codekingpro/portable-devtools

1/*------------------------------------------------------------------------2 * PostgreSQL manual configuration settings3 *4 * This file contains various configuration symbols and limits.  In5 * all cases, changing them is only useful in very rare situations or6 * for developers.  If you edit any of these, be sure to do a *full*7 * rebuild (and an initdb if noted).8 *9 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group10 * Portions Copyright (c) 1994, Regents of the University of California11 *12 * src/include/pg_config_manual.h13 *------------------------------------------------------------------------14 */15 16/*17 * This is the default value for wal_segment_size to be used when initdb is run18 * without the --wal-segsize option.  It must be a valid segment size.19 */20#define DEFAULT_XLOG_SEG_SIZE	(16*1024*1024)21 22/*23 * Maximum length for identifiers (e.g. table names, column names,24 * function names).  Names actually are limited to one fewer byte than this,25 * because the length must include a trailing zero byte.26 *27 * Changing this requires an initdb.28 */29#define NAMEDATALEN 6430 31/*32 * Maximum number of arguments to a function.33 *34 * The minimum value is 8 (GIN indexes use 8-argument support functions).35 * The maximum possible value is around 600 (limited by index tuple size in36 * pg_proc's index; BLCKSZ larger than 8K would allow more).  Values larger37 * than needed will waste memory and processing time, but do not directly38 * cost disk space.39 *40 * Changing this does not require an initdb, but it does require a full41 * backend recompile (including any user-defined C functions).42 */43#define FUNC_MAX_ARGS		10044 45/*46 * When creating a product derived from PostgreSQL with changes that cause47 * incompatibilities for loadable modules, it is recommended to change this48 * string so that dfmgr.c can refuse to load incompatible modules with a clean49 * error message.  Typical examples that cause incompatibilities are any50 * changes to node tags or node structures.  (Note that dfmgr.c already51 * detects common sources of incompatibilities due to major version52 * differences and due to some changed compile-time constants.  This setting53 * is for catching anything that cannot be detected in a straightforward way.)54 *55 * There is no prescribed format for the string.  The suggestion is to include56 * product or company name, and optionally any internally-relevant ABI57 * version.  Example: "ACME Postgres/1.2".  Note that the string will appear58 * in a user-facing error message if an ABI mismatch is detected.59 */60#define FMGR_ABI_EXTRA		"PostgreSQL"61 62/*63 * Maximum number of columns in an index.  There is little point in making64 * this anything but a multiple of 32, because the main cost is associated65 * with index tuple header size (see access/itup.h).66 *67 * Changing this requires an initdb.68 */69#define INDEX_MAX_KEYS		3270 71/*72 * Maximum number of columns in a partition key73 */74#define PARTITION_MAX_KEYS	3275 76/*77 * Decide whether built-in 8-byte types, including float8, int8, and78 * timestamp, are passed by value.  This is on by default if sizeof(Datum) >=79 * 8 (that is, on 64-bit platforms).  If sizeof(Datum) < 8 (32-bit platforms),80 * this must be off.  We keep this here as an option so that it is easy to81 * test the pass-by-reference code paths on 64-bit platforms.82 *83 * Changing this requires an initdb.84 */85#if SIZEOF_VOID_P >= 886#define USE_FLOAT8_BYVAL 187#endif88 89/*90 * When we don't have native spinlocks, we use semaphores to simulate them.91 * Decreasing this value reduces consumption of OS resources; increasing it92 * may improve performance, but supplying a real spinlock implementation is93 * probably far better.94 */95#define NUM_SPINLOCK_SEMAPHORES		12896 97/*98 * When we have neither spinlocks nor atomic operations support we're99 * implementing atomic operations on top of spinlock on top of semaphores. To100 * be safe against atomic operations while holding a spinlock separate101 * semaphores have to be used.102 */103#define NUM_ATOMICS_SEMAPHORES		64104 105/*106 * MAXPGPATH: standard size of a pathname buffer in PostgreSQL (hence,107 * maximum usable pathname length is one less).108 *109 * We'd use a standard system header symbol for this, if there weren't110 * so many to choose from: MAXPATHLEN, MAX_PATH, PATH_MAX are all111 * defined by different "standards", and often have different values112 * on the same platform!  So we just punt and use a reasonably113 * generous setting here.114 */115#define MAXPGPATH		1024116 117/*118 * You can try changing this if you have a machine with bytes of119 * another size, but no guarantee...120 */121#define BITS_PER_BYTE		8122 123/*124 * Preferred alignment for disk I/O buffers.  On some CPUs, copies between125 * user space and kernel space are significantly faster if the user buffer126 * is aligned on a larger-than-MAXALIGN boundary.  Ideally this should be127 * a platform-dependent value, but for now we just hard-wire it.128 */129#define ALIGNOF_BUFFER	32130 131/*132 * If EXEC_BACKEND is defined, the postmaster uses an alternative method for133 * starting subprocesses: Instead of simply using fork(), as is standard on134 * Unix platforms, it uses fork()+exec() or something equivalent on Windows,135 * as well as lots of extra code to bring the required global state to those136 * new processes.  This must be enabled on Windows (because there is no137 * fork()).  On other platforms, it's only useful for verifying those138 * otherwise Windows-specific code paths.139 */140#if defined(WIN32) && !defined(__CYGWIN__)141#define EXEC_BACKEND142#endif143 144/*145 * USE_POSIX_FADVISE controls whether Postgres will attempt to use the146 * posix_fadvise() kernel call.  Usually the automatic configure tests are147 * sufficient, but some older Linux distributions had broken versions of148 * posix_fadvise().  If necessary you can remove the #define here.149 */150#if HAVE_DECL_POSIX_FADVISE && defined(HAVE_POSIX_FADVISE)151#define USE_POSIX_FADVISE152#endif153 154/*155 * USE_PREFETCH code should be compiled only if we have a way to implement156 * prefetching.  (This is decoupled from USE_POSIX_FADVISE because there157 * might in future be support for alternative low-level prefetch APIs.158 * If you change this, you probably need to adjust the error message in159 * check_effective_io_concurrency.)160 */161#ifdef USE_POSIX_FADVISE162#define USE_PREFETCH163#endif164 165/*166 * Default and maximum values for backend_flush_after, bgwriter_flush_after167 * and checkpoint_flush_after; measured in blocks.  Currently, these are168 * enabled by default if sync_file_range() exists, ie, only on Linux.  Perhaps169 * we could also enable by default if we have mmap and msync(MS_ASYNC)?170 */171#ifdef HAVE_SYNC_FILE_RANGE172#define DEFAULT_BACKEND_FLUSH_AFTER 0	/* never enabled by default */173#define DEFAULT_BGWRITER_FLUSH_AFTER 64174#define DEFAULT_CHECKPOINT_FLUSH_AFTER 32175#else176#define DEFAULT_BACKEND_FLUSH_AFTER 0177#define DEFAULT_BGWRITER_FLUSH_AFTER 0178#define DEFAULT_CHECKPOINT_FLUSH_AFTER 0179#endif180/* upper limit for all three variables */181#define WRITEBACK_MAX_PENDING_FLUSHES 256182 183/*184 * USE_SSL code should be compiled only when compiling with an SSL185 * implementation.186 */187#ifdef USE_OPENSSL188#define USE_SSL189#endif190 191/*192 * This is the default directory in which AF_UNIX socket files are193 * placed.  Caution: changing this risks breaking your existing client194 * applications, which are likely to continue to look in the old195 * directory.  But if you just hate the idea of sockets in /tmp,196 * here's where to twiddle it.  You can also override this at runtime197 * with the postmaster's -k switch.198 *199 * If set to an empty string, then AF_UNIX sockets are not used by default: A200 * server will not create an AF_UNIX socket unless the run-time configuration201 * is changed, a client will connect via TCP/IP by default and will only use202 * an AF_UNIX socket if one is explicitly specified.203 *204 * This is done by default on Windows because there is no good standard205 * location for AF_UNIX sockets and many installations on Windows don't206 * support them yet.207 */208#ifndef WIN32209#define DEFAULT_PGSOCKET_DIR  "/tmp"210#else211#define DEFAULT_PGSOCKET_DIR ""212#endif213 214/*215 * This is the default event source for Windows event log.216 */217#define DEFAULT_EVENT_SOURCE  "PostgreSQL"218 219/*220 * Assumed cache line size. This doesn't affect correctness, but can be used221 * for low-level optimizations. Currently, this is used to pad some data222 * structures in xlog.c, to ensure that highly-contended fields are on223 * different cache lines. Too small a value can hurt performance due to false224 * sharing, while the only downside of too large a value is a few bytes of225 * wasted memory. The default is 128, which should be large enough for all226 * supported platforms.227 */228#define PG_CACHE_LINE_SIZE		128229 230/*231 * Assumed alignment requirement for direct I/O.  4K corresponds to common232 * sector and memory page size.233 */234#define PG_IO_ALIGN_SIZE		4096235 236/*237 *------------------------------------------------------------------------238 * The following symbols are for enabling debugging code, not for239 * controlling user-visible features or resource limits.240 *------------------------------------------------------------------------241 */242 243/*244 * Include Valgrind "client requests", mostly in the memory allocator, so245 * Valgrind understands PostgreSQL memory contexts.  This permits detecting246 * memory errors that Valgrind would not detect on a vanilla build.  It also247 * enables detection of buffer accesses that take place without holding a248 * buffer pin (or without holding a buffer lock in the case of index access249 * methods that superimpose their own custom client requests on top of the250 * generic bufmgr.c requests).251 *252 * "make installcheck" is significantly slower under Valgrind.  The client253 * requests fall in hot code paths, so USE_VALGRIND slows execution by a few254 * percentage points even when not run under Valgrind.255 *256 * Do not try to test the server under Valgrind without having built the257 * server with USE_VALGRIND; else you will get false positives from sinval258 * messaging (see comments in AddCatcacheInvalidationMessage).  It's also259 * important to use the suppression file src/tools/valgrind.supp to260 * exclude other known false positives.261 *262 * You should normally use MEMORY_CONTEXT_CHECKING with USE_VALGRIND;263 * instrumentation of repalloc() is inferior without it.264 */265/* #define USE_VALGRIND */266 267/*268 * Define this to cause pfree()'d memory to be cleared immediately, to269 * facilitate catching bugs that refer to already-freed values.270 * Right now, this gets defined automatically if --enable-cassert.271 */272#ifdef USE_ASSERT_CHECKING273#define CLOBBER_FREED_MEMORY274#endif275 276/*277 * Define this to check memory allocation errors (scribbling on more278 * bytes than were allocated).  Right now, this gets defined279 * automatically if --enable-cassert or USE_VALGRIND.280 */281#if defined(USE_ASSERT_CHECKING) || defined(USE_VALGRIND)282#define MEMORY_CONTEXT_CHECKING283#endif284 285/*286 * Define this to cause palloc()'d memory to be filled with random data, to287 * facilitate catching code that depends on the contents of uninitialized288 * memory.  Caution: this is horrendously expensive.289 */290/* #define RANDOMIZE_ALLOCATED_MEMORY */291 292/*293 * For cache-invalidation debugging, define DISCARD_CACHES_ENABLED to enable294 * use of the debug_discard_caches GUC to aggressively flush syscache/relcache295 * entries whenever it's possible to deliver invalidations.  See296 * AcceptInvalidationMessages() in src/backend/utils/cache/inval.c for297 * details.298 *299 * USE_ASSERT_CHECKING builds default to enabling this.  It's possible to use300 * DISCARD_CACHES_ENABLED without a cassert build and the implied301 * CLOBBER_FREED_MEMORY and MEMORY_CONTEXT_CHECKING options, but it's unlikely302 * to be as effective at identifying problems.303 */304/* #define DISCARD_CACHES_ENABLED */305 306#if defined(USE_ASSERT_CHECKING) && !defined(DISCARD_CACHES_ENABLED)307#define DISCARD_CACHES_ENABLED308#endif309 310/*311 * Backwards compatibility for the older compile-time-only clobber-cache312 * macros.313 */314#if !defined(DISCARD_CACHES_ENABLED) && (defined(CLOBBER_CACHE_ALWAYS) || defined(CLOBBER_CACHE_RECURSIVELY))315#define DISCARD_CACHES_ENABLED316#endif317 318/*319 * Recover memory used for relcache entries when invalidated.  See320 * RelationBuildDesc() in src/backend/utils/cache/relcache.c.321 *322 * This is active automatically for clobber-cache builds when clobbering is323 * active, but can be overridden here by explicitly defining324 * RECOVER_RELATION_BUILD_MEMORY.  Define to 1 to always free relation cache325 * memory even when clobber is off, or to 0 to never free relation cache326 * memory even when clobbering is on.327 */328 /* #define RECOVER_RELATION_BUILD_MEMORY 0 */	/* Force disable */329 /* #define RECOVER_RELATION_BUILD_MEMORY 1 */	/* Force enable */330 331/*332 * Define this to force all parse and plan trees to be passed through333 * copyObject(), to facilitate catching errors and omissions in334 * copyObject().335 */336/* #define COPY_PARSE_PLAN_TREES */337 338/*339 * Define this to force all parse and plan trees to be passed through340 * outfuncs.c/readfuncs.c, to facilitate catching errors and omissions in341 * those modules.342 */343/* #define WRITE_READ_PARSE_PLAN_TREES */344 345/*346 * Define this to force all raw parse trees for DML statements to be scanned347 * by raw_expression_tree_walker(), to facilitate catching errors and348 * omissions in that function.349 */350/* #define RAW_EXPRESSION_COVERAGE_TEST */351 352/*353 * Enable debugging print statements for lock-related operations.354 */355/* #define LOCK_DEBUG */356 357/*358 * Enable debugging print statements for WAL-related operations; see359 * also the wal_debug GUC var.360 */361/* #define WAL_DEBUG */362 363/*364 * Enable tracing of resource consumption during sort operations;365 * see also the trace_sort GUC var.  For 8.1 this is enabled by default.366 */367#define TRACE_SORT 1368 369/*370 * Enable tracing of syncscan operations (see also the trace_syncscan GUC var).371 */372/* #define TRACE_SYNCSCAN */373