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2a600a93c7
This patch makes sizeof(Datum) be 8 on all platforms including 32-bit ones. The objective is to allow USE_FLOAT8_BYVAL to be true everywhere, and in consequence to remove a lot of code that is specific to pass-by-reference handling of float8, int8, etc. The code for abbreviated sort keys can be simplified similarly. In this way we can reduce the maintenance effort involved in supporting 32-bit platforms, without going so far as to actually desupport them. Since Datum is strictly an in-memory concept, this has no impact on on-disk storage, though an initdb or pg_upgrade will be needed to fix affected catalog entries. We have required platforms to support [u]int64 for ages, so this breaks no supported platform. We can expect that this change will make 32-bit builds a bit slower and more memory-hungry, although being able to use pass-by-value handling of 8-byte types may buy back some of that. But we stopped optimizing for 32-bit cases a long time ago, and this seems like just another step on that path. This initial patch simply forces the correct type definition and USE_FLOAT8_BYVAL setting, and cleans up a couple of minor compiler complaints that ensued. This is sufficient for testing purposes. In the wake of a bunch of Datum-conversion cleanups by Peter Eisentraut, this now compiles cleanly with gcc on a 32-bit platform. (I'd only tested the previous version with clang, which it turns out is less picky than gcc about width-changing coercions.) There is a good deal of now-dead code that I'll remove in separate follow-up patches. A catversion bump is required because this affects initial catalog contents (on 32-bit machines) in two ways: pg_type.typbyval changes for some built-in types, and Const nodes in stored views/rules will now have 8 bytes not 4 for pass-by-value types. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Discussion: https://postgr.es/m/1749799.1752797397@sss.pgh.pa.us
359 lines
13 KiB
C
359 lines
13 KiB
C
/*------------------------------------------------------------------------
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* PostgreSQL manual configuration settings
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*
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* This file contains various configuration symbols and limits. In
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* all cases, changing them is only useful in very rare situations or
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* for developers. If you edit any of these, be sure to do a *full*
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* rebuild (and an initdb if noted).
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*
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* Portions Copyright (c) 1996-2025, 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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* src/include/pg_config_manual.h
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*------------------------------------------------------------------------
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*/
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/*
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* This is the default value for wal_segment_size to be used when initdb is run
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* without the --wal-segsize option. It must be a valid segment size.
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*/
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#define DEFAULT_XLOG_SEG_SIZE (16*1024*1024)
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/*
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* Maximum length for identifiers (e.g. table names, column names,
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* function names). Names actually are limited to one fewer byte than this,
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* because the length must include a trailing zero byte.
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*
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* Changing this requires an initdb.
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*/
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#define NAMEDATALEN 64
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/*
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* Maximum number of arguments to a function.
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*
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* The minimum value is 8 (GIN indexes use 8-argument support functions).
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* The maximum possible value is around 600 (limited by index tuple size in
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* pg_proc's index; BLCKSZ larger than 8K would allow more). Values larger
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* than needed will waste memory and processing time, but do not directly
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* cost disk space.
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*
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* Changing this does not require an initdb, but it does require a full
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* backend recompile (including any user-defined C functions).
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*/
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#define FUNC_MAX_ARGS 100
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/*
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* When creating a product derived from PostgreSQL with changes that cause
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* incompatibilities for loadable modules, it is recommended to change this
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* string so that dfmgr.c can refuse to load incompatible modules with a clean
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* error message. Typical examples that cause incompatibilities are any
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* changes to node tags or node structures. (Note that dfmgr.c already
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* detects common sources of incompatibilities due to major version
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* differences and due to some changed compile-time constants. This setting
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* is for catching anything that cannot be detected in a straightforward way.)
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*
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* There is no prescribed format for the string. The suggestion is to include
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* product or company name, and optionally any internally-relevant ABI
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* version. Example: "ACME Postgres/1.2". Note that the string will appear
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* in a user-facing error message if an ABI mismatch is detected.
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*/
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#define FMGR_ABI_EXTRA "PostgreSQL"
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/*
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* Maximum number of columns in an index. There is little point in making
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* this anything but a multiple of 32, because the main cost is associated
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* with index tuple header size (see access/itup.h).
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*
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* Changing this requires an initdb.
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*/
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#define INDEX_MAX_KEYS 32
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/*
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* Maximum number of columns in a partition key
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*/
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#define PARTITION_MAX_KEYS 32
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/*
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* This symbol is now vestigial: built-in 8-byte types, including float8,
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* int8, and timestamp, are always passed by value since we require Datum
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* to be wide enough to permit that. We continue to define the symbol here
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* so as not to unnecessarily break extension code.
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*/
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#define USE_FLOAT8_BYVAL 1
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/*
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* MAXPGPATH: standard size of a pathname buffer in PostgreSQL (hence,
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* maximum usable pathname length is one less).
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*
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* We'd use a standard system header symbol for this, if there weren't
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* so many to choose from: MAXPATHLEN, MAX_PATH, PATH_MAX are all
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* defined by different "standards", and often have different values
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* on the same platform! So we just punt and use a reasonably
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* generous setting here.
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*/
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#define MAXPGPATH 1024
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/*
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* You can try changing this if you have a machine with bytes of
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* another size, but no guarantee...
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*/
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#define BITS_PER_BYTE 8
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/*
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* Preferred alignment for disk I/O buffers. On some CPUs, copies between
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* user space and kernel space are significantly faster if the user buffer
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* is aligned on a larger-than-MAXALIGN boundary. Ideally this should be
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* a platform-dependent value, but for now we just hard-wire it.
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*/
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#define ALIGNOF_BUFFER 32
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/*
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* If EXEC_BACKEND is defined, the postmaster uses an alternative method for
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* starting subprocesses: Instead of simply using fork(), as is standard on
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* Unix platforms, it uses fork()+exec() or something equivalent on Windows,
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* as well as lots of extra code to bring the required global state to those
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* new processes. This must be enabled on Windows (because there is no
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* fork()). On other platforms, it's only useful for verifying those
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* otherwise Windows-specific code paths.
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*/
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#if defined(WIN32) && !defined(__CYGWIN__)
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#define EXEC_BACKEND
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#endif
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/*
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* USE_POSIX_FADVISE controls whether Postgres will attempt to use the
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* posix_fadvise() kernel call. Usually the automatic configure tests are
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* sufficient, but some older Linux distributions had broken versions of
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* posix_fadvise(). If necessary you can remove the #define here.
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*/
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#if HAVE_DECL_POSIX_FADVISE && defined(HAVE_POSIX_FADVISE)
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#define USE_POSIX_FADVISE
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#endif
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/*
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* USE_PREFETCH code should be compiled only if we have a way to implement
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* prefetching. (This is decoupled from USE_POSIX_FADVISE because there
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* might in future be support for alternative low-level prefetch APIs,
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* as well as platform-specific APIs defined elsewhere.)
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*/
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#ifdef USE_POSIX_FADVISE
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#define USE_PREFETCH
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#endif
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/*
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* Default and maximum values for backend_flush_after, bgwriter_flush_after
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* and checkpoint_flush_after; measured in blocks. Currently, these are
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* enabled by default if sync_file_range() exists, ie, only on Linux. Perhaps
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* we could also enable by default if we have mmap and msync(MS_ASYNC)?
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*/
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#ifdef HAVE_SYNC_FILE_RANGE
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#define DEFAULT_BACKEND_FLUSH_AFTER 0 /* never enabled by default */
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#define DEFAULT_BGWRITER_FLUSH_AFTER 64
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#define DEFAULT_CHECKPOINT_FLUSH_AFTER 32
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#else
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#define DEFAULT_BACKEND_FLUSH_AFTER 0
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#define DEFAULT_BGWRITER_FLUSH_AFTER 0
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#define DEFAULT_CHECKPOINT_FLUSH_AFTER 0
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#endif
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/* upper limit for all three variables */
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#define WRITEBACK_MAX_PENDING_FLUSHES 256
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/*
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* USE_SSL code should be compiled only when compiling with an SSL
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* implementation.
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*/
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#ifdef USE_OPENSSL
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#define USE_SSL
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#endif
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/*
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* This is the default directory in which AF_UNIX socket files are
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* placed. Caution: changing this risks breaking your existing client
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* applications, which are likely to continue to look in the old
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* directory. But if you just hate the idea of sockets in /tmp,
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* here's where to twiddle it. You can also override this at runtime
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* with the postmaster's -k switch.
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*
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* If set to an empty string, then AF_UNIX sockets are not used by default: A
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* server will not create an AF_UNIX socket unless the run-time configuration
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* is changed, a client will connect via TCP/IP by default and will only use
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* an AF_UNIX socket if one is explicitly specified.
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*
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* This is done by default on Windows because there is no good standard
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* location for AF_UNIX sockets and many installations on Windows don't
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* support them yet.
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*/
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#ifndef WIN32
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#define DEFAULT_PGSOCKET_DIR "/tmp"
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#else
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#define DEFAULT_PGSOCKET_DIR ""
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#endif
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/*
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* This is the default event source for Windows event log.
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*/
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#define DEFAULT_EVENT_SOURCE "PostgreSQL"
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/*
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* Assumed cache line size. This doesn't affect correctness, but can be used
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* for low-level optimizations. This is mostly used to pad various data
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* structures, to ensure that highly-contended fields are on different cache
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* lines. Too small a value can hurt performance due to false sharing, while
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* the only downside of too large a value is a few bytes of wasted memory.
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* The default is 128, which should be large enough for all supported
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* platforms.
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*/
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#define PG_CACHE_LINE_SIZE 128
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/*
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* Assumed alignment requirement for direct I/O. 4K corresponds to common
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* sector and memory page size.
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*/
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#define PG_IO_ALIGN_SIZE 4096
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/*
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*------------------------------------------------------------------------
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* The following symbols are for enabling debugging code, not for
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* controlling user-visible features or resource limits.
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*------------------------------------------------------------------------
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*/
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/*
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* Force use of the non-recursive JSON parser in all cases. This is useful
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* to validate the working of the parser, and the regression tests should
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* pass except for some different error messages about the stack limit.
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*/
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/* #define FORCE_JSON_PSTACK */
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/*
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* Include Valgrind "client requests", mostly in the memory allocator, so
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* Valgrind understands PostgreSQL memory contexts. This permits detecting
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* memory errors that Valgrind would not detect on a vanilla build. It also
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* enables detection of buffer accesses that take place without holding a
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* buffer pin (or without holding a buffer lock in the case of index access
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* methods that superimpose their own custom client requests on top of the
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* generic bufmgr.c requests).
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*
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* "make installcheck" is significantly slower under Valgrind. The client
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* requests fall in hot code paths, so USE_VALGRIND slows execution by a few
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* percentage points even when not run under Valgrind.
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*
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* Do not try to test the server under Valgrind without having built the
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* server with USE_VALGRIND; else you will get false positives from sinval
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* messaging (see comments in AddCatcacheInvalidationMessage). It's also
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* important to use the suppression file src/tools/valgrind.supp to
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* exclude other known false positives.
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*
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* You should normally use MEMORY_CONTEXT_CHECKING with USE_VALGRIND;
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* instrumentation of repalloc() is inferior without it.
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*/
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/* #define USE_VALGRIND */
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/*
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* Define this to cause pfree()'d memory to be cleared immediately, to
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* facilitate catching bugs that refer to already-freed values.
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* Right now, this gets defined automatically if --enable-cassert.
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*/
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#ifdef USE_ASSERT_CHECKING
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#define CLOBBER_FREED_MEMORY
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#endif
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/*
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* Define this to check memory allocation errors (scribbling on more
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* bytes than were allocated). Right now, this gets defined
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* automatically if --enable-cassert or USE_VALGRIND.
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*/
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#if defined(USE_ASSERT_CHECKING) || defined(USE_VALGRIND)
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#define MEMORY_CONTEXT_CHECKING
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#endif
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/*
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* Define this to cause palloc()'d memory to be filled with random data, to
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* facilitate catching code that depends on the contents of uninitialized
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* memory. Caution: this is horrendously expensive.
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*/
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/* #define RANDOMIZE_ALLOCATED_MEMORY */
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/*
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* For cache-invalidation debugging, define DISCARD_CACHES_ENABLED to enable
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* use of the debug_discard_caches GUC to aggressively flush
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* syscache/relcache/relsynccache entries whenever it's possible to deliver
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* invalidations. See AcceptInvalidationMessages() in
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* src/backend/utils/cache/inval.c for details.
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*
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* USE_ASSERT_CHECKING builds default to enabling this. It's possible to use
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* DISCARD_CACHES_ENABLED without a cassert build and the implied
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* CLOBBER_FREED_MEMORY and MEMORY_CONTEXT_CHECKING options, but it's unlikely
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* to be as effective at identifying problems.
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*/
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/* #define DISCARD_CACHES_ENABLED */
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#if defined(USE_ASSERT_CHECKING) && !defined(DISCARD_CACHES_ENABLED)
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#define DISCARD_CACHES_ENABLED
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#endif
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/*
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* Backwards compatibility for the older compile-time-only clobber-cache
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* macros.
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*/
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#if !defined(DISCARD_CACHES_ENABLED) && (defined(CLOBBER_CACHE_ALWAYS) || defined(CLOBBER_CACHE_RECURSIVELY))
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#define DISCARD_CACHES_ENABLED
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#endif
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/*
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* Recover memory used for relcache entries when invalidated. See
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* RelationBuildDesc() in src/backend/utils/cache/relcache.c.
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*
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* This is active automatically for clobber-cache builds when clobbering is
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* active, but can be overridden here by explicitly defining
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* RECOVER_RELATION_BUILD_MEMORY. Define to 1 to always free relation cache
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* memory even when clobber is off, or to 0 to never free relation cache
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* memory even when clobbering is on.
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*/
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/* #define RECOVER_RELATION_BUILD_MEMORY 0 */ /* Force disable */
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/* #define RECOVER_RELATION_BUILD_MEMORY 1 */ /* Force enable */
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/*
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* Define DEBUG_NODE_TESTS_ENABLED to enable use of the GUCs
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* debug_copy_parse_plan_trees, debug_write_read_parse_plan_trees, and
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* debug_raw_expression_coverage_test, to test coverage of node support
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* functions in src/backend/nodes/.
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*
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* USE_ASSERT_CHECKING builds default to enabling this.
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*/
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/* #define DEBUG_NODE_TESTS_ENABLED */
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#if defined(USE_ASSERT_CHECKING) && !defined(DEBUG_NODE_TESTS_ENABLED)
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#define DEBUG_NODE_TESTS_ENABLED
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#endif
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/*
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* Backwards compatibility for the older compile-time-only node-tests macros.
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*/
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#if !defined(DEBUG_NODE_TESTS_ENABLED) && (defined(COPY_PARSE_PLAN_TREES) || defined(WRITE_READ_PARSE_PLAN_TREES) || defined(RAW_EXPRESSION_COVERAGE_TEST))
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#define DEBUG_NODE_TESTS_ENABLED
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#endif
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/*
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* Define this to force Bitmapset reallocation on each modification. Helps
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* to find dangling pointers to Bitmapset's.
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*/
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/* #define REALLOCATE_BITMAPSETS */
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/*
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* Enable debugging print statements for lock-related operations.
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*/
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/* #define LOCK_DEBUG */
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/*
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* Enable debugging print statements for WAL-related operations; see
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* also the wal_debug GUC var.
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*/
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/* #define WAL_DEBUG */
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/*
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* Enable tracing of syncscan operations (see also the trace_syncscan GUC var).
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*/
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/* #define TRACE_SYNCSCAN */
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