src/include/pg_config_manual.h - age - Git at Google

 /*------------------------------------------------------------------------
  * PostgreSQL manual configuration settings
  *
  * This file contains various configuration symbols and limits.  In
  * all cases, changing them is only useful in very rare situations or
  * for developers.  If you edit any of these, be sure to do a *full*
  * rebuild (and an initdb if noted).
  *
  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * src/include/pg_config_manual.h
  *------------------------------------------------------------------------
  */

 /*
  * This is the default value for wal_segment_size to be used when initdb is run
  * without the --wal-segsize option.  It must be a valid segment size.
  */
 #define DEFAULT_XLOG_SEG_SIZE	(16*1024*1024)

 /*
  * Maximum length for identifiers (e.g. table names, column names,
  * function names).  Names actually are limited to one less byte than this,
  * because the length must include a trailing zero byte.
  *
  * Changing this requires an initdb.
  */
 #define NAMEDATALEN 64

 /*
  * Maximum number of arguments to a function.
  *
  * The minimum value is 8 (GIN indexes use 8-argument support functions).
  * The maximum possible value is around 600 (limited by index tuple size in
  * pg_proc's index; BLCKSZ larger than 8K would allow more).  Values larger
  * than needed will waste memory and processing time, but do not directly
  * cost disk space.
  *
  * Changing this does not require an initdb, but it does require a full
  * backend recompile (including any user-defined C functions).
  */
 #define FUNC_MAX_ARGS		100

 /*
  * Maximum number of columns in an index.  There is little point in making
  * this anything but a multiple of 32, because the main cost is associated
  * with index tuple header size (see access/itup.h).
  *
  * Changing this requires an initdb.
  */
 #define INDEX_MAX_KEYS		32

 /*
  * Maximum number of columns in a partition key
  */
 #define PARTITION_MAX_KEYS	32

 /*
  * Decide whether built-in 8-byte types, including float8, int8, and
  * timestamp, are passed by value.  This is on by default if sizeof(Datum) >=
  * 8 (that is, on 64-bit platforms).  If sizeof(Datum) < 8 (32-bit platforms),
  * this must be off.  We keep this here as an option so that it is easy to
  * test the pass-by-reference code paths on 64-bit platforms.
  *
  * Changing this requires an initdb.
  */
 #if SIZEOF_VOID_P >= 8
 #define USE_FLOAT8_BYVAL 1
 #endif

 /*
  * When we don't have native spinlocks, we use semaphores to simulate them.
  * Decreasing this value reduces consumption of OS resources; increasing it
  * may improve performance, but supplying a real spinlock implementation is
  * probably far better.
  */
 #define NUM_SPINLOCK_SEMAPHORES		128

 /*
  * When we have neither spinlocks nor atomic operations support we're
  * implementing atomic operations on top of spinlock on top of semaphores. To
  * be safe against atomic operations while holding a spinlock separate
  * semaphores have to be used.
  */
 #define NUM_ATOMICS_SEMAPHORES		64

 /*
  * MAXPGPATH: standard size of a pathname buffer in PostgreSQL (hence,
  * maximum usable pathname length is one less).
  *
  * We'd use a standard system header symbol for this, if there weren't
  * so many to choose from: MAXPATHLEN, MAX_PATH, PATH_MAX are all
  * defined by different "standards", and often have different values
  * on the same platform!  So we just punt and use a reasonably
  * generous setting here.
  */
 #define MAXPGPATH		1024

 /*
  * PG_SOMAXCONN: maximum accept-queue length limit passed to
  * listen(2).  You'd think we should use SOMAXCONN from
  * <sys/socket.h>, but on many systems that symbol is much smaller
  * than the kernel's actual limit.  In any case, this symbol need be
  * twiddled only if you have a kernel that refuses large limit values,
  * rather than silently reducing the value to what it can handle
  * (which is what most if not all Unixen do).
  */
 #define PG_SOMAXCONN	10000

 /*
  * You can try changing this if you have a machine with bytes of
  * another size, but no guarantee...
  */
 #define BITS_PER_BYTE		8

 /*
  * Preferred alignment for disk I/O buffers.  On some CPUs, copies between
  * user space and kernel space are significantly faster if the user buffer
  * is aligned on a larger-than-MAXALIGN boundary.  Ideally this should be
  * a platform-dependent value, but for now we just hard-wire it.
  */
 #define ALIGNOF_BUFFER	32

 /*
  * If EXEC_BACKEND is defined, the postmaster uses an alternative method for
  * starting subprocesses: Instead of simply using fork(), as is standard on
  * Unix platforms, it uses fork()+exec() or something equivalent on Windows,
  * as well as lots of extra code to bring the required global state to those
  * new processes.  This must be enabled on Windows (because there is no
  * fork()).  On other platforms, it's only useful for verifying those
  * otherwise Windows-specific code paths.
  */
 #if defined(WIN32) && !defined(__CYGWIN__)
 #define EXEC_BACKEND
 #endif

 /*
  * Define this if your operating system supports link()
  */
 #if !defined(WIN32) && !defined(__CYGWIN__)
 #define HAVE_WORKING_LINK 1
 #endif

 /*
  * USE_POSIX_FADVISE controls whether Postgres will attempt to use the
  * posix_fadvise() kernel call.  Usually the automatic configure tests are
  * sufficient, but some older Linux distributions had broken versions of
  * posix_fadvise().  If necessary you can remove the #define here.
  */
 #if HAVE_DECL_POSIX_FADVISE && defined(HAVE_POSIX_FADVISE)
 #define USE_POSIX_FADVISE
 #endif

 /*
  * USE_PREFETCH code should be compiled only if we have a way to implement
  * prefetching.  (This is decoupled from USE_POSIX_FADVISE because there
  * might in future be support for alternative low-level prefetch APIs.
  * If you change this, you probably need to adjust the error message in
  * check_effective_io_concurrency.)
  */
 #ifdef USE_POSIX_FADVISE
 #define USE_PREFETCH
 #endif

 /*
  * Default and maximum values for backend_flush_after, bgwriter_flush_after
  * and checkpoint_flush_after; measured in blocks.  Currently, these are
  * enabled by default if sync_file_range() exists, ie, only on Linux.  Perhaps
  * we could also enable by default if we have mmap and msync(MS_ASYNC)?
  */
 #ifdef HAVE_SYNC_FILE_RANGE
 #define DEFAULT_BACKEND_FLUSH_AFTER 0	/* never enabled by default */
 #define DEFAULT_BGWRITER_FLUSH_AFTER 64
 #define DEFAULT_CHECKPOINT_FLUSH_AFTER 32
 #else
 #define DEFAULT_BACKEND_FLUSH_AFTER 0
 #define DEFAULT_BGWRITER_FLUSH_AFTER 0
 #define DEFAULT_CHECKPOINT_FLUSH_AFTER 0
 #endif
 /* upper limit for all three variables */
 #define WRITEBACK_MAX_PENDING_FLUSHES 256

 /*
  * USE_SSL code should be compiled only when compiling with an SSL
  * implementation.  (Currently, only OpenSSL is supported, but we might add
  * more implementations in the future.)
  */
 #ifdef USE_OPENSSL
 #define USE_SSL
 #endif

 /*
  * This is the default directory in which AF_UNIX socket files are
  * placed.  Caution: changing this risks breaking your existing client
  * applications, which are likely to continue to look in the old
  * directory.  But if you just hate the idea of sockets in /tmp,
  * here's where to twiddle it.  You can also override this at runtime
  * with the postmaster's -k switch.
  *
  * If set to an empty string, then AF_UNIX sockets are not used by default: A
  * server will not create an AF_UNIX socket unless the run-time configuration
  * is changed, a client will connect via TCP/IP by default and will only use
  * an AF_UNIX socket if one is explicitly specified.
  *
  * This is done by default on Windows because there is no good standard
  * location for AF_UNIX sockets and many installations on Windows don't
  * support them yet.
  */
 #ifndef WIN32
 #define DEFAULT_PGSOCKET_DIR  "/tmp"
 #else
 #define DEFAULT_PGSOCKET_DIR ""
 #endif

 /*
  * This is the default event source for Windows event log.
  */
 #define DEFAULT_EVENT_SOURCE  "PostgreSQL"

 /*
  * The random() function is expected to yield values between 0 and
  * MAX_RANDOM_VALUE.  Currently, all known implementations yield
  * 0..2^31-1, so we just hardwire this constant.  We could do a
  * configure test if it proves to be necessary.  CAUTION: Think not to
  * replace this with RAND_MAX.  RAND_MAX defines the maximum value of
  * the older rand() function, which is often different from --- and
  * considerably inferior to --- random().
  */
 #define MAX_RANDOM_VALUE  PG_INT32_MAX

 /*
  * On PPC machines, decide whether to use the mutex hint bit in LWARX
  * instructions.  Setting the hint bit will slightly improve spinlock
  * performance on POWER6 and later machines, but does nothing before that,
  * and will result in illegal-instruction failures on some pre-POWER4
  * machines.  By default we use the hint bit when building for 64-bit PPC,
  * which should be safe in nearly all cases.  You might want to override
  * this if you are building 32-bit code for a known-recent PPC machine.
  */
 #ifdef HAVE_PPC_LWARX_MUTEX_HINT	/* must have assembler support in any case */
 #if defined(__ppc64__) || defined(__powerpc64__)
 #define USE_PPC_LWARX_MUTEX_HINT
 #endif
 #endif

 /*
  * On PPC machines, decide whether to use LWSYNC instructions in place of
  * ISYNC and SYNC.  This provides slightly better performance, but will
  * result in illegal-instruction failures on some pre-POWER4 machines.
  * By default we use LWSYNC when building for 64-bit PPC, which should be
  * safe in nearly all cases.
  */
 #if defined(__ppc64__) || defined(__powerpc64__)
 #define USE_PPC_LWSYNC
 #endif

 /*
  * Assumed cache line size. This doesn't affect correctness, but can be used
  * for low-level optimizations. Currently, this is used to pad some data
  * structures in xlog.c, to ensure that highly-contended fields are on
  * different cache lines. Too small a value can hurt performance due to false
  * sharing, while the only downside of too large a value is a few bytes of
  * wasted memory. The default is 128, which should be large enough for all
  * supported platforms.
  */
 #define PG_CACHE_LINE_SIZE		128

 /*
  *------------------------------------------------------------------------
  * The following symbols are for enabling debugging code, not for
  * controlling user-visible features or resource limits.
  *------------------------------------------------------------------------
  */

 /*
  * Include Valgrind "client requests", mostly in the memory allocator, so
  * Valgrind understands PostgreSQL memory contexts.  This permits detecting
  * memory errors that Valgrind would not detect on a vanilla build.  See also
  * src/tools/valgrind.supp.  "make installcheck" runs 20-30x longer under
  * Valgrind.  Note that USE_VALGRIND slowed older versions of Valgrind by an
  * additional order of magnitude; Valgrind 3.8.1 does not have this problem.
  * The client requests fall in hot code paths, so USE_VALGRIND also slows
  * native execution by a few percentage points.
  *
  * You should normally use MEMORY_CONTEXT_CHECKING with USE_VALGRIND;
  * instrumentation of repalloc() is inferior without it.
  */
 /* #define USE_VALGRIND */

 /*
  * Define this to cause pfree()'d memory to be cleared immediately, to
  * facilitate catching bugs that refer to already-freed values.
  * Right now, this gets defined automatically if --enable-cassert.
  */
 #ifdef USE_ASSERT_CHECKING
 #define CLOBBER_FREED_MEMORY
 #endif

 /*
  * Define this to check memory allocation errors (scribbling on more
  * bytes than were allocated).  Right now, this gets defined
  * automatically if --enable-cassert or USE_VALGRIND.
  */
 #if defined(USE_ASSERT_CHECKING) || defined(USE_VALGRIND)
 #define MEMORY_CONTEXT_CHECKING
 #endif

 /*
  * Define this to cause palloc()'d memory to be filled with random data, to
  * facilitate catching code that depends on the contents of uninitialized
  * memory.  Caution: this is horrendously expensive.
  */
 /* #define RANDOMIZE_ALLOCATED_MEMORY */

 /*
  * Define this to force all parse and plan trees to be passed through
  * copyObject(), to facilitate catching errors and omissions in
  * copyObject().
  */
 /* #define COPY_PARSE_PLAN_TREES */

 /*
  * Define this to force all parse and plan trees to be passed through
  * outfuncs.c/readfuncs.c, to facilitate catching errors and omissions in
  * those modules.
  */
 /* #define WRITE_READ_PARSE_PLAN_TREES */

 /*
  * Define this to force all raw parse trees for DML statements to be scanned
  * by raw_expression_tree_walker(), to facilitate catching errors and
  * omissions in that function.
  */
 /* #define RAW_EXPRESSION_COVERAGE_TEST */

 /*
  * Enable debugging print statements for lock-related operations.
  */
 /* #define LOCK_DEBUG */

 /*
  * Enable debugging print statements for WAL-related operations; see
  * also the wal_debug GUC var.
  */
 /* #define WAL_DEBUG */

 /*
  * Enable tracing of resource consumption during sort operations;
  * see also the trace_sort GUC var.  For 8.1 this is enabled by default.
  */
 #define TRACE_SORT 1

 /*
  * Enable tracing of syncscan operations (see also the trace_syncscan GUC var).
  */
 /* #define TRACE_SYNCSCAN */
	/*------------------------------------------------------------------------
	* PostgreSQL manual configuration settings
	*
	* This file contains various configuration symbols and limits. In
	* all cases, changing them is only useful in very rare situations or
	* for developers. If you edit any of these, be sure to do a full
	* rebuild (and an initdb if noted).
	*
	* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
	* Portions Copyright (c) 1994, Regents of the University of California
	*
	* src/include/pg_config_manual.h
	*------------------------------------------------------------------------
	*/

	/*
	* This is the default value for wal_segment_size to be used when initdb is run
	* without the --wal-segsize option. It must be a valid segment size.
	*/
	#define DEFAULT_XLOG_SEG_SIZE (1610241024)

	/*
	* Maximum length for identifiers (e.g. table names, column names,
	* function names). Names actually are limited to one less byte than this,
	* because the length must include a trailing zero byte.
	*
	* Changing this requires an initdb.
	*/
	#define NAMEDATALEN 64

	/*
	* Maximum number of arguments to a function.
	*
	* The minimum value is 8 (GIN indexes use 8-argument support functions).
	* The maximum possible value is around 600 (limited by index tuple size in
	* pg_proc's index; BLCKSZ larger than 8K would allow more). Values larger
	* than needed will waste memory and processing time, but do not directly
	* cost disk space.
	*
	* Changing this does not require an initdb, but it does require a full
	* backend recompile (including any user-defined C functions).
	*/
	#define FUNC_MAX_ARGS 100

	/*
	* Maximum number of columns in an index. There is little point in making
	* this anything but a multiple of 32, because the main cost is associated
	* with index tuple header size (see access/itup.h).
	*
	* Changing this requires an initdb.
	*/
	#define INDEX_MAX_KEYS 32

	/*
	* Maximum number of columns in a partition key
	*/
	#define PARTITION_MAX_KEYS 32

	/*
	* Decide whether built-in 8-byte types, including float8, int8, and
	* timestamp, are passed by value. This is on by default if sizeof(Datum) >=
	* 8 (that is, on 64-bit platforms). If sizeof(Datum) < 8 (32-bit platforms),
	* this must be off. We keep this here as an option so that it is easy to
	* test the pass-by-reference code paths on 64-bit platforms.
	*
	* Changing this requires an initdb.
	*/
	#if SIZEOF_VOID_P >= 8
	#define USE_FLOAT8_BYVAL 1
	#endif

	/*
	* When we don't have native spinlocks, we use semaphores to simulate them.
	* Decreasing this value reduces consumption of OS resources; increasing it
	* may improve performance, but supplying a real spinlock implementation is
	* probably far better.
	*/
	#define NUM_SPINLOCK_SEMAPHORES 128

	/*
	* When we have neither spinlocks nor atomic operations support we're
	* implementing atomic operations on top of spinlock on top of semaphores. To
	* be safe against atomic operations while holding a spinlock separate
	* semaphores have to be used.
	*/
	#define NUM_ATOMICS_SEMAPHORES 64

	/*
	* MAXPGPATH: standard size of a pathname buffer in PostgreSQL (hence,
	* maximum usable pathname length is one less).
	*
	* We'd use a standard system header symbol for this, if there weren't
	* so many to choose from: MAXPATHLEN, MAX_PATH, PATH_MAX are all
	* defined by different "standards", and often have different values
	* on the same platform! So we just punt and use a reasonably
	* generous setting here.
	*/
	#define MAXPGPATH 1024

	/*
	* PG_SOMAXCONN: maximum accept-queue length limit passed to
	* listen(2). You'd think we should use SOMAXCONN from
	* <sys/socket.h>, but on many systems that symbol is much smaller
	* than the kernel's actual limit. In any case, this symbol need be
	* twiddled only if you have a kernel that refuses large limit values,
	* rather than silently reducing the value to what it can handle
	* (which is what most if not all Unixen do).
	*/
	#define PG_SOMAXCONN 10000

	/*
	* You can try changing this if you have a machine with bytes of
	* another size, but no guarantee...
	*/
	#define BITS_PER_BYTE 8

	/*
	* Preferred alignment for disk I/O buffers. On some CPUs, copies between
	* user space and kernel space are significantly faster if the user buffer
	* is aligned on a larger-than-MAXALIGN boundary. Ideally this should be
	* a platform-dependent value, but for now we just hard-wire it.
	*/
	#define ALIGNOF_BUFFER 32

	/*
	* If EXEC_BACKEND is defined, the postmaster uses an alternative method for
	* starting subprocesses: Instead of simply using fork(), as is standard on
	* Unix platforms, it uses fork()+exec() or something equivalent on Windows,
	* as well as lots of extra code to bring the required global state to those
	* new processes. This must be enabled on Windows (because there is no
	* fork()). On other platforms, it's only useful for verifying those
	* otherwise Windows-specific code paths.
	*/
	#if defined(WIN32) && !defined(__CYGWIN__)
	#define EXEC_BACKEND
	#endif

	/*
	* Define this if your operating system supports link()
	*/
	#if !defined(WIN32) && !defined(__CYGWIN__)
	#define HAVE_WORKING_LINK 1
	#endif

	/*
	* USE_POSIX_FADVISE controls whether Postgres will attempt to use the
	* posix_fadvise() kernel call. Usually the automatic configure tests are
	* sufficient, but some older Linux distributions had broken versions of
	* posix_fadvise(). If necessary you can remove the #define here.
	*/
	#if HAVE_DECL_POSIX_FADVISE && defined(HAVE_POSIX_FADVISE)
	#define USE_POSIX_FADVISE
	#endif

	/*
	* USE_PREFETCH code should be compiled only if we have a way to implement
	* prefetching. (This is decoupled from USE_POSIX_FADVISE because there
	* might in future be support for alternative low-level prefetch APIs.
	* If you change this, you probably need to adjust the error message in
	* check_effective_io_concurrency.)
	*/
	#ifdef USE_POSIX_FADVISE
	#define USE_PREFETCH
	#endif

	/*
	* Default and maximum values for backend_flush_after, bgwriter_flush_after
	* and checkpoint_flush_after; measured in blocks. Currently, these are
	* enabled by default if sync_file_range() exists, ie, only on Linux. Perhaps
	* we could also enable by default if we have mmap and msync(MS_ASYNC)?
	*/
	#ifdef HAVE_SYNC_FILE_RANGE
	#define DEFAULT_BACKEND_FLUSH_AFTER 0 /* never enabled by default */
	#define DEFAULT_BGWRITER_FLUSH_AFTER 64
	#define DEFAULT_CHECKPOINT_FLUSH_AFTER 32
	#else
	#define DEFAULT_BACKEND_FLUSH_AFTER 0
	#define DEFAULT_BGWRITER_FLUSH_AFTER 0
	#define DEFAULT_CHECKPOINT_FLUSH_AFTER 0
	#endif
	/* upper limit for all three variables */
	#define WRITEBACK_MAX_PENDING_FLUSHES 256

	/*
	* USE_SSL code should be compiled only when compiling with an SSL
	* implementation. (Currently, only OpenSSL is supported, but we might add
	* more implementations in the future.)
	*/
	#ifdef USE_OPENSSL
	#define USE_SSL
	#endif

	/*
	* This is the default directory in which AF_UNIX socket files are
	* placed. Caution: changing this risks breaking your existing client
	* applications, which are likely to continue to look in the old
	* directory. But if you just hate the idea of sockets in /tmp,
	* here's where to twiddle it. You can also override this at runtime
	* with the postmaster's -k switch.
	*
	* If set to an empty string, then AF_UNIX sockets are not used by default: A
	* server will not create an AF_UNIX socket unless the run-time configuration
	* is changed, a client will connect via TCP/IP by default and will only use
	* an AF_UNIX socket if one is explicitly specified.
	*
	* This is done by default on Windows because there is no good standard
	* location for AF_UNIX sockets and many installations on Windows don't
	* support them yet.
	*/
	#ifndef WIN32
	#define DEFAULT_PGSOCKET_DIR "/tmp"
	#else
	#define DEFAULT_PGSOCKET_DIR ""
	#endif

	/*
	* This is the default event source for Windows event log.
	*/
	#define DEFAULT_EVENT_SOURCE "PostgreSQL"

	/*
	* The random() function is expected to yield values between 0 and
	* MAX_RANDOM_VALUE. Currently, all known implementations yield
	* 0..2^31-1, so we just hardwire this constant. We could do a
	* configure test if it proves to be necessary. CAUTION: Think not to
	* replace this with RAND_MAX. RAND_MAX defines the maximum value of
	* the older rand() function, which is often different from --- and
	* considerably inferior to --- random().
	*/
	#define MAX_RANDOM_VALUE PG_INT32_MAX

	/*
	* On PPC machines, decide whether to use the mutex hint bit in LWARX
	* instructions. Setting the hint bit will slightly improve spinlock
	* performance on POWER6 and later machines, but does nothing before that,
	* and will result in illegal-instruction failures on some pre-POWER4
	* machines. By default we use the hint bit when building for 64-bit PPC,
	* which should be safe in nearly all cases. You might want to override
	* this if you are building 32-bit code for a known-recent PPC machine.
	*/
	#ifdef HAVE_PPC_LWARX_MUTEX_HINT /* must have assembler support in any case */
	#if defined(__ppc64__) \|\| defined(__powerpc64__)
	#define USE_PPC_LWARX_MUTEX_HINT
	#endif
	#endif

	/*
	* On PPC machines, decide whether to use LWSYNC instructions in place of
	* ISYNC and SYNC. This provides slightly better performance, but will
	* result in illegal-instruction failures on some pre-POWER4 machines.
	* By default we use LWSYNC when building for 64-bit PPC, which should be
	* safe in nearly all cases.
	*/
	#if defined(__ppc64__) \|\| defined(__powerpc64__)
	#define USE_PPC_LWSYNC
	#endif

	/*
	* Assumed cache line size. This doesn't affect correctness, but can be used
	* for low-level optimizations. Currently, this is used to pad some data
	* structures in xlog.c, to ensure that highly-contended fields are on
	* different cache lines. Too small a value can hurt performance due to false
	* sharing, while the only downside of too large a value is a few bytes of
	* wasted memory. The default is 128, which should be large enough for all
	* supported platforms.
	*/
	#define PG_CACHE_LINE_SIZE 128

	/*
	*------------------------------------------------------------------------
	* The following symbols are for enabling debugging code, not for
	* controlling user-visible features or resource limits.
	*------------------------------------------------------------------------
	*/

	/*
	* Include Valgrind "client requests", mostly in the memory allocator, so
	* Valgrind understands PostgreSQL memory contexts. This permits detecting
	* memory errors that Valgrind would not detect on a vanilla build. See also
	* src/tools/valgrind.supp. "make installcheck" runs 20-30x longer under
	* Valgrind. Note that USE_VALGRIND slowed older versions of Valgrind by an
	* additional order of magnitude; Valgrind 3.8.1 does not have this problem.
	* The client requests fall in hot code paths, so USE_VALGRIND also slows
	* native execution by a few percentage points.
	*
	* You should normally use MEMORY_CONTEXT_CHECKING with USE_VALGRIND;
	* instrumentation of repalloc() is inferior without it.
	*/
	/* #define USE_VALGRIND */

	/*
	* Define this to cause pfree()'d memory to be cleared immediately, to
	* facilitate catching bugs that refer to already-freed values.
	* Right now, this gets defined automatically if --enable-cassert.
	*/
	#ifdef USE_ASSERT_CHECKING
	#define CLOBBER_FREED_MEMORY
	#endif

	/*
	* Define this to check memory allocation errors (scribbling on more
	* bytes than were allocated). Right now, this gets defined
	* automatically if --enable-cassert or USE_VALGRIND.
	*/
	#if defined(USE_ASSERT_CHECKING) \|\| defined(USE_VALGRIND)
	#define MEMORY_CONTEXT_CHECKING
	#endif

	/*
	* Define this to cause palloc()'d memory to be filled with random data, to
	* facilitate catching code that depends on the contents of uninitialized
	* memory. Caution: this is horrendously expensive.
	*/
	/* #define RANDOMIZE_ALLOCATED_MEMORY */

	/*
	* Define this to force all parse and plan trees to be passed through
	* copyObject(), to facilitate catching errors and omissions in
	* copyObject().
	*/
	/* #define COPY_PARSE_PLAN_TREES */

	/*
	* Define this to force all parse and plan trees to be passed through
	* outfuncs.c/readfuncs.c, to facilitate catching errors and omissions in
	* those modules.
	*/
	/* #define WRITE_READ_PARSE_PLAN_TREES */

	/*
	* Define this to force all raw parse trees for DML statements to be scanned
	* by raw_expression_tree_walker(), to facilitate catching errors and
	* omissions in that function.
	*/
	/* #define RAW_EXPRESSION_COVERAGE_TEST */

	/*
	* Enable debugging print statements for lock-related operations.
	*/
	/* #define LOCK_DEBUG */

	/*
	* Enable debugging print statements for WAL-related operations; see
	* also the wal_debug GUC var.
	*/
	/* #define WAL_DEBUG */

	/*
	* Enable tracing of resource consumption during sort operations;
	* see also the trace_sort GUC var. For 8.1 this is enabled by default.
	*/
	#define TRACE_SORT 1

	/*
	* Enable tracing of syncscan operations (see also the trace_syncscan GUC var).
	*/
	/* #define TRACE_SYNCSCAN */