeof(ScanKeyData));
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rc = memcpy_s(so->arrayKeyData, scan->numberOfKeys * sizeof(ScanKeyData), scan->keyData,
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scan->numberOfKeys * sizeof(ScanKeyData));
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securec_check(rc, "", "");
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/* Allocate space for per-array data in the workspace context */
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so->arrayKeys = (BTArrayKeyInfo *)palloc0(numArrayKeys * sizeof(BTArrayKeyInfo));
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/* Now process each array key */
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numArrayKeys = 0;
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for (i = 0; i < numberOfKeys; i++) {
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ArrayType *arrayval = NULL;
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int16 elmlen;
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bool elmbyval = false;
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char elmalign;
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int num_elems;
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Datum *elem_values = NULL;
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bool *elem_nulls = NULL;
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int num_nonnulls;
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int j;
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cur = &so->arrayKeyData[i];
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if (!(cur->sk_flags & SK_SEARCHARRAY)) {
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continue;
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}
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/*
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* First, deconstruct the array into elements. Anything allocated
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* here (including a possibly detoasted array value) is in the
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* workspace context.
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*/
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arrayval = DatumGetArrayTypeP(cur->sk_argument);
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/* We could cache this data, but not clear it's worth it */
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get_typlenbyvalalign(ARR_ELEMTYPE(arrayval), &elmlen, &elmbyval, &elmalign);
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deconstruct_array(arrayval, ARR_ELEMTYPE(arrayval), elmlen, elmbyval, elmalign, &elem_values, &elem_nulls,
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&num_elems);
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/*
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* Compress out any null elements. We can ignore them since we assume
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* all btree operators are strict.
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*/
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num_nonnulls = 0;
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for (j = 0; j < num_elems; j++) {
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if (!elem_nulls[j]) {
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elem_values[num_nonnulls++] = elem_values[j];
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}
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}
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/* We could pfree(elem_nulls) now, but not worth the cycles
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* If there's no non-nulls, the scan qual is unsatisfiable
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*/
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if (num_nonnulls == 0) {
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numArrayKeys = -1;
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break;
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}
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/*
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* If the comparison operator is not equality, then the array qual
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* degenerates to a simple comparison against the smallest or largest
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* non-null array element, as appropriate.
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*/
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switch (cur->sk_strategy) {
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case BTLessStrategyNumber:
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case BTLessEqualStrategyNumber:
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cur->sk_argument = _bt_find_extreme_element(scan, cur, BTGreaterStrategyNumber, elem_values,
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num_nonnulls);
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continue;
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case BTEqualStrategyNumber:
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/* proceed with rest of loop */
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break;
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case BTGreaterEqualStrategyNumber:
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case BTGreaterStrategyNumber:
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cur->sk_argument = _bt_find_extreme_element(scan, cur, BTLessStrategyNumber, elem_values, num_nonnulls);
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continue;
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default:
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("unrecognized StrategyNumber: %d", (int)cur->sk_strategy)));
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break;
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}
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/*
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* Sort the non-null elements and eliminate any duplicates. We must
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* sort in the same ordering used by the index column, so that the
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* successive primitive indexscans produce data in index order.
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*/
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num_elems = _bt_sort_array_elements(scan, cur, (indoption[cur->sk_attno - 1] & INDOPTION_DESC) != 0,
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elem_values, num_nonnulls);
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/*
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* And set up the BTArrayKeyInfo data.
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*/
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so->arrayKeys[numArrayKeys].scan_key = i;
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so->arrayKeys[numArrayKeys].num_elems = num_elems;
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so->arrayKeys[numArrayKeys].elem_values = elem_values;
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numArrayKeys++;
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}
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so->numArrayKeys = numArrayKeys;
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MemoryContextSwitchTo(oldContext);
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}
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/*
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* _bt_find_extreme_element() -- get least or greatest array element
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*
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* scan and skey identify the index column, whose opfamily determines the
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* comparison semantics. strat should be BTLessStrategyNumber to get the
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* least element, or BTGreaterStrategyNumber to get the greatest.
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*/
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static Datum _bt_find_extreme_element(IndexScanDesc scan, const ScanKey skey, StrategyNumber strat, const Datum *elems,
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int nelems)
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{
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Relation rel = scan->indexRelation;
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Oid elemtype, cmp_op;
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RegProcedure cmp_proc;
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FmgrInfo flinfo;
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Datum result;
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int i;
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/*
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* Determine the nominal datatype of the array elements. We have to
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* support the convention that sk_subtype == InvalidOid means the opclass
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* input type; this is a hack to simplify life for ScanKeyInit().
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*/
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elemtype = skey->sk_subtype;
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if (elemtype == InvalidOid) {
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elemtype = rel->rd_opcintype[skey->sk_attno - 1];
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}
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/*
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* Look up the appropriate comparison operator in the opfamily.
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*
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* Note: it's possible that this would fail, if the opfamily is
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* incomplete, but it seems quite unlikely that an opfamily would omit
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* non-cross-type comparison operators for any datatype that it supports
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* at all.
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*/
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cmp_op = get_opfamily_member(rel->rd_opfamily[skey->sk_attno - 1], elemtype, elemtype, strat);
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if (!OidIsValid(cmp_op)) {
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ereport(ERROR,
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(errcode(ERRCODE_SYNTAX_ERROR), errmsg("missing operator %d(%u,%u) in opfamily %u", strat, elemtype,
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elemtype, rel->rd_opfamily[skey->sk_attno - 1])));
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}
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cmp_proc = get_opcode(cmp_op);
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if (!RegProcedureIsValid(cmp_proc)) {
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ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("missing oprcode for operator %u", cmp_op)));
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}
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fmgr_info(cmp_proc, &flinfo);
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Assert(nelems > 0);
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result = elems[0];
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for (i = 1; i < nelems; i++) {
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if (DatumGetBool(FunctionCall2Coll(&flinfo, skey->sk_collation, elems[i], result))) {
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result = elems[i];
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}
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}
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return result;
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}
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/*
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* _bt_sort_array_elements() -- sort and de-dup array elements
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*
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* The array elements are sorted in-place, and the new number of elements
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* after duplicate removal is returned.
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*
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* scan and skey identify the index column, whose opfamily determines the
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* comparison semantics. If reverse is true, we sort in descending order.
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*/
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int _bt_sort_array_elements(IndexScanDesc scan, const ScanKey skey, bool reverse, Datum *elems, int nelems)
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{
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Relation rel = scan->indexRelation;
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Oid elemtype;
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RegProcedure cmp_proc;
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BTSortArrayContext cxt = {0};
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int last_non_dup;
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int i;
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if (nelems <= 1) {
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return nelems; /* no work to do */
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}
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/*
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* Determine the nominal datatype of the array elements. We have to
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* support the convention that sk_subtype == InvalidOid means the opclass
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* input type; this is a hack to simplify life for ScanKeyInit().
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*/
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elemtype = skey->sk_subtype;
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if (elemtype == InvalidOid) {
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elemtype = rel->rd_opcintype[skey->sk_attno - 1];
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}
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/*
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* Look up the appropriate comparison function in the opfamily.
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*
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* Note: it's possible that this would fail, if the opfamily is
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* incomplete, but it seems quite unlikely that an opfamily would omit
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* non-cross-type support functions for any datatype that it supports at
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* all.
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*/
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cmp_proc = get_opfamily_proc(rel->rd_opfamily[skey->sk_attno - 1], elemtype, elemtype, BTORDER_PROC);
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if (!RegProcedureIsValid(cmp_proc)) {
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ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
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errmsg("missing support function %d(%u,%u) in opfamily %u", BTORDER_PROC, elemtype, elemtype,
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rel->rd_opfamily[skey->sk_attno - 1])));
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}
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/* Sort the array elements */
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fmgr_info(cmp_proc, &cxt.flinfo);
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cxt.collation = skey->sk_collation;
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cxt.reverse = reverse;
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qsort_arg((void *)elems, (size_t)nelems, sizeof(Datum), _bt_compare_array_elements, (void *)&cxt);
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/* Now scan the sorted elements and remove duplicates */
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last_non_dup = 0;
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for (i = 1; i < nelems; i++) {
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int32 compare;
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compare = DatumGetInt32(FunctionCall2Coll(&cxt.flinfo, cxt.collation, elems[last_non_dup], elems[i]));
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if (compare != 0) {
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elems[++last_non_dup] = elems[i];
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}
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}
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return last_non_dup + 1;
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}
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/*
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* qsort_arg comparator for sorting array elements
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*/
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static int _bt_compare_array_elements(const void *a, const void *b, void *arg)
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{
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Datum da = *((const Datum *)a);
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Datum db = *((const Datum *)b);
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BTSortArrayContext *cxt = (BTSortArrayContext *)arg;
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int32 compare;
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compare = DatumGetInt32(FunctionCall2Coll(&cxt->flinfo, cxt->collation, da, db));
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if (cxt->reverse) {
|
|
compare = -compare;
|
|
}
|
|
return compare;
|
|
}
|
|
|
|
/*
|
|
* _bt_start_array_keys() -- Initialize array keys at start of a scan
|
|
*
|
|
* Set up the cur_elem counters and fill in the first sk_argument value for
|
|
* each array scankey. We can't do this until we know the scan direction.
|
|
*/
|
|
void _bt_start_array_keys(IndexScanDesc scan, ScanDirection dir)
|
|
{
|
|
BTScanOpaque so = (BTScanOpaque)scan->opaque;
|
|
for (int i = 0; i < so->numArrayKeys; i++) {
|
|
BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
|
|
ScanKey skey = &so->arrayKeyData[curArrayKey->scan_key];
|
|
|
|
Assert(curArrayKey->num_elems > 0);
|
|
if (ScanDirectionIsBackward(dir)) {
|
|
curArrayKey->cur_elem = curArrayKey->num_elems - 1;
|
|
} else {
|
|
curArrayKey->cur_elem = 0;
|
|
}
|
|
skey->sk_argument = curArrayKey->elem_values[curArrayKey->cur_elem];
|
|
}
|
|
}
|
|
|
|
/*
|
|
* _bt_advance_array_keys() -- Advance to next set of array elements
|
|
*
|
|
* Returns TRUE if there is another set of values to consider, FALSE if not.
|
|
* On TRUE result, the scankeys are initialized with the next set of values.
|
|
*/
|
|
bool _bt_advance_array_keys(IndexScanDesc scan, ScanDirection dir)
|
|
{
|
|
BTScanOpaque so = (BTScanOpaque)scan->opaque;
|
|
bool found = false;
|
|
int i;
|
|
|
|
/*
|
|
* We must advance the last array key most quickly, since it will
|
|
* correspond to the lowest-order index column among the available
|
|
* qualifications. This is necessary to ensure correct ordering of output
|
|
* when there are multiple array keys.
|
|
*/
|
|
for (i = so->numArrayKeys - 1; i >= 0; i--) {
|
|
BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
|
|
ScanKey skey = &so->arrayKeyData[curArrayKey->scan_key];
|
|
int cur_elem = curArrayKey->cur_elem;
|
|
int num_elems = curArrayKey->num_elems;
|
|
|
|
if (ScanDirectionIsBackward(dir)) {
|
|
if (--cur_elem < 0) {
|
|
cur_elem = num_elems - 1;
|
|
found = false; /* need to advance next array key */
|
|
} else {
|
|
found = true;
|
|
}
|
|
} else {
|
|
if (++cur_elem >= num_elems) {
|
|
cur_elem = 0;
|
|
found = false; /* need to advance next array key */
|
|
} else {
|
|
found = true;
|
|
}
|
|
}
|
|
|
|
curArrayKey->cur_elem = cur_elem;
|
|
skey->sk_argument = curArrayKey->elem_values[cur_elem];
|
|
if (found) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* _bt_mark_array_keys() -- Handle array keys during btmarkpos
|
|
*
|
|
* Save the current state of the array keys as the "mark" position.
|
|
*/
|
|
void _bt_mark_array_keys(IndexScanDesc scan)
|
|
{
|
|
BTScanOpaque so = (BTScanOpaque)scan->opaque;
|
|
int i;
|
|
|
|
for (i = 0; i < so->numArrayKeys; i++) {
|
|
BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
|
|
curArrayKey->mark_elem = curArrayKey->cur_elem;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* _bt_restore_array_keys() -- Handle array keys during btrestrpos
|
|
*
|
|
* Restore the array keys to where they were when the mark was set.
|
|
*/
|
|
void _bt_restore_array_keys(IndexScanDesc scan)
|
|
{
|
|
BTScanOpaque so = (BTScanOpaque)scan->opaque;
|
|
bool changed = false;
|
|
int i;
|
|
|
|
/* Restore each array key to its position when the mark was set */
|
|
for (i = 0; i < so->numArrayKeys; i++) {
|
|
BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
|
|
ScanKey skey = &so->arrayKeyData[curArrayKey->scan_key];
|
|
int mark_elem = curArrayKey->mark_elem;
|
|
if (curArrayKey->cur_elem != mark_elem) {
|
|
curArrayKey->cur_elem = mark_elem;
|
|
skey->sk_argument = curArrayKey->elem_values[mark_elem];
|
|
changed = true;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we changed any keys, we must redo _bt_preprocess_keys. That might
|
|
* sound like overkill, but in cases with multiple keys per index column
|
|
* it seems necessary to do the full set of pushups.
|
|
*/
|
|
if (changed) {
|
|
_bt_preprocess_keys(scan);
|
|
/* The mark should have been set on a consistent set of keys... */
|
|
Assert(so->qual_ok);
|
|
}
|
|
}
|
|
|
|
/* use to reduce the number of memset operations */
|
|
#define RESET_STRATEGY_KEYS(xform) do { \
|
|
xform[0] = NULL; \
|
|
xform[1] = NULL; \
|
|
xform[2] = NULL; \
|
|
xform[3] = NULL; \
|
|
xform[4] = NULL; \
|
|
} while (0)
|
|
|
|
/*
|
|
* _bt_preprocess_keys() -- Preprocess scan keys
|
|
*
|
|
* The given search-type keys (in scan->keyData[] or so->arrayKeyData[])
|
|
* are copied to so->keyData[] with possible transformation.
|
|
* scan->numberOfKeys is the number of input keys, so->numberOfKeys gets
|
|
* the number of output keys (possibly less, never greater).
|
|
*
|
|
* The output keys are marked with additional sk_flag bits beyond the
|
|
* system-standard bits supplied by the caller. The DESC and NULLS_FIRST
|
|
* indoption bits for the relevant index attribute are copied into the flags.
|
|
* Also, for a DESC column, we commute (flip) all the sk_strategy numbers
|
|
* so that the index sorts in the desired direction.
|
|
*
|
|
* One key purpose of this routine is to discover which scan keys must be
|
|
* satisfied to continue the scan. It also attempts to eliminate redundant
|
|
* keys and detect contradictory keys. (If the index opfamily provides
|
|
* incomplete sets of cross-type operators, we may fail to detect redundant
|
|
* or contradictory keys, but we can survive that.)
|
|
*
|
|
* The output keys must be sorted by index attribute. Presently we expect
|
|
* (but verify) that the input keys are already so sorted --- this is done
|
|
* by match_clauses_to_index() in indxpath.c. Some reordering of the keys
|
|
* within each attribute may be done as a byproduct of the processing here,
|
|
* but no other code depends on that.
|
|
*
|
|
* The output keys are marked with flags SK_BT_REQFWD and/or SK_BT_REQBKWD
|
|
* if they must be satisfied in order to continue the scan forward or backward
|
|
* respectively. _bt_checkkeys uses these flags. For example, if the quals
|
|
* are "x = 1 AND y < 4 AND z < 5", then _bt_checkkeys will reject a tuple
|
|
* (1,2,7), but we must continue the scan in case there are tuples (1,3,z).
|
|
* But once we reach tuples like (1,4,z) we can stop scanning because no
|
|
* later tuples could match. This is reflected by marking the x and y keys,
|
|
* but not the z key, with SK_BT_REQFWD. In general, the keys for leading
|
|
* attributes with "=" keys are marked both SK_BT_REQFWD and SK_BT_REQBKWD.
|
|
* For the first attribute without an "=" key, any "<" and "<=" keys are
|
|
* marked SK_BT_REQFWD while any ">" and ">=" keys are marked SK_BT_REQBKWD.
|
|
* This can be seen to be correct by considering the above example. Note
|
|
* in particular that if there are no keys for a given attribute, the keys for
|
|
* subsequent attributes can never be required; for instance "WHERE y = 4"
|
|
* requires a full-index scan.
|
|
*
|
|
* If possible, redundant keys are eliminated: we keep only the tightest
|
|
* >/>= bound and the tightest </<= bound, and if there's an = key then
|
|
* that's the only one returned. (So, we return either a single = key,
|
|
* or one or two boundary-condition keys for each attr.) However, if we
|
|
* cannot compare two keys for lack of a suitable cross-type operator,
|
|
* we cannot eliminate either. If there are two such keys of the same
|
|
* operator strategy, the second one is just pushed into the output array
|
|
* without further processing here. We may also emit both >/>= or both
|
|
* </<= keys if we can't compare them. The logic about required keys still
|
|
* works if we don't eliminate redundant keys.
|
|
*
|
|
* Note that one reason we need direction-sensitive required-key flags is
|
|
* precisely that we may not be able to eliminate redundant keys. Suppose
|
|
* we have "x > 4::int AND x > 10::bigint", and we are unable to determine
|
|
* which key is more restrictive for lack of a suitable cross-type operator.
|
|
* _bt_first will arbitrarily pick one of the keys to do the initial
|
|
* positioning with. If it picks x > 4, then the x > 10 condition will fail
|
|
* until we reach index entries > 10; but we can't stop the scan just because
|
|
* x > 10 is failing. On the other hand, if we are scanning backwards, then
|
|
* failure of either key is indeed enough to stop the scan. (In general, when
|
|
* inequality keys are present, the initial-positioning code only promises to
|
|
* position before the first possible match, not exactly at the first match,
|
|
* for a forward scan; or after the last match for a backward scan.)
|
|
*
|
|
* As a byproduct of this work, we can detect contradictory quals such
|
|
* as "x = 1 AND x > 2". If we see that, we return so->qual_ok = FALSE,
|
|
* indicating the scan need not be run at all since no tuples can match.
|
|
* (In this case we do not bother completing the output key array!)
|
|
* Again, missing cross-type operators might cause us to fail to prove the
|
|
* quals contradictory when they really are, but the scan will work correctly.
|
|
*
|
|
* Row comparison keys are currently also treated without any smarts:
|
|
* we just transfer them into the preprocessed array without any
|
|
* editorialization. We can treat them the same as an ordinary inequality
|
|
* comparison on the row's first index column, for the purposes of the logic
|
|
* about required keys.
|
|
*
|
|
* Note: the reason we have to copy the preprocessed scan keys into private
|
|
* storage is that we are modifying the array based on comparisons of the
|
|
* key argument values, which could change on a rescan or after moving to
|
|
* new elements of array keys. Therefore we can't overwrite the source data.
|
|
*/
|
|
void _bt_preprocess_keys(IndexScanDesc scan)
|
|
{
|
|
BTScanOpaque so = (BTScanOpaque)scan->opaque;
|
|
int numberOfKeys = scan->numberOfKeys;
|
|
int16 *indoption = scan->indexRelation->rd_indoption;
|
|
int new_numberOfKeys;
|
|
int numberOfEqualCols;
|
|
ScanKey inkeys;
|
|
ScanKey outkeys;
|
|
ScanKey cur;
|
|
bool test_result = false;
|
|
int i, j;
|
|
AttrNumber attno;
|
|
|
|
/* initialize result variables */
|
|
so->qual_ok = true;
|
|
so->numberOfKeys = 0;
|
|
|
|
if (numberOfKeys < 1) {
|
|
return; /* done if qual-less scan */
|
|
}
|
|
|
|
/* Read so->arrayKeyData if array keys are present, else scan->keyData */
|
|
inkeys = (so->arrayKeyData != NULL) ? so->arrayKeyData : scan->keyData;
|
|
|
|
outkeys = so->keyData;
|
|
cur = &inkeys[0];
|
|
/* we check that input keys are correctly ordered */
|
|
if (SECUREC_UNLIKELY(cur->sk_attno < 1)){
|
|
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("btree index keys must be ordered by attribute")));
|
|
}
|
|
|
|
/* We can short-circuit most of the work if there's just one key */
|
|
if (numberOfKeys == 1) {
|
|
/* Apply indoption to scankey (might change sk_strategy!) */
|
|
if (!_bt_fix_scankey_strategy(cur, indoption)) {
|
|
so->qual_ok = false;
|
|
}
|
|
*outkeys = *cur;
|
|
so->numberOfKeys = 1;
|
|
/* We can mark the qual as required if it's for first index col */
|
|
if (cur->sk_attno == 1) {
|
|
_bt_mark_scankey_required(outkeys);
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* Otherwise, do the full set of pushups. */
|
|
ScanKey xform[BTMaxStrategyNumber];
|
|
RESET_STRATEGY_KEYS(xform);
|
|
new_numberOfKeys = 0;
|
|
numberOfEqualCols = 0;
|
|
|
|
/*
|
|
* Initialize for processing of keys for attr 1.
|
|
*
|
|
* xform[i] points to the currently best scan key of strategy type i+1; it
|
|
* is NULL if we haven't yet found such a key for this attr.
|
|
*/
|
|
attno = 1;
|
|
|
|
/*
|
|
* Loop iterates from 0 to numberOfKeys inclusive; we use the last pass to
|
|
* handle after-last-key processing. Actual exit from the loop is at the
|
|
* "break" statement below.
|
|
*/
|
|
for (i = 0;; cur++, i++) {
|
|
if (i < numberOfKeys) {
|
|
/* Apply indoption to scankey (might change sk_strategy!) */
|
|
if (!_bt_fix_scankey_strategy(cur, indoption)) {
|
|
/* NULL can't be matched, so give up */
|
|
so->qual_ok = false;
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we are at the end of the keys for a particular attr, finish up
|
|
* processing and emit the cleaned-up keys.
|
|
*/
|
|
if (i == numberOfKeys || cur->sk_attno != attno) {
|
|
int priorNumberOfEqualCols = numberOfEqualCols;
|
|
|
|
/* check input keys are correctly ordered */
|
|
if (SECUREC_UNLIKELY(i < numberOfKeys && cur->sk_attno < attno)) {
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SYNTAX_ERROR), errmsg("btree index keys must be ordered by attribute")));
|
|
}
|
|
|
|
/*
|
|
* If = has been specified, all other keys can be eliminated as
|
|
* redundant. If we have a case like key = 1 AND key > 2, we can
|
|
* set qual_ok to false and abandon further processing.
|
|
*
|
|
* We also have to deal with the case of "key IS NULL", which is
|
|
* unsatisfiable in combination with any other index condition. By
|
|
* the time we get here, that's been classified as an equality
|
|
* check, and we've rejected any combination of it with a regular
|
|
* equality condition; but not with other types of conditions.
|
|
*/
|
|
if (xform[BTEqualStrategyNumber - 1]) {
|
|
ScanKey eq = xform[BTEqualStrategyNumber - 1];
|
|
|
|
for (j = BTMaxStrategyNumber; --j >= 0;) {
|
|
ScanKey chk = xform[j];
|
|
|
|
if (!chk || j == (BTEqualStrategyNumber - 1)) {
|
|
continue;
|
|
}
|
|
|
|
if (eq->sk_flags & SK_SEARCHNULL) {
|
|
/* IS NULL is contradictory to anything else */
|
|
so->qual_ok = false;
|
|
return;
|
|
}
|
|
|
|
if (_bt_compare_scankey_args(scan, chk, eq, chk, &test_result)) {
|
|
if (!test_result) {
|
|
/* keys proven mutually contradictory */
|
|
so->qual_ok = false;
|
|
return;
|
|
}
|
|
/* else discard the redundant non-equality key */
|
|
xform[j] = NULL;
|
|
}
|
|
/* else, cannot determine redundancy, keep both keys */
|
|
}
|
|
/* track number of attrs for which we have "=" keys */
|
|
numberOfEqualCols++;
|
|
}
|
|
|
|
/* try to keep only one of <, <= */
|
|
if (xform[BTLessStrategyNumber - 1] && xform[BTLessEqualStrategyNumber - 1]) {
|
|
ScanKey lt = xform[BTLessStrategyNumber - 1];
|
|
ScanKey le = xform[BTLessEqualStrategyNumber - 1];
|
|
|
|
if (_bt_compare_scankey_args(scan, le, lt, le, &test_result)) {
|
|
if (test_result) {
|
|
xform[BTLessEqualStrategyNumber - 1] = NULL;
|
|
} else {
|
|
xform[BTLessStrategyNumber - 1] = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* try to keep only one of >, >= */
|
|
if (xform[BTGreaterStrategyNumber - 1] && xform[BTGreaterEqualStrategyNumber - 1]) {
|
|
ScanKey gt = xform[BTGreaterStrategyNumber - 1];
|
|
ScanKey ge = xform[BTGreaterEqualStrategyNumber - 1];
|
|
|
|
if (_bt_compare_scankey_args(scan, ge, gt, ge, &test_result)) {
|
|
if (test_result) {
|
|
xform[BTGreaterEqualStrategyNumber - 1] = NULL;
|
|
} else {
|
|
xform[BTGreaterStrategyNumber - 1] = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Emit the cleaned-up keys into the outkeys[] array, and then
|
|
* mark them if they are required. They are required (possibly
|
|
* only in one direction) if all attrs before this one had "=".
|
|
*/
|
|
for (j = BTMaxStrategyNumber; --j >= 0;) {
|
|
if (xform[j]) {
|
|
ScanKey outkey = &outkeys[new_numberOfKeys++];
|
|
*outkey = *xform[j];
|
|
if (priorNumberOfEqualCols == attno - 1) {
|
|
_bt_mark_scankey_required(outkey);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Exit loop here if done. */
|
|
if (i == numberOfKeys) {
|
|
break;
|
|
}
|
|
|
|
/* Re-initialize for new attno */
|
|
attno = cur->sk_attno;
|
|
RESET_STRATEGY_KEYS(xform);
|
|
}
|
|
|
|
/* check strategy this key's operator corresponds to */
|
|
j = cur->sk_strategy - 1;
|
|
|
|
/* if row comparison, push it directly to the output array */
|
|
if (cur->sk_flags & SK_ROW_HEADER) {
|
|
ScanKey outkey = &outkeys[new_numberOfKeys++];
|
|
*outkey = *cur;
|
|
if (numberOfEqualCols == attno - 1) {
|
|
_bt_mark_scankey_required(outkey);
|
|
}
|
|
|
|
/* We don't support RowCompare using equality; such a qual would
|
|
* mess up the numberOfEqualCols tracking. */
|
|
Assert(j != (BTEqualStrategyNumber - 1));
|
|
continue;
|
|
}
|
|
|
|
/* have we seen one of these before? */
|
|
if (xform[j] == NULL) {
|
|
/* nope, so remember this scankey */
|
|
xform[j] = cur;
|
|
} else {
|
|
/* yup, keep only the more restrictive key */
|
|
if (_bt_compare_scankey_args(scan, cur, cur, xform[j], &test_result)) {
|
|
if (test_result) {
|
|
xform[j] = cur;
|
|
} else if (j == (BTEqualStrategyNumber - 1)) {
|
|
/* key == a && key == b, but a != b */
|
|
so->qual_ok = false;
|
|
return;
|
|
}
|
|
/* else old key is more restrictive, keep it */
|
|
} else {
|
|
/*
|
|
* We can't determine which key is more restrictive. Keep the
|
|
* previous one in xform[j] and push this one directly to the
|
|
* output array.
|
|
*/
|
|
ScanKey outkey = &outkeys[new_numberOfKeys++];
|
|
*outkey = *cur;
|
|
if (numberOfEqualCols == attno - 1) {
|
|
_bt_mark_scankey_required(outkey);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
so->numberOfKeys = new_numberOfKeys;
|
|
}
|
|
|
|
/*
|
|
* Compare two scankey values using a specified operator.
|
|
*
|
|
* The test we want to perform is logically "leftarg op rightarg", where
|
|
* leftarg and rightarg are the sk_argument values in those ScanKeys, and
|
|
* the comparison operator is the one in the op ScanKey. However, in
|
|
* cross-data-type situations we may need to look up the correct operator in
|
|
* the index's opfamily: it is the one having amopstrategy = op->sk_strategy
|
|
* and amoplefttype/amoprighttype equal to the two argument datatypes.
|
|
*
|
|
* If the opfamily doesn't supply a complete set of cross-type operators we
|
|
* may not be able to make the comparison. If we can make the comparison
|
|
* we store the operator result in *result and return TRUE. We return FALSE
|
|
* if the comparison could not be made.
|
|
*
|
|
* Note: op always points at the same ScanKey as either leftarg or rightarg.
|
|
* Since we don't scribble on the scankeys, this aliasing should cause no
|
|
* trouble.
|
|
*
|
|
* Note: this routine needs to be insensitive to any DESC option applied
|
|
* to the index column. For example, "x < 4" is a tighter constraint than
|
|
* "x < 5" regardless of which way the index is sorted.
|
|
*/
|
|
static bool _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op, const ScanKey leftarg, const ScanKey rightarg,
|
|
bool *result)
|
|
{
|
|
Relation rel = scan->indexRelation;
|
|
Oid lefttype, righttype, optype, opcintype, cmp_op;
|
|
StrategyNumber strat;
|
|
|
|
/*
|
|
* First, deal with cases where one or both args are NULL. This should
|
|
* only happen when the scankeys represent IS NULL/NOT NULL conditions.
|
|
*/
|
|
if ((leftarg->sk_flags | rightarg->sk_flags) & SK_ISNULL) {
|
|
int leftnull;
|
|
int rightnull;
|
|
|
|
if (leftarg->sk_flags & SK_ISNULL) {
|
|
Assert(leftarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
|
|
leftnull = 1;
|
|
} else {
|
|
leftnull = 0;
|
|
}
|
|
if (rightarg->sk_flags & SK_ISNULL) {
|
|
Assert(rightarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
|
|
rightnull = 1;
|
|
} else {
|
|
rightnull = 0;
|
|
}
|
|
|
|
/*
|
|
* We treat NULL as either greater than or less than all other values.
|
|
* Since true > false, the tests below work correctly for NULLS LAST
|
|
* logic. If the index is NULLS FIRST, we need to flip the strategy.
|
|
*/
|
|
strat = op->sk_strategy;
|
|
if (op->sk_flags & SK_BT_NULLS_FIRST) {
|
|
strat = (uint16)BTCommuteStrategyNumber(strat);
|
|
}
|
|
|
|
switch (strat) {
|
|
case BTLessStrategyNumber:
|
|
*result = (leftnull < rightnull);
|
|
break;
|
|
case BTLessEqualStrategyNumber:
|
|
*result = (leftnull <= rightnull);
|
|
break;
|
|
case BTEqualStrategyNumber:
|
|
*result = (leftnull == rightnull);
|
|
break;
|
|
case BTGreaterEqualStrategyNumber:
|
|
*result = (leftnull >= rightnull);
|
|
break;
|
|
case BTGreaterStrategyNumber:
|
|
*result = (leftnull > rightnull);
|
|
break;
|
|
default: {
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INDEX_CORRUPTED), errmsg("unrecognized StrategyNumber: %d", (int)strat)));
|
|
*result = false; /* keep compiler quiet */
|
|
break;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* The opfamily we need to worry about is identified by the index column. */
|
|
Assert(leftarg->sk_attno == rightarg->sk_attno);
|
|
opcintype = rel->rd_opcintype[leftarg->sk_attno - 1];
|
|
|
|
/*
|
|
* Determine the actual datatypes of the ScanKey arguments. We have to
|
|
* support the convention that sk_subtype == InvalidOid means the opclass
|
|
* input type; this is a hack to simplify life for ScanKeyInit().
|
|
*/
|
|
lefttype = leftarg->sk_subtype;
|
|
if (lefttype == InvalidOid) {
|
|
lefttype = opcintype;
|
|
}
|
|
righttype = rightarg->sk_subtype;
|
|
if (righttype == InvalidOid) {
|
|
righttype = opcintype;
|
|
}
|
|
optype = op->sk_subtype;
|
|
if (optype == InvalidOid) {
|
|
optype = opcintype;
|
|
}
|
|
|
|
/*
|
|
* If leftarg and rightarg match the types expected for the "op" scankey,
|
|
* we can use its already-looked-up comparison function.
|
|
*/
|
|
if (lefttype == opcintype && righttype == optype) {
|
|
*result = DatumGetBool(
|
|
FunctionCall2Coll(&op->sk_func, op->sk_collation, leftarg->sk_argument, rightarg->sk_argument));
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Otherwise, we need to go to the syscache to find the appropriate
|
|
* operator. (This cannot result in infinite recursion, since no
|
|
* indexscan initiated by syscache lookup will use cross-data-type
|
|
* operators.)
|
|
*
|
|
* If the sk_strategy was flipped by _bt_fix_scankey_strategy, we have to
|
|
* un-flip it to get the correct opfamily member.
|
|
*/
|
|
strat = op->sk_strategy;
|
|
if (op->sk_flags & SK_BT_DESC) {
|
|
strat = (uint16)BTCommuteStrategyNumber(strat);
|
|
}
|
|
|
|
cmp_op = get_opfamily_member(rel->rd_opfamily[leftarg->sk_attno - 1], lefttype, righttype, strat);
|
|
if (OidIsValid(cmp_op)) {
|
|
RegProcedure cmp_proc = get_opcode(cmp_op);
|
|
if (RegProcedureIsValid(cmp_proc)) {
|
|
*result = DatumGetBool(
|
|
OidFunctionCall2Coll(cmp_proc, op->sk_collation, leftarg->sk_argument, rightarg->sk_argument));
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/* Can't make the comparison */
|
|
*result = false; /* suppress compiler warnings */
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Adjust a scankey's strategy and flags setting as needed for indoptions.
|
|
*
|
|
* We copy the appropriate indoption value into the scankey sk_flags
|
|
* (shifting to avoid clobbering system-defined flag bits). Also, if
|
|
* the DESC option is set, commute (flip) the operator strategy number.
|
|
*
|
|
* A secondary purpose is to check for IS NULL/NOT NULL scankeys and set up
|
|
* the strategy field correctly for them.
|
|
*
|
|
* Lastly, for ordinary scankeys (not IS NULL/NOT NULL), we check for a
|
|
* NULL comparison value. Since all btree operators are assumed strict,
|
|
* a NULL means that the qual cannot be satisfied. We return TRUE if the
|
|
* comparison value isn't NULL, or FALSE if the scan should be abandoned.
|
|
*
|
|
* This function is applied to the *input* scankey structure; therefore
|
|
* on a rescan we will be looking at already-processed scankeys. Hence
|
|
* we have to be careful not to re-commute the strategy if we already did it.
|
|
* It's a bit ugly to modify the caller's copy of the scankey but in practice
|
|
* there shouldn't be any problem, since the index's indoptions are certainly
|
|
* not going to change while the scankey survives.
|
|
*/
|
|
static bool _bt_fix_scankey_strategy(ScanKey skey, const int16 *indoption)
|
|
{
|
|
int addflags;
|
|
addflags = (uint16)(indoption[skey->sk_attno - 1]) << SK_BT_INDOPTION_SHIFT;
|
|
|
|
/*
|
|
* We treat all btree operators as strict (even if they're not so marked
|
|
* in pg_proc). This means that it is impossible for an operator condition
|
|
* with a NULL comparison constant to succeed, and we can reject it right
|
|
* away.
|
|
*
|
|
* However, we now also support "x IS NULL" clauses as search conditions,
|
|
* so in that case keep going. The planner has not filled in any
|
|
* particular strategy in this case, so set it to BTEqualStrategyNumber
|
|
* --- we can treat IS NULL as an equality operator for purposes of search
|
|
* strategy.
|
|
*
|
|
* Likewise, "x IS NOT NULL" is supported. We treat that as either "less
|
|
* than NULL" in a NULLS LAST index, or "greater than NULL" in a NULLS
|
|
* FIRST index.
|
|
*
|
|
* Note: someday we might have to fill in sk_collation from the index
|
|
* column's collation. At the moment this is a non-issue because we'll
|
|
* never actually call the comparison operator on a NULL.
|
|
*/
|
|
if (skey->sk_flags & SK_ISNULL) {
|
|
/* SK_ISNULL shouldn't be set in a row header scankey */
|
|
Assert(!(skey->sk_flags & SK_ROW_HEADER));
|
|
|
|
/* Set indoption flags in scankey (might be done already) */
|
|
skey->sk_flags |= addflags;
|
|
|
|
/* Set correct strategy for IS NULL or NOT NULL search */
|
|
if (skey->sk_flags & SK_SEARCHNULL) {
|
|
skey->sk_strategy = BTEqualStrategyNumber;
|
|
skey->sk_subtype = InvalidOid;
|
|
skey->sk_collation = InvalidOid;
|
|
} else if (skey->sk_flags & SK_SEARCHNOTNULL) {
|
|
skey->sk_strategy = (skey->sk_flags & SK_BT_NULLS_FIRST) ? BTGreaterStrategyNumber : BTLessStrategyNumber;
|
|
skey->sk_subtype = InvalidOid;
|
|
skey->sk_collation = InvalidOid;
|
|
} else {
|
|
/* regular qual, so it cannot be satisfied */
|
|
return false;
|
|
}
|
|
|
|
/* Needn't do the rest */
|
|
return true;
|
|
}
|
|
|
|
/* Adjust strategy for DESC, if we didn't already */
|
|
if ((addflags & SK_BT_DESC) && !(skey->sk_flags & SK_BT_DESC)) {
|
|
skey->sk_strategy = (uint16)BTCommuteStrategyNumber(skey->sk_strategy);
|
|
}
|
|
skey->sk_flags |= addflags;
|
|
|
|
/* If it's a row header, fix row member flags and strategies similarly */
|
|
if (skey->sk_flags & SK_ROW_HEADER) {
|
|
ScanKey subkey = (ScanKey)DatumGetPointer(skey->sk_argument);
|
|
for (;;) {
|
|
Assert(subkey->sk_flags & SK_ROW_MEMBER);
|
|
addflags = (uint16)(indoption[subkey->sk_attno - 1]) << SK_BT_INDOPTION_SHIFT;
|
|
if ((addflags & SK_BT_DESC) && !(subkey->sk_flags & SK_BT_DESC)) {
|
|
subkey->sk_strategy = (uint16)BTCommuteStrategyNumber(subkey->sk_strategy);
|
|
}
|
|
subkey->sk_flags |= addflags;
|
|
if (subkey->sk_flags & SK_ROW_END) {
|
|
break;
|
|
}
|
|
subkey++;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Mark a scankey as "required to continue the scan".
|
|
*
|
|
* Depending on the operator type, the key may be required for both scan
|
|
* directions or just one. Also, if the key is a row comparison header,
|
|
*
|
|
* we have to mark its first subsidiary ScanKey as required. (Subsequent
|
|
* subsidiary ScanKeys are normally for lower-order columns, and thus
|
|
* cannot be required, since they're after the first non-equality scankey.)
|
|
*
|
|
* Note: when we set required-key flag bits in a subsidiary scankey, we are
|
|
* scribbling on a data structure belonging to the index AM's caller, not on
|
|
* our private copy. This should be OK because the marking will not change
|
|
* from scan to scan within a query, and so we'd just re-mark the same way
|
|
* anyway on a rescan. Something to keep an eye on though.
|
|
*/
|
|
static void _bt_mark_scankey_required(ScanKey skey)
|
|
{
|
|
int addflags;
|
|
|
|
switch (skey->sk_strategy) {
|
|
case BTLessStrategyNumber:
|
|
case BTLessEqualStrategyNumber:
|
|
addflags = SK_BT_REQFWD;
|
|
break;
|
|
case BTEqualStrategyNumber:
|
|
addflags = SK_BT_REQFWD | SK_BT_REQBKWD;
|
|
break;
|
|
case BTGreaterEqualStrategyNumber:
|
|
case BTGreaterStrategyNumber:
|
|
addflags = SK_BT_REQBKWD;
|
|
break;
|
|
default:
|
|
ereport(ERROR, (errcode(ERRCODE_INDEX_CORRUPTED),
|
|
errmsg("unrecognized StrategyNumber: %d", (int)skey->sk_strategy)));
|
|
addflags = 0; /* keep compiler quiet */
|
|
break;
|
|
}
|
|
|
|
skey->sk_flags |= addflags;
|
|
if (skey->sk_flags & SK_ROW_HEADER) {
|
|
ScanKey subkey = (ScanKey)DatumGetPointer(skey->sk_argument);
|
|
|
|
/* First subkey should be same column/operator as the header */
|
|
Assert(subkey->sk_flags & SK_ROW_MEMBER);
|
|
Assert(subkey->sk_attno == skey->sk_attno);
|
|
Assert(subkey->sk_strategy == skey->sk_strategy);
|
|
subkey->sk_flags |= addflags;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Test whether an indextuple satisfies all the scankey conditions.
|
|
*
|
|
* If so, return the address of the index tuple on the index page.
|
|
* If not, return NULL.
|
|
*
|
|
* If the tuple fails to pass the qual, we also determine whether there's
|
|
* any need to continue the scan beyond this tuple, and set *continuescan
|
|
* accordingly. See comments for _bt_preprocess_keys(), above, about how
|
|
* this is done.
|
|
*
|
|
* scan: index scan descriptor (containing a search-type scankey)
|
|
* page: buffer page containing index tuple
|
|
* offnum: offset number of index tuple (must be a valid item!)
|
|
* dir: direction we are scanning in
|
|
* continuescan: output parameter (will be set correctly in all cases)
|
|
*
|
|
* Caller must hold pin and lock on the index page.
|
|
*/
|
|
IndexTuple _bt_checkkeys(IndexScanDesc scan, Page page, OffsetNumber offnum, ScanDirection dir, bool *continuescan)
|
|
{
|
|
ItemId iid = PageGetItemId(page, offnum);
|
|
bool tuple_alive = false;
|
|
IndexTuple tuple;
|
|
TupleDesc tupdesc;
|
|
BTScanOpaque so;
|
|
int keysz;
|
|
int ikey;
|
|
ScanKey key;
|
|
|
|
*continuescan = true; /* default assumption */
|
|
|
|
/*
|
|
* If the scan specifies not to return killed tuples, then we treat a
|
|
* killed tuple as not passing the qual. Most of the time, it's a win to
|
|
* not bother examining the tuple's index keys, but just return
|
|
* immediately with continuescan = true to proceed to the next tuple.
|
|
* However, if this is the last tuple on the page, we should check the
|
|
* index keys to prevent uselessly advancing to the next page.
|
|
*/
|
|
if (scan->ignore_killed_tuples && ItemIdIsDead(iid)) {
|
|
/* return immediately if there are more tuples on the page */
|
|
if (ScanDirectionIsForward(dir)) {
|
|
if (offnum < PageGetMaxOffsetNumber(page)) {
|
|
return NULL;
|
|
}
|
|
} else {
|
|
BTPageOpaqueInternal opaque = (BTPageOpaqueInternal)PageGetSpecialPointer(page);
|
|
if (offnum > P_FIRSTDATAKEY(opaque)) {
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* OK, we want to check the keys so we can set continuescan correctly,
|
|
* but we'll return NULL even if the tuple passes the key tests.
|
|
*/
|
|
tuple_alive = false;
|
|
} else {
|
|
tuple_alive = true;
|
|
}
|
|
|
|
tuple = (IndexTuple)PageGetItem(page, iid);
|
|
tupdesc = RelationGetDescr(scan->indexRelation);
|
|
so = (BTScanOpaque)scan->opaque;
|
|
keysz = so->numberOfKeys;
|
|
|
|
for (key = so->keyData, ikey = 0; ikey < keysz; key++, ikey++) {
|
|
Datum datum;
|
|
bool isNull = false;
|
|
bool test;
|
|
|
|
/* row-comparison keys need special processing */
|
|
if (key->sk_flags & SK_ROW_HEADER) {
|
|
if (_bt_check_rowcompare(key, tuple, tupdesc, dir, continuescan)) {
|
|
continue;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
datum = index_getattr(tuple, key->sk_attno, tupdesc, &isNull);
|
|
|
|
if (key->sk_flags & SK_ISNULL) {
|
|
/* Handle IS NULL/NOT NULL tests */
|
|
if (key->sk_flags & SK_SEARCHNULL) {
|
|
if (isNull) {
|
|
continue; /* tuple satisfies this qual */
|
|
}
|
|
} else {
|
|
Assert(key->sk_flags & SK_SEARCHNOTNULL);
|
|
if (!isNull) {
|
|
continue; /* tuple satisfies this qual */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Tuple fails this qual. If it's a required qual for the current
|
|
* scan direction, then we can conclude no further tuples will
|
|
* pass, either.
|
|
*/
|
|
if ((key->sk_flags & SK_BT_REQFWD) && ScanDirectionIsForward(dir)) {
|
|
*continuescan = false;
|
|
} else if ((key->sk_flags & SK_BT_REQBKWD) && ScanDirectionIsBackward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
|
|
/*
|
|
* In any case, this indextuple doesn't match the qual.
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
if (isNull) {
|
|
if (key->sk_flags & SK_BT_NULLS_FIRST) {
|
|
/*
|
|
* Since NULLs are sorted before non-NULLs, we know we have
|
|
* reached the lower limit of the range of values for this
|
|
* index attr. On a backward scan, we can stop if this qual
|
|
* is one of the "must match" subset. We can stop regardless
|
|
* of whether the qual is > or <, so long as it's required,
|
|
* because it's not possible for any future tuples to pass. On
|
|
* a forward scan, however, we must keep going, because we may
|
|
* have initially positioned to the start of the index.
|
|
*/
|
|
if ((key->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) && ScanDirectionIsBackward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
} else {
|
|
/*
|
|
* Since NULLs are sorted after non-NULLs, we know we have
|
|
* reached the upper limit of the range of values for this
|
|
* index attr. On a forward scan, we can stop if this qual is
|
|
* one of the "must match" subset. We can stop regardless of
|
|
* whether the qual is > or <, so long as it's required,
|
|
* because it's not possible for any future tuples to pass. On
|
|
* a backward scan, however, we must keep going, because we
|
|
* may have initially positioned to the end of the index.
|
|
*/
|
|
if ((key->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) && ScanDirectionIsForward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* In any case, this indextuple doesn't match the qual.
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
switch (key->sk_func.fn_oid) {
|
|
case F_INT8EQ:
|
|
test = (int64)datum == (int64)key->sk_argument;
|
|
break;
|
|
case F_INT48EQ:
|
|
test = (int64)(int32)datum == (int64)key->sk_argument;
|
|
break;
|
|
case F_INT84EQ:
|
|
test = (int64)datum == (int64)(int32)key->sk_argument;
|
|
break;
|
|
case F_INT84LE:
|
|
test = (int64)datum <= (int64)(int32)key->sk_argument;
|
|
break;
|
|
case F_INT84GE:
|
|
test = (int64)datum >= (int64)(int32)key->sk_argument;
|
|
break;
|
|
case F_INT4EQ:
|
|
test = (int32)datum == (int32)key->sk_argument;
|
|
break;
|
|
case F_INT4GT:
|
|
test = (int32)datum > (int32)key->sk_argument;
|
|
break;
|
|
case F_INT4LT:
|
|
test = (int32)datum < (int32)key->sk_argument;
|
|
break;
|
|
case F_INT4LE:
|
|
test = (int32)datum <= (int32)key->sk_argument;
|
|
break;
|
|
case F_INT4GE:
|
|
test = (int32)datum >= (int32)key->sk_argument;
|
|
break;
|
|
case F_DATE_LE:
|
|
test = (int32)datum <= (int32)key->sk_argument;
|
|
break;
|
|
case F_DATE_GE:
|
|
test = (int32)datum >= (int32)key->sk_argument;
|
|
break;
|
|
case F_DATE_EQ:
|
|
test = (int32)datum == (int32)key->sk_argument;
|
|
break;
|
|
|
|
default:
|
|
test = DatumGetBool(FunctionCall2Coll(&key->sk_func, key->sk_collation, datum, key->sk_argument));
|
|
}
|
|
|
|
if (!test) {
|
|
/*
|
|
* Tuple fails this qual. If it's a required qual for the current
|
|
* scan direction, then we can conclude no further tuples will
|
|
* pass, either.
|
|
*
|
|
* Note: because we stop the scan as soon as any required equality
|
|
* qual fails, it is critical that equality quals be used for the
|
|
* initial positioning in _bt_first() when they are available. See
|
|
* comments in _bt_first().
|
|
*/
|
|
if ((key->sk_flags & SK_BT_REQFWD) && ScanDirectionIsForward(dir)) {
|
|
*continuescan = false;
|
|
} else if ((key->sk_flags & SK_BT_REQBKWD) && ScanDirectionIsBackward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
|
|
/*
|
|
* In any case, this indextuple doesn't match the qual.
|
|
*/
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/* Check for failure due to it being a killed tuple. */
|
|
if (!tuple_alive) {
|
|
return NULL;
|
|
}
|
|
|
|
/* If we get here, the tuple passes all index quals. */
|
|
return tuple;
|
|
}
|
|
|
|
/*
|
|
* Test whether an indextuple satisfies a row-comparison scan condition.
|
|
*
|
|
* Return true if so, false if not. If not, also clear *continuescan if
|
|
* it's not possible for any future tuples in the current scan direction
|
|
* to pass the qual.
|
|
*
|
|
* This is a subroutine for _bt_checkkeys, which see for more info.
|
|
*/
|
|
bool _bt_check_rowcompare(ScanKey skey, IndexTuple tuple, TupleDesc tupdesc, ScanDirection dir,
|
|
bool *continuescan)
|
|
{
|
|
ScanKey subkey = (ScanKey)DatumGetPointer(skey->sk_argument);
|
|
int32 cmpresult = 0;
|
|
bool result = false;
|
|
|
|
/* First subkey should be same as the header says */
|
|
Assert(subkey->sk_attno == skey->sk_attno);
|
|
|
|
/* Loop over columns of the row condition */
|
|
for (;;) {
|
|
Datum datum;
|
|
bool isNull = false;
|
|
|
|
Assert(subkey->sk_flags & SK_ROW_MEMBER);
|
|
|
|
datum = index_getattr(tuple, subkey->sk_attno, tupdesc, &isNull);
|
|
if (isNull) {
|
|
if (subkey->sk_flags & SK_BT_NULLS_FIRST) {
|
|
/*
|
|
* Since NULLs are sorted before non-NULLs, we know we have
|
|
* reached the lower limit of the range of values for this
|
|
* index attr. On a backward scan, we can stop if this qual
|
|
* is one of the "must match" subset. We can stop regardless
|
|
* of whether the qual is > or <, so long as it's required,
|
|
* because it's not possible for any future tuples to pass. On
|
|
* a forward scan, however, we must keep going, because we may
|
|
* have initially positioned to the start of the index.
|
|
*/
|
|
if ((subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) && ScanDirectionIsBackward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
} else {
|
|
/*
|
|
* Since NULLs are sorted after non-NULLs, we know we have
|
|
* reached the upper limit of the range of values for this
|
|
* index attr. On a forward scan, we can stop if this qual is
|
|
* one of the "must match" subset. We can stop regardless of
|
|
* whether the qual is > or <, so long as it's required,
|
|
* because it's not possible for any future tuples to pass. On
|
|
* a backward scan, however, we must keep going, because we
|
|
* may have initially positioned to the end of the index.
|
|
*/
|
|
if ((subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) && ScanDirectionIsForward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* In any case, this indextuple doesn't match the qual.
|
|
*/
|
|
return false;
|
|
}
|
|
|
|
if (subkey->sk_flags & SK_ISNULL) {
|
|
/*
|
|
* Unlike the simple-scankey case, this isn't a disallowed case.
|
|
* But it can never match. If all the earlier row comparison
|
|
* columns are required for the scan direction, we can stop the
|
|
* scan, because there can't be another tuple that will succeed.
|
|
*/
|
|
if (subkey != (ScanKey)DatumGetPointer(skey->sk_argument)) {
|
|
subkey--;
|
|
}
|
|
if ((subkey->sk_flags & SK_BT_REQFWD) && ScanDirectionIsForward(dir)) {
|
|
*continuescan = false;
|
|
} else if ((subkey->sk_flags & SK_BT_REQBKWD) && ScanDirectionIsBackward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Perform the test --- three-way comparison not bool operator */
|
|
cmpresult =
|
|
DatumGetInt32(FunctionCall2Coll(&subkey->sk_func, subkey->sk_collation, datum, subkey->sk_argument));
|
|
|
|
if (subkey->sk_flags & SK_BT_DESC) {
|
|
cmpresult = -cmpresult;
|
|
}
|
|
|
|
/* Done comparing if unequal, else advance to next column */
|
|
if (cmpresult != 0) {
|
|
break;
|
|
}
|
|
|
|
if (subkey->sk_flags & SK_ROW_END) {
|
|
break;
|
|
}
|
|
subkey++;
|
|
}
|
|
|
|
/*
|
|
* At this point cmpresult indicates the overall result of the row
|
|
* comparison, and subkey points to the deciding column (or the last
|
|
* column if the result is "=").
|
|
*/
|
|
switch (subkey->sk_strategy) {
|
|
/* EQ and NE cases aren't allowed here */
|
|
case BTLessStrategyNumber:
|
|
result = (cmpresult < 0);
|
|
break;
|
|
case BTLessEqualStrategyNumber:
|
|
result = (cmpresult <= 0);
|
|
break;
|
|
case BTGreaterEqualStrategyNumber:
|
|
result = (cmpresult >= 0);
|
|
break;
|
|
case BTGreaterStrategyNumber:
|
|
result = (cmpresult > 0);
|
|
break;
|
|
default:
|
|
ereport(ERROR, (errcode(ERRCODE_INDEX_CORRUPTED),
|
|
errmsg("unrecognized RowCompareType: %d", (int)subkey->sk_strategy)));
|
|
result = false; /* keep compiler quiet */
|
|
break;
|
|
}
|
|
|
|
if (!result) {
|
|
/*
|
|
* Tuple fails this qual. If it's a required qual for the current
|
|
* scan direction, then we can conclude no further tuples will pass,
|
|
* either. Note we have to look at the deciding column, not
|
|
* necessarily the first or last column of the row condition.
|
|
*/
|
|
if ((subkey->sk_flags & SK_BT_REQFWD) && ScanDirectionIsForward(dir)) {
|
|
*continuescan = false;
|
|
} else if ((subkey->sk_flags & SK_BT_REQBKWD) && ScanDirectionIsBackward(dir)) {
|
|
*continuescan = false;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* _bt_killitems - set LP_DEAD state for items an indexscan caller has
|
|
* told us were killed
|
|
*
|
|
* scan->so contains information about the current page and killed tuples
|
|
* thereon (generally, this should only be called if so->numKilled > 0).
|
|
*
|
|
* The caller must have pin on so->currPos.buf, but may or may not have
|
|
* read-lock, as indicated by haveLock. Note that we assume read-lock
|
|
* is sufficient for setting LP_DEAD status (which is only a hint).
|
|
*
|
|
* We match items by heap TID before assuming they are the right ones to
|
|
* delete. We cope with cases where items have moved right due to insertions.
|
|
* If an item has moved off the current page due to a split, we'll fail to
|
|
* find it and do nothing (this is not an error case --- we assume the item
|
|
* will eventually get marked in a future indexscan). Note that because we
|
|
* hold pin on the target page continuously from initially reading the items
|
|
* until applying this function, VACUUM cannot have deleted any items from
|
|
* the page, and so there is no need to search left from the recorded offset.
|
|
* (This observation also guarantees that the item is still the right one
|
|
* to delete, which might otherwise be questionable since heap TIDs can get
|
|
* recycled.)
|
|
*/
|
|
void _bt_killitems(IndexScanDesc scan, bool haveLock)
|
|
{
|
|
BTScanOpaque so = (BTScanOpaque)scan->opaque;
|
|
Page page;
|
|
BTPageOpaqueInternal opaque;
|
|
OffsetNumber minoff;
|
|
OffsetNumber maxoff;
|
|
int i;
|
|
bool killedsomething = false;
|
|
Oid heapOid = IndexScanGetPartHeapOid(scan);
|
|
|
|
Assert(BufferIsValid(so->currPos.buf));
|
|
|
|
if (!haveLock) {
|
|
LockBuffer(so->currPos.buf, BT_READ);
|
|
}
|
|
|
|
page = BufferGetPage(so->currPos.buf);
|
|
opaque = (BTPageOpaqueInternal)PageGetSpecialPointer(page);
|
|
minoff = P_FIRSTDATAKEY(opaque);
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
|
|
for (i = 0; i < so->numKilled; i++) {
|
|
int itemIndex = so->killedItems[i];
|
|
BTScanPosItem *kitem = &so->currPos.items[itemIndex];
|
|
OffsetNumber offnum = kitem->indexOffset;
|
|
Oid partOid = kitem->partitionOid;
|
|
int2 bucketid = kitem->bucketid;
|
|
|
|
Assert(itemIndex >= so->currPos.firstItem && itemIndex <= so->currPos.lastItem);
|
|
if (offnum < minoff) {
|
|
continue; /* pure paranoia */
|
|
}
|
|
while (offnum <= maxoff) {
|
|
ItemId iid = PageGetItemId(page, offnum);
|
|
IndexTuple ituple = (IndexTuple)PageGetItem(page, iid);
|
|
|
|
bool killtuple = false;
|
|
|
|
if (btree_tuple_is_posting(ituple)) {
|
|
int posting_idx = i + 1;
|
|
int nposting = btree_tuple_get_nposting(ituple);
|
|
int j;
|
|
|
|
for (j = 0; j < nposting; j++) {
|
|
ItemPointer item = btree_tuple_get_posting_n(ituple, j);
|
|
|
|
if (!ItemPointerEquals(item, &kitem->heapTid))
|
|
break;
|
|
|
|
if (posting_idx < so->numKilled)
|
|
kitem = &so->currPos.items[so->killedItems[posting_idx++]];
|
|
}
|
|
|
|
if (j == nposting)
|
|
killtuple = true;
|
|
} else if (ItemPointerEquals(&ituple->t_tid, &kitem->heapTid)) {
|
|
Oid currPartOid = scan->xs_want_ext_oid ? index_getattr_tableoid(scan->indexRelation, ituple) : heapOid;
|
|
int2 currbktid =
|
|
scan->xs_want_bucketid ? index_getattr_bucketid(scan->indexRelation, ituple) : bucketid;
|
|
if (currPartOid == partOid && currbktid == bucketid) {
|
|
killtuple = true;
|
|
}
|
|
}
|
|
|
|
if (killtuple && !ItemIdIsDead(iid)) {
|
|
/* found the item */
|
|
ItemIdMarkDead(iid);
|
|
killedsomething = true;
|
|
break; /* out of inner search loop */
|
|
}
|
|
offnum = OffsetNumberNext(offnum);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Since this can be redone later if needed, it's treated the same as a
|
|
* commit-hint-bit status update for heap tuples: we mark the buffer dirty
|
|
* but don't make a WAL log entry.
|
|
*
|
|
* Whenever we mark anything LP_DEAD, we also set the page's
|
|
* BTP_HAS_GARBAGE flag, which is likewise just a hint.
|
|
*/
|
|
if (killedsomething) {
|
|
opaque->btpo_flags |= BTP_HAS_GARBAGE;
|
|
MarkBufferDirtyHint(so->currPos.buf, true);
|
|
}
|
|
|
|
if (!haveLock) {
|
|
LockBuffer(so->currPos.buf, BUFFER_LOCK_UNLOCK);
|
|
}
|
|
|
|
/*
|
|
* Always reset the scan state, so we don't look for same items on other
|
|
* pages.
|
|
*/
|
|
so->numKilled = 0;
|
|
}
|
|
|
|
/*
|
|
* The following routines manage a shared-memory area in which we track
|
|
* assignment of "vacuum cycle IDs" to currently-active btree vacuuming
|
|
* operations. There is a single counter which increments each time we
|
|
* start a vacuum to assign it a cycle ID. Since multiple vacuums could
|
|
* be active concurrently, we have to track the cycle ID for each active
|
|
* vacuum; this requires at most g_instance.shmem_cxt.MaxBackends entries (usually far fewer).
|
|
* We assume at most one vacuum can be active for a given index.
|
|
*
|
|
* Access to the shared memory area is controlled by BtreeVacuumLock.
|
|
* In principle we could use a separate lmgr locktag for each index,
|
|
* but a single LWLock is much cheaper, and given the short time that
|
|
* the lock is ever held, the concurrency hit should be minimal.
|
|
*/
|
|
typedef struct BTOneVacInfo {
|
|
LockRelId relid; /* global identifier of an index */
|
|
BTCycleId cycleid; /* cycle ID for its active VACUUM */
|
|
} BTOneVacInfoNode;
|
|
|
|
typedef struct BTVacInfo {
|
|
BTCycleId cycle_ctr; /* cycle ID most recently assigned */
|
|
int num_vacuums; /* number of currently active VACUUMs */
|
|
int max_vacuums; /* allocated length of vacuums[] array */
|
|
BTOneVacInfo vacuums[1]; /* VARIABLE LENGTH ARRAY */
|
|
} BTVacInfoNode;
|
|
|
|
/*
|
|
* _bt_vacuum_cycleid --- get the active vacuum cycle ID for an index,
|
|
* or zero if there is no active VACUUM
|
|
*
|
|
* Note: for correct interlocking, the caller must already hold pin and
|
|
* exclusive lock on each buffer it will store the cycle ID into. This
|
|
* ensures that even if a VACUUM starts immediately afterwards, it cannot
|
|
* process those pages until the page split is complete.
|
|
*/
|
|
BTCycleId _bt_vacuum_cycleid(const Relation rel)
|
|
{
|
|
BTCycleId result = 0;
|
|
int i;
|
|
|
|
/* Share lock is enough since this is a read-only operation */
|
|
LWLockAcquire(BtreeVacuumLock, LW_SHARED);
|
|
|
|
for (i = 0; i < t_thrd.index_cxt.btvacinfo->num_vacuums; i++) {
|
|
BTOneVacInfo *vac = &t_thrd.index_cxt.btvacinfo->vacuums[i];
|
|
|
|
if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
|
|
vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId &&
|
|
vac->relid.bktId == rel->rd_lockInfo.lockRelId.bktId) {
|
|
result = vac->cycleid;
|
|
break;
|
|
}
|
|
}
|
|
|
|
LWLockRelease(BtreeVacuumLock);
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* _bt_start_vacuum --- assign a cycle ID to a just-starting VACUUM operation
|
|
*
|
|
* Note: the caller must guarantee that it will eventually call
|
|
* _bt_end_vacuum, else we'll permanently leak an array slot. To ensure
|
|
* that this happens even in elog(FATAL) scenarios, the appropriate coding is not just
|
|
* a PG_TRY, but PG_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel))
|
|
*/
|
|
BTCycleId _bt_start_vacuum(Relation rel)
|
|
{
|
|
BTCycleId result;
|
|
int i;
|
|
BTOneVacInfo *vac = NULL;
|
|
|
|
LWLockAcquire(BtreeVacuumLock, LW_EXCLUSIVE);
|
|
|
|
/*
|
|
* Assign the next cycle ID, being careful to avoid zero as well as the
|
|
* reserved high values.
|
|
*/
|
|
result = ++(t_thrd.index_cxt.btvacinfo->cycle_ctr);
|
|
if (result == 0 || result > MAX_BT_CYCLE_ID) {
|
|
result = t_thrd.index_cxt.btvacinfo->cycle_ctr = 1;
|
|
}
|
|
|
|
/* Le's just make sure there'ts no entry already for this index */
|
|
for (i = 0; i < t_thrd.index_cxt.btvacinfo->num_vacuums; i++) {
|
|
vac = &t_thrd.index_cxt.btvacinfo->vacuums[i];
|
|
if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
|
|
vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId &&
|
|
vac->relid.bktId == rel->rd_lockInfo.lockRelId.bktId) {
|
|
/*
|
|
* Unlike most places in the backend, we have to explicitly
|
|
* release our LWLock before throwing an error. This is because
|
|
* we expect _bt_end_vacuum() to be called before transaction
|
|
* abort cleanup can run to release LWLocks.
|
|
*/
|
|
LWLockRelease(BtreeVacuumLock);
|
|
ereport(ERROR, (errcode(ERRCODE_INDEX_CORRUPTED),
|
|
errmsg("multiple active vacuums for index \"%s\"", RelationGetRelationName(rel))));
|
|
}
|
|
}
|
|
|
|
/* OK, add an entry */
|
|
if (t_thrd.index_cxt.btvacinfo->num_vacuums >= t_thrd.index_cxt.btvacinfo->max_vacuums) {
|
|
LWLockRelease(BtreeVacuumLock);
|
|
ereport(ERROR, (errcode(ERRCODE_INDEX_CORRUPTED), errmsg("out of btvacinfo slots")));
|
|
}
|
|
vac = &t_thrd.index_cxt.btvacinfo->vacuums[t_thrd.index_cxt.btvacinfo->num_vacuums];
|
|
vac->relid = rel->rd_lockInfo.lockRelId;
|
|
vac->cycleid = result;
|
|
t_thrd.index_cxt.btvacinfo->num_vacuums++;
|
|
|
|
LWLockRelease(BtreeVacuumLock);
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* _bt_end_vacuum --- mark a btree VACUUM operation as done
|
|
*
|
|
* Note: this is deliberately coded not to complain if no entry is found;
|
|
* this allows the caller to put PG_TRY around the start_vacuum operation.
|
|
*/
|
|
void _bt_end_vacuum(const Relation rel)
|
|
{
|
|
int i;
|
|
|
|
LWLockAcquire(BtreeVacuumLock, LW_EXCLUSIVE);
|
|
|
|
/* Find the array entry */
|
|
for (i = 0; i < t_thrd.index_cxt.btvacinfo->num_vacuums; i++) {
|
|
BTOneVacInfo *vac = &t_thrd.index_cxt.btvacinfo->vacuums[i];
|
|
if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
|
|
vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId &&
|
|
vac->relid.bktId == rel->rd_lockInfo.lockRelId.bktId) {
|
|
/* Remove it by shifting down the last entry */
|
|
*vac = t_thrd.index_cxt.btvacinfo->vacuums[t_thrd.index_cxt.btvacinfo->num_vacuums - 1];
|
|
t_thrd.index_cxt.btvacinfo->num_vacuums--;
|
|
break;
|
|
}
|
|
}
|
|
|
|
LWLockRelease(BtreeVacuumLock);
|
|
}
|
|
|
|
/*
|
|
* _bt_end_vacuum wrapped as an on_shmem_exit callback function
|
|
*/
|
|
void _bt_end_vacuum_callback(int code, Datum arg)
|
|
{
|
|
_bt_end_vacuum((Relation)DatumGetPointer(arg));
|
|
}
|
|
|
|
/*
|
|
* BTreeShmemSize --- report amount of shared memory space needed
|
|
*/
|
|
Size BTreeShmemSize(void)
|
|
{
|
|
Size size = offsetof(BTVacInfo, vacuums[0]);
|
|
size = add_size(size, mul_size((Size)g_instance.shmem_cxt.MaxBackends, sizeof(BTOneVacInfo)));
|
|
return size;
|
|
}
|
|
|
|
/*
|
|
* BTreeShmemInit --- initialize this module's shared memory
|
|
*/
|
|
void BTreeShmemInit(void)
|
|
{
|
|
bool found = false;
|
|
|
|
t_thrd.index_cxt.btvacinfo = (BTVacInfo *)ShmemInitStruct("BTree Vacuum State", BTreeShmemSize(), &found);
|
|
|
|
if (!IsUnderPostmaster) {
|
|
/* Initialize shared memory area */
|
|
Assert(!found);
|
|
|
|
/*
|
|
* It doesn't really matter what the cycle counter starts at, but
|
|
* having it always start the same doesn't seem good. Seed with
|
|
* low-order bits of time() instead.
|
|
*/
|
|
t_thrd.index_cxt.btvacinfo->cycle_ctr = (BTCycleId)time(NULL);
|
|
t_thrd.index_cxt.btvacinfo->num_vacuums = 0;
|
|
t_thrd.index_cxt.btvacinfo->max_vacuums = g_instance.shmem_cxt.MaxBackends;
|
|
} else {
|
|
Assert(found);
|
|
}
|
|
}
|
|
|
|
Datum btoptions(PG_FUNCTION_ARGS)
|
|
{
|
|
Datum reloptions = PG_GETARG_DATUM(0);
|
|
bool validate = PG_GETARG_BOOL(1);
|
|
bytea *result = NULL;
|
|
|
|
result = default_reloptions(reloptions, validate, RELOPT_KIND_BTREE);
|
|
if (result != NULL) {
|
|
PG_RETURN_BYTEA_P(result);
|
|
}
|
|
PG_RETURN_NULL();
|
|
}
|
|
|
|
/*
|
|
* _bt_nonkey_truncate() -- remove non-key (INCLUDE) attributes from index
|
|
* tuple.
|
|
*
|
|
* Transforms an ordinal B-tree leaf index tuple into pivot tuple to be used
|
|
* as hikey or non-leaf page tuple with downlink. Note that t_tid offset
|
|
* will be overritten in order to represent number of present tuple attributes.
|
|
*/
|
|
IndexTuple btree_truncate(Relation rel, IndexTuple lastleft, IndexTuple firstright, BTScanInsert itup_key)
|
|
{
|
|
Assert(!btree_tuple_is_pivot(lastleft));
|
|
Assert(!btree_tuple_is_pivot(firstright));
|
|
|
|
TupleDesc itupdesc = RelationGetDescr(rel);
|
|
int nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
|
|
int keepnatts = btree_num_keep_atts(rel, lastleft, firstright, itup_key);
|
|
|
|
#ifdef DEBUG_NO_TRUNCATE
|
|
keepnatts = nkeyatts + 1;
|
|
#endif
|
|
|
|
IndexTuple pivot = index_truncate_tuple(itupdesc, firstright, Min(keepnatts, nkeyatts));
|
|
|
|
if (btree_tuple_is_posting(pivot)) {
|
|
Assert(keepnatts == nkeyatts || keepnatts == nkeyatts + 1);
|
|
Assert(IndexRelationGetNumberOfAttributes(rel) == nkeyatts);
|
|
pivot->t_info &= ~INDEX_SIZE_MASK;
|
|
pivot->t_info |= MAXALIGN(btree_tuple_get_posting_off(firstright));
|
|
}
|
|
|
|
if (keepnatts <= nkeyatts) {
|
|
btree_tuple_set_num_of_atts(pivot, (uint16)keepnatts, false);
|
|
return pivot;
|
|
}
|
|
|
|
Size newsize = MAXALIGN(IndexTupleSize(pivot)) + MAXALIGN(sizeof(ItemPointerData));
|
|
IndexTuple tid_pivot = (IndexTuple)palloc0(newsize);
|
|
|
|
errno_t rc = memcpy_s(tid_pivot, newsize, pivot, MAXALIGN(IndexTupleSize(pivot)));
|
|
securec_check(rc, "", "");
|
|
pfree(pivot);
|
|
|
|
tid_pivot->t_info &= ~INDEX_SIZE_MASK;
|
|
tid_pivot->t_info |= newsize;
|
|
btree_tuple_set_num_of_atts(tid_pivot, (uint16)nkeyatts, true);
|
|
ItemPointer pivot_heaptid = btree_tuple_get_heap_tid(tid_pivot);
|
|
Assert(pivot_heaptid);
|
|
|
|
ItemPointerCopy(btree_tuple_get_max_heap_tid(lastleft), pivot_heaptid);
|
|
|
|
#ifndef DEBUG_NO_TRUNCATE
|
|
Assert(ItemPointerCompare(btree_tuple_get_max_heap_tid(lastleft), btree_tuple_get_heap_tid(firstright)) <= 0);
|
|
Assert(ItemPointerCompare(pivot_heaptid, btree_tuple_get_heap_tid(lastleft)) >= 0);
|
|
Assert(ItemPointerCompare(pivot_heaptid, btree_tuple_get_heap_tid(firstright)) <= 0);
|
|
#else
|
|
|
|
ItemPointerCopy(btree_tuple_get_heap_tid(firstright), pivot_heaptid);
|
|
ItemPointerSetOffsetNumber(pivot_heaptid, OffsetNumberPrev(ItemPointerGetOffsetNumber(pivot_heaptid)));
|
|
Assert(ItemPointerCompare(pivot_heaptid, btree_tuple_get_heap_tid(firstright)) < 0);
|
|
#endif
|
|
|
|
return tid_pivot;
|
|
}
|
|
|
|
static int btree_num_keep_atts(Relation rel, IndexTuple lastleft, IndexTuple firstright, BTScanInsert itup_key)
|
|
{
|
|
int num_key_atts = IndexRelationGetNumberOfKeyAttributes(rel);
|
|
if (!itup_key->heapkeyspace) {
|
|
return num_key_atts;
|
|
}
|
|
|
|
TupleDesc itupdesc = RelationGetDescr(rel);
|
|
int num_keep_atts = 1;
|
|
ScanKey scankey = itup_key->scankeys;
|
|
|
|
for (int attnum = 1; attnum <= num_key_atts; attnum++, scankey++) {
|
|
|
|
bool is_null_1, is_null_2;
|
|
Datum datum1 = index_getattr(lastleft, attnum, itupdesc, &is_null_1);
|
|
Datum datum2 = index_getattr(firstright, attnum, itupdesc, &is_null_2);
|
|
|
|
if (is_null_1 != is_null_2)
|
|
break;
|
|
|
|
if (!is_null_1 && DatumGetInt32(FunctionCall2Coll(&scankey->sk_func, scankey->sk_collation, datum1, datum2)) != 0)
|
|
break;
|
|
|
|
num_keep_atts++;
|
|
}
|
|
|
|
Assert(!itup_key->allequalimage || num_keep_atts == btree_num_keep_atts_fast(rel, lastleft, firstright));
|
|
|
|
return num_keep_atts;
|
|
}
|
|
|
|
int btree_num_keep_atts_fast(Relation rel, IndexTuple lastleft, IndexTuple firstright)
|
|
{
|
|
int num_key_atts = IndexRelationGetNumberOfKeyAttributes(rel);
|
|
TupleDesc itup_desc = RelationGetDescr(rel);
|
|
int num_keep_atts = 1;
|
|
|
|
for (int attnum = 1; attnum <= num_key_atts; attnum++) {
|
|
|
|
bool is_null_1, is_null_2;
|
|
Form_pg_attribute att;
|
|
Datum datum1 = index_getattr(lastleft, attnum, itup_desc, &is_null_1);
|
|
Datum datum2 = index_getattr(firstright, attnum, itup_desc, &is_null_2);
|
|
att = TupleDescAttr(itup_desc, attnum - 1);
|
|
|
|
if (is_null_1 != is_null_2)
|
|
break;
|
|
|
|
if (!is_null_1 && !DatumImageEq(datum1, datum2, att->attbyval, att->attlen))
|
|
break;
|
|
|
|
num_keep_atts++;
|
|
}
|
|
|
|
return num_keep_atts;
|
|
}
|
|
|
|
|
|
void btree_check_third_page(Relation rel, Relation heap, bool need_heaptid_space, Page page, IndexTuple tuple)
|
|
{
|
|
Size itemsz = MAXALIGN(IndexTupleSize(tuple));
|
|
if (itemsz <= BTREE_MAX_ITEM_SIZE(page))
|
|
return;
|
|
|
|
if (!need_heaptid_space && itemsz <= BTREE_MAX_ITEM_SIZE_NO_HEAP_TID(page)) {
|
|
return;
|
|
}
|
|
|
|
if (!P_ISLEAF((BTPageOpaqueInternal)PageGetSpecialPointer(page))) {
|
|
ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("cannot insert oversized tuple of size %lu on internal page of index \"%s\"",
|
|
(unsigned long)itemsz, RelationGetRelationName(rel))));
|
|
}
|
|
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("index row size %lu exceeds maximum %lu for index \"%s\"",
|
|
(unsigned long)itemsz,
|
|
(unsigned long)BTREE_MAX_ITEM_SIZE(page),
|
|
RelationGetRelationName(rel)),
|
|
errdetail("Index row references tuple (%u,%hu) in relation \"%s\".",
|
|
ItemPointerGetBlockNumber(&tuple->t_tid),
|
|
ItemPointerGetOffsetNumber(&tuple->t_tid),
|
|
heap ? RelationGetRelationName(heap) : "unknown"),
|
|
errhint("Values larger than 1/3 of a buffer page cannot be indexed.\n"
|
|
"Consider a function index of an MD5 hash of the value, "
|
|
"or use full text indexing.")));
|
|
}
|
|
|
|
bool btree_allequalimage(Relation rel, bool debugmessage)
|
|
{
|
|
if (t_thrd.proc->workingVersionNum < NBTREE_DEDUPLICATION_VERSION_NUM ||
|
|
IndexRelationGetNumberOfAttributes(rel) != IndexRelationGetNumberOfKeyAttributes(rel) || IsSystemRelation(rel))
|
|
return false;
|
|
|
|
bool allequalimage = true;
|
|
|
|
for (int i = 0; i < IndexRelationGetNumberOfKeyAttributes(rel); i++) {
|
|
Oid opfamily = rel->rd_opfamily[i];
|
|
Oid opcintype = rel->rd_opcintype[i];
|
|
Oid collation = rel->rd_indcollation[i];
|
|
Oid equalimage_proc = get_opfamily_proc(opfamily, opcintype, opcintype, BTEQUALIMAGE_PROC);
|
|
|
|
if (!OidIsValid(equalimage_proc) ||
|
|
!DatumGetBool(OidFunctionCall1Coll(equalimage_proc, collation, ObjectIdGetDatum(opcintype)))) {
|
|
allequalimage = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (debugmessage) {
|
|
if (allequalimage)
|
|
elog(DEBUG1, "index \"%s\" can safely use deduplication", RelationGetRelationName(rel));
|
|
else
|
|
elog(DEBUG1, "index \"%s\" cannot use deduplication", RelationGetRelationName(rel));
|
|
}
|
|
|
|
return allequalimage;
|
|
} |