page when it's read in, per pghackers discussion around 17-Feb. Add a
GUC variable zero_damaged_pages that causes the response to be a WARNING
followed by zeroing the page, rather than the normal ERROR; this is per
Hiroshi's suggestion that there needs to be a way to get at the data
in the rest of the table.
(materialization into a tuple store) discussed on pgsql-hackers earlier.
I've updated the documentation and the regression tests.
Notes on the implementation:
- I needed to change the tuple store API slightly -- it assumes that it
won't be used to hold data across transaction boundaries, so the temp
files that it uses for on-disk storage are automatically reclaimed at
end-of-transaction. I added a flag to tuplestore_begin_heap() to control
this behavior. Is changing the tuple store API in this fashion OK?
- in order to store executor results in a tuple store, I added a new
CommandDest. This works well for the most part, with one exception: the
current DestFunction API doesn't provide enough information to allow the
Executor to store results into an arbitrary tuple store (where the
particular tuple store to use is chosen by the call site of
ExecutorRun). To workaround this, I've temporarily hacked up a solution
that works, but is not ideal: since the receiveTuple DestFunction is
passed the portal name, we can use that to lookup the Portal data
structure for the cursor and then use that to get at the tuple store the
Portal is using. This unnecessarily ties the Portal code with the
tupleReceiver code, but it works...
The proper fix for this is probably to change the DestFunction API --
Tom suggested passing the full QueryDesc to the receiveTuple function.
In that case, callers of ExecutorRun could "subclass" QueryDesc to add
any additional fields that their particular CommandDest needed to get
access to. This approach would work, but I'd like to think about it for
a little bit longer before deciding which route to go. In the mean time,
the code works fine, so I don't think a fix is urgent.
- (semi-related) I added a NO SCROLL keyword to DECLARE CURSOR, and
adjusted the behavior of SCROLL in accordance with the discussion on
-hackers.
- (unrelated) Cleaned up some SGML markup in sql.sgml, copy.sgml
Neil Conway
them as arrays of the internal datatype. This requires treating the
stavalues columns as 'anyarray' rather than 'text[]', which is not 100%
kosher but seems to work fine for the purposes we need for pg_statistic.
Perhaps in the future 'anyarray' will be allowed more generally.
refers to a non-DISTINCT output column of a DISTINCT ON subquery, or
if it refers to a function-returning-set, we cannot push it down.
But the old implementation refused to push down *any* quals if the
subquery had any such 'dangerous' outputs. Now we just look at the
output columns actually referenced by each qual expression. More code
than before, but probably no slower since we don't make unnecessary checks.
some of the algorithms for higher functions. I see about a factor of ten
speedup on the 'numeric' regression test, but it's unlikely that that test
is representative of real-world applications.
initdb forced due to change of on-disk representation for NUMERIC.
Add ALTER SEQUENCE to modify min/max/increment/cache/cycle values
Also updated create sequence docs to mention NO MINVALUE, & NO MAXVALUE.
New Files:
doc/src/sgml/ref/alter_sequence.sgml
src/test/regress/expected/sequence.out
src/test/regress/sql/sequence.sql
ALTER SEQUENCE is NOT transactional. It behaves similarly to setval().
It matches the proposed SQL200N spec, as well as Oracle in most ways --
Oracle lacks RESTART WITH for some strange reason.
--
Rod Taylor <rbt@rbt.ca>
> >
> > - Add check in pg_dump to see if the value returned is the max /min
> > values and replace with NO MAXVALUE, NO MINVALUE.
> >
> > - Change START and INCREMENT to use START WITH and INCREMENT BY syntax.
> > This makes it a touch easier to port to other databases with sequences
> > (Oracle). PostgreSQL supports both syntaxes already.
>
> + char bufm[100],
> + bufx[100];
>
> This seems to be an arbitary size. Why not set it to the actual maximum
> length?
>
> Also:
>
> + snprintf(bufm, 100, INT64_FORMAT, SEQ_MINVALUE);
> + snprintf(bufx, 100, INT64_FORMAT, SEQ_MAXVALUE);
>
> sizeof(bufm), sizeof(bufx) is probably the more
> maintenance-friendly/standard way to do it.
I changed the code to use sizeof - but will wait for a response from
Peter before changing the size. It's consistent throughout the sequence
code to be 100 for this purpose.
Rod Taylor <rbt@rbt.ca>
> weird behavior across fork boundaries; (b) the additional memory space
> that has to be duplicated into child processes will cost something per
> child launch, even if the child never uses it. But these are only
> arguments that it might not *always* be a prudent thing to do, not that
> we shouldn't give the DBA the tool to do it if he wants. So fire away.
Here is a patch for the above, including a documentation update. It
creates a new GUC variable "preload_libraries", that accepts a list in
the form:
preload_libraries = '$libdir/mylib1:initfunc,$libdir/mylib2'
If ":initfunc" is omitted or not found, no initialization function is
executed, but the library is still preloaded. If "$libdir/mylib" isn't
found, the postmaster refuses to start.
In my testing with PL/R, it reduces the first call to a PL/R function
(after connecting) from almost 2 seconds, down to about 8 ms.
Joe Conway
utility statement (DeclareCursorStmt) with a SELECT query dangling from
it, rather than a SELECT query with a few unusual fields in it. Add
code to determine whether a planned query can safely be run backwards.
If DECLARE CURSOR specifies SCROLL, ensure that the plan can be run
backwards by adding a Materialize plan node if it can't. Without SCROLL,
you get an error if you try to fetch backwards from a cursor that can't
handle it. (There is still some discussion about what the exact
behavior should be, but this is necessary infrastructure in any case.)
Along the way, make EXPLAIN DECLARE CURSOR work.
entire contents of the subplan into the tuplestore before we can return
any tuples. Instead, the tuplestore holds what we've already read, and
we fetch additional rows from the subplan as needed. Random access to
the previously-read rows works with the tuplestore, and doesn't affect
the state of the partially-read subplan. This is a step towards fixing
the problems with cursors over complex queries --- we don't want to
stick in Materialize nodes if they'll prevent quick startup for a cursor.
cleaning out temp namespaces. We don't really want the server log to be
cluttered with 'Drop cascades to table foo' every time someone uses a
temp table...
problems in applications that may have a large number of files open,
such that libpq's socket number exceeds the range supported by fd_set.
From Chris Brown.
at database shutdown, and then load it again at database startup. This
preserves our hard-won knowledge of free space across restarts (given
an orderly shutdown, that is).
Adjustable threshold is gone in favor of keeping track of total requested
page storage and doling out proportional fractions to each relation
(with a minimum amount per relation, and some quantization of the results
to avoid thrashing with small changes in page counts). Provide special-
case code for indexes so as not to waste space storing useless page
free space counts. Restructure internal data storage to be a flat array
instead of list-of-chunks; this may cost a little more work in data
copying when reorganizing, but allows binary search to be used during
lookup_fsm_page_entry().
end of a btree index. This isn't super-effective, since we won't move
nondeletable pages, but it's better than nothing. Also, improve stats
displayed during VACUUM VERBOSE.
deleting multiple index entries on a single index page. This makes for
a very substantial reduction in the amount of WAL traffic during a
large delete operation.
setting timezone-related variables during transaction start. They were
not used anyway in platforms that HAVE_TM_ZONE or HAVE_INT_TIMEZONE,
which it appears is *all* the platforms we are currently supporting.
For platforms that have neither, we now only support UTC or numeric-
offset-from-UTC timezones.
now knows what to do upon hitting a dead page (in theory anyway, it's
untested...). Add a post-VACUUM-cleanup entry point for index AMs, to
provide a place for dead-page scavenging to happen.
Also, fix oversight that broke btpo_prev links in temporary indexes.
initdb forced due to additions in pg_am.
support btree compaction, as per proposal of a few days ago. btree index
pages no longer store parent links, instead they have a level indicator
(counting up from zero for leaf pages). The FixBTree recovery logic is
removed, and replaced by code that detects missing parent-level insertions
during WAL replay. Also, generate appropriate WAL entries when updating
btree metapage and when building a btree index from scratch. I believe
btree indexes are now completely WAL-legal for the first time.
initdb forced due to index and WAL changes.
answer when SET TIMEZONE has been done since the start of the current
transaction. Per bug report from Robert Haas.
I plan some futher cleanup in HEAD, but this is a low-risk patch for
the immediate issue in 7.3.
correctly. See following thread for more details.
Subject: [HACKERS] client_encoding directive is ignored in postgresql.conf
From: Tatsuo Ishii <t-ishii@sra.co.jp>
Date: Wed, 29 Jan 2003 22:24:04 +0900 (JST)
implementation
of '\e' history tracking for systems that have a readline compatability
library without replace_history_entry. I fall back to pushing the query
onto the history stack after the \e, rather than replacing it.
The patch adds one more place to look for readline headers, and a test
for replace_history_entry. I've only included the patch for configure.in
Ross J. Reedstrom
RelOid_pg_class, and transaction locks XactLockTableId. RelId is renamed
to objId.
- LockObject() and UnlockObject() functions created, and their use
sprinkled throughout the code to do descent locking for domains and
types. They accept lock modes AccessShare and AccessExclusive, as we
only really need a 'read' and 'write' lock at the moment. Most locking
cases are held until the end of the transaction.
This fixes the cases Tom mentioned earlier in regards to locking with
Domains. If the patch is good, I'll work on cleaning up issues with
other database objects that have this problem (most of them).
Rod Taylor
