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pg_stat_statements.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pg_stat_statements.c
4  * Track statement planning and execution times as well as resource
5  * usage across a whole database cluster.
6  *
7  * Execution costs are totaled for each distinct source query, and kept in
8  * a shared hashtable. (We track only as many distinct queries as will fit
9  * in the designated amount of shared memory.)
10  *
11  * Starting in Postgres 9.2, this module normalized query entries. As of
12  * Postgres 14, the normalization is done by the core if compute_query_id is
13  * enabled, or optionally by third-party modules.
14  *
15  * To facilitate presenting entries to users, we create "representative" query
16  * strings in which constants are replaced with parameter symbols ($n), to
17  * make it clearer what a normalized entry can represent. To save on shared
18  * memory, and to avoid having to truncate oversized query strings, we store
19  * these strings in a temporary external query-texts file. Offsets into this
20  * file are kept in shared memory.
21  *
22  * Note about locking issues: to create or delete an entry in the shared
23  * hashtable, one must hold pgss->lock exclusively. Modifying any field
24  * in an entry except the counters requires the same. To look up an entry,
25  * one must hold the lock shared. To read or update the counters within
26  * an entry, one must hold the lock shared or exclusive (so the entry doesn't
27  * disappear!) and also take the entry's mutex spinlock.
28  * The shared state variable pgss->extent (the next free spot in the external
29  * query-text file) should be accessed only while holding either the
30  * pgss->mutex spinlock, or exclusive lock on pgss->lock. We use the mutex to
31  * allow reserving file space while holding only shared lock on pgss->lock.
32  * Rewriting the entire external query-text file, eg for garbage collection,
33  * requires holding pgss->lock exclusively; this allows individual entries
34  * in the file to be read or written while holding only shared lock.
35  *
36  *
37  * Copyright (c) 2008-2023, PostgreSQL Global Development Group
38  *
39  * IDENTIFICATION
40  * contrib/pg_stat_statements/pg_stat_statements.c
41  *
42  *-------------------------------------------------------------------------
43  */
44 #include "postgres.h"
45 
46 #include <math.h>
47 #include <sys/stat.h>
48 #include <unistd.h>
49 
50 #include "access/parallel.h"
51 #include "catalog/pg_authid.h"
52 #include "common/hashfn.h"
53 #include "executor/instrument.h"
54 #include "funcapi.h"
55 #include "jit/jit.h"
56 #include "mb/pg_wchar.h"
57 #include "miscadmin.h"
58 #include "nodes/queryjumble.h"
59 #include "optimizer/planner.h"
60 #include "parser/analyze.h"
61 #include "parser/parsetree.h"
62 #include "parser/scanner.h"
63 #include "parser/scansup.h"
64 #include "pgstat.h"
65 #include "storage/fd.h"
66 #include "storage/ipc.h"
67 #include "storage/lwlock.h"
68 #include "storage/shmem.h"
69 #include "storage/spin.h"
70 #include "tcop/utility.h"
71 #include "utils/acl.h"
72 #include "utils/builtins.h"
73 #include "utils/memutils.h"
74 #include "utils/timestamp.h"
75 
77 
78 /* Location of permanent stats file (valid when database is shut down) */
79 #define PGSS_DUMP_FILE PGSTAT_STAT_PERMANENT_DIRECTORY "/pg_stat_statements.stat"
80 
81 /*
82  * Location of external query text file.
83  */
84 #define PGSS_TEXT_FILE PG_STAT_TMP_DIR "/pgss_query_texts.stat"
85 
86 /* Magic number identifying the stats file format */
87 static const uint32 PGSS_FILE_HEADER = 0x20220408;
88 
89 /* PostgreSQL major version number, changes in which invalidate all entries */
90 static const uint32 PGSS_PG_MAJOR_VERSION = PG_VERSION_NUM / 100;
91 
92 /* XXX: Should USAGE_EXEC reflect execution time and/or buffer usage? */
93 #define USAGE_EXEC(duration) (1.0)
94 #define USAGE_INIT (1.0) /* including initial planning */
95 #define ASSUMED_MEDIAN_INIT (10.0) /* initial assumed median usage */
96 #define ASSUMED_LENGTH_INIT 1024 /* initial assumed mean query length */
97 #define USAGE_DECREASE_FACTOR (0.99) /* decreased every entry_dealloc */
98 #define STICKY_DECREASE_FACTOR (0.50) /* factor for sticky entries */
99 #define USAGE_DEALLOC_PERCENT 5 /* free this % of entries at once */
100 #define IS_STICKY(c) ((c.calls[PGSS_PLAN] + c.calls[PGSS_EXEC]) == 0)
101 
102 /*
103  * Utility statements that pgss_ProcessUtility and pgss_post_parse_analyze
104  * ignores.
105  */
106 #define PGSS_HANDLED_UTILITY(n) (!IsA(n, ExecuteStmt) && \
107  !IsA(n, PrepareStmt) && \
108  !IsA(n, DeallocateStmt))
109 
110 /*
111  * Extension version number, for supporting older extension versions' objects
112  */
113 typedef enum pgssVersion
114 {
121  PGSS_V1_10
123 
124 typedef enum pgssStoreKind
125 {
127 
128  /*
129  * PGSS_PLAN and PGSS_EXEC must be respectively 0 and 1 as they're used to
130  * reference the underlying values in the arrays in the Counters struct,
131  * and this order is required in pg_stat_statements_internal().
132  */
135 
136  PGSS_NUMKIND /* Must be last value of this enum */
138 
139 /*
140  * Hashtable key that defines the identity of a hashtable entry. We separate
141  * queries by user and by database even if they are otherwise identical.
142  *
143  * If you add a new key to this struct, make sure to teach pgss_store() to
144  * zero the padding bytes. Otherwise, things will break, because pgss_hash is
145  * created using HASH_BLOBS, and thus tag_hash is used to hash this.
146 
147  */
148 typedef struct pgssHashKey
149 {
150  Oid userid; /* user OID */
151  Oid dbid; /* database OID */
152  uint64 queryid; /* query identifier */
153  bool toplevel; /* query executed at top level */
155 
156 /*
157  * The actual stats counters kept within pgssEntry.
158  */
159 typedef struct Counters
160 {
161  int64 calls[PGSS_NUMKIND]; /* # of times planned/executed */
162  double total_time[PGSS_NUMKIND]; /* total planning/execution time,
163  * in msec */
164  double min_time[PGSS_NUMKIND]; /* minimum planning/execution time in
165  * msec */
166  double max_time[PGSS_NUMKIND]; /* maximum planning/execution time in
167  * msec */
168  double mean_time[PGSS_NUMKIND]; /* mean planning/execution time in
169  * msec */
170  double sum_var_time[PGSS_NUMKIND]; /* sum of variances in
171  * planning/execution time in msec */
172  int64 rows; /* total # of retrieved or affected rows */
173  int64 shared_blks_hit; /* # of shared buffer hits */
174  int64 shared_blks_read; /* # of shared disk blocks read */
175  int64 shared_blks_dirtied; /* # of shared disk blocks dirtied */
176  int64 shared_blks_written; /* # of shared disk blocks written */
177  int64 local_blks_hit; /* # of local buffer hits */
178  int64 local_blks_read; /* # of local disk blocks read */
179  int64 local_blks_dirtied; /* # of local disk blocks dirtied */
180  int64 local_blks_written; /* # of local disk blocks written */
181  int64 temp_blks_read; /* # of temp blocks read */
182  int64 temp_blks_written; /* # of temp blocks written */
183  double blk_read_time; /* time spent reading blocks, in msec */
184  double blk_write_time; /* time spent writing blocks, in msec */
185  double temp_blk_read_time; /* time spent reading temp blocks, in msec */
186  double temp_blk_write_time; /* time spent writing temp blocks, in
187  * msec */
188  double usage; /* usage factor */
189  int64 wal_records; /* # of WAL records generated */
190  int64 wal_fpi; /* # of WAL full page images generated */
191  uint64 wal_bytes; /* total amount of WAL generated in bytes */
192  int64 jit_functions; /* total number of JIT functions emitted */
193  double jit_generation_time; /* total time to generate jit code */
194  int64 jit_inlining_count; /* number of times inlining time has been
195  * > 0 */
196  double jit_inlining_time; /* total time to inline jit code */
197  int64 jit_optimization_count; /* number of times optimization time
198  * has been > 0 */
199  double jit_optimization_time; /* total time to optimize jit code */
200  int64 jit_emission_count; /* number of times emission time has been
201  * > 0 */
202  double jit_emission_time; /* total time to emit jit code */
204 
205 /*
206  * Global statistics for pg_stat_statements
207  */
208 typedef struct pgssGlobalStats
209 {
210  int64 dealloc; /* # of times entries were deallocated */
211  TimestampTz stats_reset; /* timestamp with all stats reset */
213 
214 /*
215  * Statistics per statement
216  *
217  * Note: in event of a failure in garbage collection of the query text file,
218  * we reset query_offset to zero and query_len to -1. This will be seen as
219  * an invalid state by qtext_fetch().
220  */
221 typedef struct pgssEntry
222 {
223  pgssHashKey key; /* hash key of entry - MUST BE FIRST */
224  Counters counters; /* the statistics for this query */
225  Size query_offset; /* query text offset in external file */
226  int query_len; /* # of valid bytes in query string, or -1 */
227  int encoding; /* query text encoding */
228  slock_t mutex; /* protects the counters only */
230 
231 /*
232  * Global shared state
233  */
234 typedef struct pgssSharedState
235 {
236  LWLock *lock; /* protects hashtable search/modification */
237  double cur_median_usage; /* current median usage in hashtable */
238  Size mean_query_len; /* current mean entry text length */
239  slock_t mutex; /* protects following fields only: */
240  Size extent; /* current extent of query file */
241  int n_writers; /* number of active writers to query file */
242  int gc_count; /* query file garbage collection cycle count */
243  pgssGlobalStats stats; /* global statistics for pgss */
245 
246 /*---- Local variables ----*/
247 
248 /* Current nesting depth of ExecutorRun+ProcessUtility calls */
249 static int exec_nested_level = 0;
250 
251 /* Current nesting depth of planner calls */
252 static int plan_nested_level = 0;
253 
254 /* Saved hook values in case of unload */
264 
265 /* Links to shared memory state */
266 static pgssSharedState *pgss = NULL;
267 static HTAB *pgss_hash = NULL;
268 
269 /*---- GUC variables ----*/
270 
271 typedef enum
272 {
273  PGSS_TRACK_NONE, /* track no statements */
274  PGSS_TRACK_TOP, /* only top level statements */
275  PGSS_TRACK_ALL /* all statements, including nested ones */
277 
278 static const struct config_enum_entry track_options[] =
279 {
280  {"none", PGSS_TRACK_NONE, false},
281  {"top", PGSS_TRACK_TOP, false},
282  {"all", PGSS_TRACK_ALL, false},
283  {NULL, 0, false}
284 };
285 
286 static int pgss_max = 5000; /* max # statements to track */
287 static int pgss_track = PGSS_TRACK_TOP; /* tracking level */
288 static bool pgss_track_utility = true; /* whether to track utility commands */
289 static bool pgss_track_planning = false; /* whether to track planning
290  * duration */
291 static bool pgss_save = true; /* whether to save stats across shutdown */
292 
293 
294 #define pgss_enabled(level) \
295  (!IsParallelWorker() && \
296  (pgss_track == PGSS_TRACK_ALL || \
297  (pgss_track == PGSS_TRACK_TOP && (level) == 0)))
298 
299 #define record_gc_qtexts() \
300  do { \
301  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss; \
302  SpinLockAcquire(&s->mutex); \
303  s->gc_count++; \
304  SpinLockRelease(&s->mutex); \
305  } while(0)
306 
307 /*---- Function declarations ----*/
308 
318 
319 static void pgss_shmem_request(void);
320 static void pgss_shmem_startup(void);
321 static void pgss_shmem_shutdown(int code, Datum arg);
322 static void pgss_post_parse_analyze(ParseState *pstate, Query *query,
323  JumbleState *jstate);
325  const char *query_string,
326  int cursorOptions,
327  ParamListInfo boundParams);
328 static void pgss_ExecutorStart(QueryDesc *queryDesc, int eflags);
329 static void pgss_ExecutorRun(QueryDesc *queryDesc,
330  ScanDirection direction,
331  uint64 count, bool execute_once);
332 static void pgss_ExecutorFinish(QueryDesc *queryDesc);
333 static void pgss_ExecutorEnd(QueryDesc *queryDesc);
334 static void pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
335  bool readOnlyTree,
336  ProcessUtilityContext context, ParamListInfo params,
337  QueryEnvironment *queryEnv,
339 static void pgss_store(const char *query, uint64 queryId,
340  int query_location, int query_len,
341  pgssStoreKind kind,
342  double total_time, uint64 rows,
343  const BufferUsage *bufusage,
344  const WalUsage *walusage,
345  const struct JitInstrumentation *jitusage,
346  JumbleState *jstate);
348  pgssVersion api_version,
349  bool showtext);
350 static Size pgss_memsize(void);
351 static pgssEntry *entry_alloc(pgssHashKey *key, Size query_offset, int query_len,
352  int encoding, bool sticky);
353 static void entry_dealloc(void);
354 static bool qtext_store(const char *query, int query_len,
355  Size *query_offset, int *gc_count);
356 static char *qtext_load_file(Size *buffer_size);
357 static char *qtext_fetch(Size query_offset, int query_len,
358  char *buffer, Size buffer_size);
359 static bool need_gc_qtexts(void);
360 static void gc_qtexts(void);
361 static void entry_reset(Oid userid, Oid dbid, uint64 queryid);
362 static char *generate_normalized_query(JumbleState *jstate, const char *query,
363  int query_loc, int *query_len_p);
364 static void fill_in_constant_lengths(JumbleState *jstate, const char *query,
365  int query_loc);
366 static int comp_location(const void *a, const void *b);
367 
368 
369 /*
370  * Module load callback
371  */
372 void
373 _PG_init(void)
374 {
375  /*
376  * In order to create our shared memory area, we have to be loaded via
377  * shared_preload_libraries. If not, fall out without hooking into any of
378  * the main system. (We don't throw error here because it seems useful to
379  * allow the pg_stat_statements functions to be created even when the
380  * module isn't active. The functions must protect themselves against
381  * being called then, however.)
382  */
384  return;
385 
386  /*
387  * Inform the postmaster that we want to enable query_id calculation if
388  * compute_query_id is set to auto.
389  */
390  EnableQueryId();
391 
392  /*
393  * Define (or redefine) custom GUC variables.
394  */
395  DefineCustomIntVariable("pg_stat_statements.max",
396  "Sets the maximum number of statements tracked by pg_stat_statements.",
397  NULL,
398  &pgss_max,
399  5000,
400  100,
401  INT_MAX / 2,
403  0,
404  NULL,
405  NULL,
406  NULL);
407 
408  DefineCustomEnumVariable("pg_stat_statements.track",
409  "Selects which statements are tracked by pg_stat_statements.",
410  NULL,
411  &pgss_track,
414  PGC_SUSET,
415  0,
416  NULL,
417  NULL,
418  NULL);
419 
420  DefineCustomBoolVariable("pg_stat_statements.track_utility",
421  "Selects whether utility commands are tracked by pg_stat_statements.",
422  NULL,
424  true,
425  PGC_SUSET,
426  0,
427  NULL,
428  NULL,
429  NULL);
430 
431  DefineCustomBoolVariable("pg_stat_statements.track_planning",
432  "Selects whether planning duration is tracked by pg_stat_statements.",
433  NULL,
435  false,
436  PGC_SUSET,
437  0,
438  NULL,
439  NULL,
440  NULL);
441 
442  DefineCustomBoolVariable("pg_stat_statements.save",
443  "Save pg_stat_statements statistics across server shutdowns.",
444  NULL,
445  &pgss_save,
446  true,
447  PGC_SIGHUP,
448  0,
449  NULL,
450  NULL,
451  NULL);
452 
453  MarkGUCPrefixReserved("pg_stat_statements");
454 
455  /*
456  * Install hooks.
457  */
476 }
477 
478 /*
479  * shmem_request hook: request additional shared resources. We'll allocate or
480  * attach to the shared resources in pgss_shmem_startup().
481  */
482 static void
484 {
487 
489  RequestNamedLWLockTranche("pg_stat_statements", 1);
490 }
491 
492 /*
493  * shmem_startup hook: allocate or attach to shared memory,
494  * then load any pre-existing statistics from file.
495  * Also create and load the query-texts file, which is expected to exist
496  * (even if empty) while the module is enabled.
497  */
498 static void
500 {
501  bool found;
502  HASHCTL info;
503  FILE *file = NULL;
504  FILE *qfile = NULL;
505  uint32 header;
506  int32 num;
507  int32 pgver;
508  int32 i;
509  int buffer_size;
510  char *buffer = NULL;
511 
514 
515  /* reset in case this is a restart within the postmaster */
516  pgss = NULL;
517  pgss_hash = NULL;
518 
519  /*
520  * Create or attach to the shared memory state, including hash table
521  */
522  LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
523 
524  pgss = ShmemInitStruct("pg_stat_statements",
525  sizeof(pgssSharedState),
526  &found);
527 
528  if (!found)
529  {
530  /* First time through ... */
531  pgss->lock = &(GetNamedLWLockTranche("pg_stat_statements"))->lock;
535  pgss->extent = 0;
536  pgss->n_writers = 0;
537  pgss->gc_count = 0;
538  pgss->stats.dealloc = 0;
540  }
541 
542  info.keysize = sizeof(pgssHashKey);
543  info.entrysize = sizeof(pgssEntry);
544  pgss_hash = ShmemInitHash("pg_stat_statements hash",
546  &info,
548 
549  LWLockRelease(AddinShmemInitLock);
550 
551  /*
552  * If we're in the postmaster (or a standalone backend...), set up a shmem
553  * exit hook to dump the statistics to disk.
554  */
555  if (!IsUnderPostmaster)
557 
558  /*
559  * Done if some other process already completed our initialization.
560  */
561  if (found)
562  return;
563 
564  /*
565  * Note: we don't bother with locks here, because there should be no other
566  * processes running when this code is reached.
567  */
568 
569  /* Unlink query text file possibly left over from crash */
570  unlink(PGSS_TEXT_FILE);
571 
572  /* Allocate new query text temp file */
574  if (qfile == NULL)
575  goto write_error;
576 
577  /*
578  * If we were told not to load old statistics, we're done. (Note we do
579  * not try to unlink any old dump file in this case. This seems a bit
580  * questionable but it's the historical behavior.)
581  */
582  if (!pgss_save)
583  {
584  FreeFile(qfile);
585  return;
586  }
587 
588  /*
589  * Attempt to load old statistics from the dump file.
590  */
592  if (file == NULL)
593  {
594  if (errno != ENOENT)
595  goto read_error;
596  /* No existing persisted stats file, so we're done */
597  FreeFile(qfile);
598  return;
599  }
600 
601  buffer_size = 2048;
602  buffer = (char *) palloc(buffer_size);
603 
604  if (fread(&header, sizeof(uint32), 1, file) != 1 ||
605  fread(&pgver, sizeof(uint32), 1, file) != 1 ||
606  fread(&num, sizeof(int32), 1, file) != 1)
607  goto read_error;
608 
609  if (header != PGSS_FILE_HEADER ||
610  pgver != PGSS_PG_MAJOR_VERSION)
611  goto data_error;
612 
613  for (i = 0; i < num; i++)
614  {
615  pgssEntry temp;
616  pgssEntry *entry;
617  Size query_offset;
618 
619  if (fread(&temp, sizeof(pgssEntry), 1, file) != 1)
620  goto read_error;
621 
622  /* Encoding is the only field we can easily sanity-check */
623  if (!PG_VALID_BE_ENCODING(temp.encoding))
624  goto data_error;
625 
626  /* Resize buffer as needed */
627  if (temp.query_len >= buffer_size)
628  {
629  buffer_size = Max(buffer_size * 2, temp.query_len + 1);
630  buffer = repalloc(buffer, buffer_size);
631  }
632 
633  if (fread(buffer, 1, temp.query_len + 1, file) != temp.query_len + 1)
634  goto read_error;
635 
636  /* Should have a trailing null, but let's make sure */
637  buffer[temp.query_len] = '\0';
638 
639  /* Skip loading "sticky" entries */
640  if (IS_STICKY(temp.counters))
641  continue;
642 
643  /* Store the query text */
644  query_offset = pgss->extent;
645  if (fwrite(buffer, 1, temp.query_len + 1, qfile) != temp.query_len + 1)
646  goto write_error;
647  pgss->extent += temp.query_len + 1;
648 
649  /* make the hashtable entry (discards old entries if too many) */
650  entry = entry_alloc(&temp.key, query_offset, temp.query_len,
651  temp.encoding,
652  false);
653 
654  /* copy in the actual stats */
655  entry->counters = temp.counters;
656  }
657 
658  /* Read global statistics for pg_stat_statements */
659  if (fread(&pgss->stats, sizeof(pgssGlobalStats), 1, file) != 1)
660  goto read_error;
661 
662  pfree(buffer);
663  FreeFile(file);
664  FreeFile(qfile);
665 
666  /*
667  * Remove the persisted stats file so it's not included in
668  * backups/replication standbys, etc. A new file will be written on next
669  * shutdown.
670  *
671  * Note: it's okay if the PGSS_TEXT_FILE is included in a basebackup,
672  * because we remove that file on startup; it acts inversely to
673  * PGSS_DUMP_FILE, in that it is only supposed to be around when the
674  * server is running, whereas PGSS_DUMP_FILE is only supposed to be around
675  * when the server is not running. Leaving the file creates no danger of
676  * a newly restored database having a spurious record of execution costs,
677  * which is what we're really concerned about here.
678  */
679  unlink(PGSS_DUMP_FILE);
680 
681  return;
682 
683 read_error:
684  ereport(LOG,
686  errmsg("could not read file \"%s\": %m",
687  PGSS_DUMP_FILE)));
688  goto fail;
689 data_error:
690  ereport(LOG,
691  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
692  errmsg("ignoring invalid data in file \"%s\"",
693  PGSS_DUMP_FILE)));
694  goto fail;
695 write_error:
696  ereport(LOG,
698  errmsg("could not write file \"%s\": %m",
699  PGSS_TEXT_FILE)));
700 fail:
701  if (buffer)
702  pfree(buffer);
703  if (file)
704  FreeFile(file);
705  if (qfile)
706  FreeFile(qfile);
707  /* If possible, throw away the bogus file; ignore any error */
708  unlink(PGSS_DUMP_FILE);
709 
710  /*
711  * Don't unlink PGSS_TEXT_FILE here; it should always be around while the
712  * server is running with pg_stat_statements enabled
713  */
714 }
715 
716 /*
717  * shmem_shutdown hook: Dump statistics into file.
718  *
719  * Note: we don't bother with acquiring lock, because there should be no
720  * other processes running when this is called.
721  */
722 static void
724 {
725  FILE *file;
726  char *qbuffer = NULL;
727  Size qbuffer_size = 0;
728  HASH_SEQ_STATUS hash_seq;
729  int32 num_entries;
730  pgssEntry *entry;
731 
732  /* Don't try to dump during a crash. */
733  if (code)
734  return;
735 
736  /* Safety check ... shouldn't get here unless shmem is set up. */
737  if (!pgss || !pgss_hash)
738  return;
739 
740  /* Don't dump if told not to. */
741  if (!pgss_save)
742  return;
743 
744  file = AllocateFile(PGSS_DUMP_FILE ".tmp", PG_BINARY_W);
745  if (file == NULL)
746  goto error;
747 
748  if (fwrite(&PGSS_FILE_HEADER, sizeof(uint32), 1, file) != 1)
749  goto error;
750  if (fwrite(&PGSS_PG_MAJOR_VERSION, sizeof(uint32), 1, file) != 1)
751  goto error;
752  num_entries = hash_get_num_entries(pgss_hash);
753  if (fwrite(&num_entries, sizeof(int32), 1, file) != 1)
754  goto error;
755 
756  qbuffer = qtext_load_file(&qbuffer_size);
757  if (qbuffer == NULL)
758  goto error;
759 
760  /*
761  * When serializing to disk, we store query texts immediately after their
762  * entry data. Any orphaned query texts are thereby excluded.
763  */
764  hash_seq_init(&hash_seq, pgss_hash);
765  while ((entry = hash_seq_search(&hash_seq)) != NULL)
766  {
767  int len = entry->query_len;
768  char *qstr = qtext_fetch(entry->query_offset, len,
769  qbuffer, qbuffer_size);
770 
771  if (qstr == NULL)
772  continue; /* Ignore any entries with bogus texts */
773 
774  if (fwrite(entry, sizeof(pgssEntry), 1, file) != 1 ||
775  fwrite(qstr, 1, len + 1, file) != len + 1)
776  {
777  /* note: we assume hash_seq_term won't change errno */
778  hash_seq_term(&hash_seq);
779  goto error;
780  }
781  }
782 
783  /* Dump global statistics for pg_stat_statements */
784  if (fwrite(&pgss->stats, sizeof(pgssGlobalStats), 1, file) != 1)
785  goto error;
786 
787  free(qbuffer);
788  qbuffer = NULL;
789 
790  if (FreeFile(file))
791  {
792  file = NULL;
793  goto error;
794  }
795 
796  /*
797  * Rename file into place, so we atomically replace any old one.
798  */
800 
801  /* Unlink query-texts file; it's not needed while shutdown */
802  unlink(PGSS_TEXT_FILE);
803 
804  return;
805 
806 error:
807  ereport(LOG,
809  errmsg("could not write file \"%s\": %m",
810  PGSS_DUMP_FILE ".tmp")));
811  free(qbuffer);
812  if (file)
813  FreeFile(file);
814  unlink(PGSS_DUMP_FILE ".tmp");
815  unlink(PGSS_TEXT_FILE);
816 }
817 
818 /*
819  * Post-parse-analysis hook: mark query with a queryId
820  */
821 static void
823 {
825  prev_post_parse_analyze_hook(pstate, query, jstate);
826 
827  /* Safety check... */
829  return;
830 
831  /*
832  * Clear queryId for prepared statements related utility, as those will
833  * inherit from the underlying statement's one (except DEALLOCATE which is
834  * entirely untracked).
835  */
836  if (query->utilityStmt)
837  {
839  {
840  query->queryId = UINT64CONST(0);
841  return;
842  }
843  }
844 
845  /*
846  * If query jumbling were able to identify any ignorable constants, we
847  * immediately create a hash table entry for the query, so that we can
848  * record the normalized form of the query string. If there were no such
849  * constants, the normalized string would be the same as the query text
850  * anyway, so there's no need for an early entry.
851  */
852  if (jstate && jstate->clocations_count > 0)
853  pgss_store(pstate->p_sourcetext,
854  query->queryId,
855  query->stmt_location,
856  query->stmt_len,
857  PGSS_INVALID,
858  0,
859  0,
860  NULL,
861  NULL,
862  NULL,
863  jstate);
864 }
865 
866 /*
867  * Planner hook: forward to regular planner, but measure planning time
868  * if needed.
869  */
870 static PlannedStmt *
872  const char *query_string,
873  int cursorOptions,
874  ParamListInfo boundParams)
875 {
876  PlannedStmt *result;
877 
878  /*
879  * We can't process the query if no query_string is provided, as
880  * pgss_store needs it. We also ignore query without queryid, as it would
881  * be treated as a utility statement, which may not be the case.
882  *
883  * Note that planner_hook can be called from the planner itself, so we
884  * have a specific nesting level for the planner. However, utility
885  * commands containing optimizable statements can also call the planner,
886  * same for regular DML (for instance for underlying foreign key queries).
887  * So testing the planner nesting level only is not enough to detect real
888  * top level planner call.
889  */
891  && pgss_track_planning && query_string
892  && parse->queryId != UINT64CONST(0))
893  {
894  instr_time start;
896  BufferUsage bufusage_start,
897  bufusage;
898  WalUsage walusage_start,
899  walusage;
900 
901  /* We need to track buffer usage as the planner can access them. */
902  bufusage_start = pgBufferUsage;
903 
904  /*
905  * Similarly the planner could write some WAL records in some cases
906  * (e.g. setting a hint bit with those being WAL-logged)
907  */
908  walusage_start = pgWalUsage;
909  INSTR_TIME_SET_CURRENT(start);
910 
912  PG_TRY();
913  {
914  if (prev_planner_hook)
915  result = prev_planner_hook(parse, query_string, cursorOptions,
916  boundParams);
917  else
918  result = standard_planner(parse, query_string, cursorOptions,
919  boundParams);
920  }
921  PG_FINALLY();
922  {
924  }
925  PG_END_TRY();
926 
929 
930  /* calc differences of buffer counters. */
931  memset(&bufusage, 0, sizeof(BufferUsage));
932  BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start);
933 
934  /* calc differences of WAL counters. */
935  memset(&walusage, 0, sizeof(WalUsage));
936  WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start);
937 
938  pgss_store(query_string,
939  parse->queryId,
940  parse->stmt_location,
941  parse->stmt_len,
942  PGSS_PLAN,
944  0,
945  &bufusage,
946  &walusage,
947  NULL,
948  NULL);
949  }
950  else
951  {
952  if (prev_planner_hook)
953  result = prev_planner_hook(parse, query_string, cursorOptions,
954  boundParams);
955  else
956  result = standard_planner(parse, query_string, cursorOptions,
957  boundParams);
958  }
959 
960  return result;
961 }
962 
963 /*
964  * ExecutorStart hook: start up tracking if needed
965  */
966 static void
967 pgss_ExecutorStart(QueryDesc *queryDesc, int eflags)
968 {
969  if (prev_ExecutorStart)
970  prev_ExecutorStart(queryDesc, eflags);
971  else
972  standard_ExecutorStart(queryDesc, eflags);
973 
974  /*
975  * If query has queryId zero, don't track it. This prevents double
976  * counting of optimizable statements that are directly contained in
977  * utility statements.
978  */
979  if (pgss_enabled(exec_nested_level) && queryDesc->plannedstmt->queryId != UINT64CONST(0))
980  {
981  /*
982  * Set up to track total elapsed time in ExecutorRun. Make sure the
983  * space is allocated in the per-query context so it will go away at
984  * ExecutorEnd.
985  */
986  if (queryDesc->totaltime == NULL)
987  {
988  MemoryContext oldcxt;
989 
990  oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
991  queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL, false);
992  MemoryContextSwitchTo(oldcxt);
993  }
994  }
995 }
996 
997 /*
998  * ExecutorRun hook: all we need do is track nesting depth
999  */
1000 static void
1001 pgss_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, uint64 count,
1002  bool execute_once)
1003 {
1005  PG_TRY();
1006  {
1007  if (prev_ExecutorRun)
1008  prev_ExecutorRun(queryDesc, direction, count, execute_once);
1009  else
1010  standard_ExecutorRun(queryDesc, direction, count, execute_once);
1011  }
1012  PG_FINALLY();
1013  {
1015  }
1016  PG_END_TRY();
1017 }
1018 
1019 /*
1020  * ExecutorFinish hook: all we need do is track nesting depth
1021  */
1022 static void
1024 {
1026  PG_TRY();
1027  {
1028  if (prev_ExecutorFinish)
1029  prev_ExecutorFinish(queryDesc);
1030  else
1031  standard_ExecutorFinish(queryDesc);
1032  }
1033  PG_FINALLY();
1034  {
1036  }
1037  PG_END_TRY();
1038 }
1039 
1040 /*
1041  * ExecutorEnd hook: store results if needed
1042  */
1043 static void
1045 {
1046  uint64 queryId = queryDesc->plannedstmt->queryId;
1047 
1048  if (queryId != UINT64CONST(0) && queryDesc->totaltime &&
1050  {
1051  /*
1052  * Make sure stats accumulation is done. (Note: it's okay if several
1053  * levels of hook all do this.)
1054  */
1055  InstrEndLoop(queryDesc->totaltime);
1056 
1057  pgss_store(queryDesc->sourceText,
1058  queryId,
1059  queryDesc->plannedstmt->stmt_location,
1060  queryDesc->plannedstmt->stmt_len,
1061  PGSS_EXEC,
1062  queryDesc->totaltime->total * 1000.0, /* convert to msec */
1063  queryDesc->estate->es_processed,
1064  &queryDesc->totaltime->bufusage,
1065  &queryDesc->totaltime->walusage,
1066  queryDesc->estate->es_jit ? &queryDesc->estate->es_jit->instr : NULL,
1067  NULL);
1068  }
1069 
1070  if (prev_ExecutorEnd)
1071  prev_ExecutorEnd(queryDesc);
1072  else
1073  standard_ExecutorEnd(queryDesc);
1074 }
1075 
1076 /*
1077  * ProcessUtility hook
1078  */
1079 static void
1080 pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
1081  bool readOnlyTree,
1082  ProcessUtilityContext context,
1083  ParamListInfo params, QueryEnvironment *queryEnv,
1085 {
1086  Node *parsetree = pstmt->utilityStmt;
1087  uint64 saved_queryId = pstmt->queryId;
1088  int saved_stmt_location = pstmt->stmt_location;
1089  int saved_stmt_len = pstmt->stmt_len;
1090 
1091  /*
1092  * Force utility statements to get queryId zero. We do this even in cases
1093  * where the statement contains an optimizable statement for which a
1094  * queryId could be derived (such as EXPLAIN or DECLARE CURSOR). For such
1095  * cases, runtime control will first go through ProcessUtility and then
1096  * the executor, and we don't want the executor hooks to do anything,
1097  * since we are already measuring the statement's costs at the utility
1098  * level.
1099  *
1100  * Note that this is only done if pg_stat_statements is enabled and
1101  * configured to track utility statements, in the unlikely possibility
1102  * that user configured another extension to handle utility statements
1103  * only.
1104  */
1106  pstmt->queryId = UINT64CONST(0);
1107 
1108  /*
1109  * If it's an EXECUTE statement, we don't track it and don't increment the
1110  * nesting level. This allows the cycles to be charged to the underlying
1111  * PREPARE instead (by the Executor hooks), which is much more useful.
1112  *
1113  * We also don't track execution of PREPARE. If we did, we would get one
1114  * hash table entry for the PREPARE (with hash calculated from the query
1115  * string), and then a different one with the same query string (but hash
1116  * calculated from the query tree) would be used to accumulate costs of
1117  * ensuing EXECUTEs. This would be confusing, and inconsistent with other
1118  * cases where planning time is not included at all.
1119  *
1120  * Likewise, we don't track execution of DEALLOCATE.
1121  */
1123  PGSS_HANDLED_UTILITY(parsetree))
1124  {
1125  instr_time start;
1127  uint64 rows;
1128  BufferUsage bufusage_start,
1129  bufusage;
1130  WalUsage walusage_start,
1131  walusage;
1132 
1133  bufusage_start = pgBufferUsage;
1134  walusage_start = pgWalUsage;
1135  INSTR_TIME_SET_CURRENT(start);
1136 
1138  PG_TRY();
1139  {
1140  if (prev_ProcessUtility)
1141  prev_ProcessUtility(pstmt, queryString, readOnlyTree,
1142  context, params, queryEnv,
1143  dest, qc);
1144  else
1145  standard_ProcessUtility(pstmt, queryString, readOnlyTree,
1146  context, params, queryEnv,
1147  dest, qc);
1148  }
1149  PG_FINALLY();
1150  {
1152  }
1153  PG_END_TRY();
1154 
1155  /*
1156  * CAUTION: do not access the *pstmt data structure again below here.
1157  * If it was a ROLLBACK or similar, that data structure may have been
1158  * freed. We must copy everything we still need into local variables,
1159  * which we did above.
1160  *
1161  * For the same reason, we can't risk restoring pstmt->queryId to its
1162  * former value, which'd otherwise be a good idea.
1163  */
1164 
1166  INSTR_TIME_SUBTRACT(duration, start);
1167 
1168  /*
1169  * Track the total number of rows retrieved or affected by the utility
1170  * statements of COPY, FETCH, CREATE TABLE AS, CREATE MATERIALIZED
1171  * VIEW, REFRESH MATERIALIZED VIEW and SELECT INTO.
1172  */
1173  rows = (qc && (qc->commandTag == CMDTAG_COPY ||
1174  qc->commandTag == CMDTAG_FETCH ||
1175  qc->commandTag == CMDTAG_SELECT ||
1176  qc->commandTag == CMDTAG_REFRESH_MATERIALIZED_VIEW)) ?
1177  qc->nprocessed : 0;
1178 
1179  /* calc differences of buffer counters. */
1180  memset(&bufusage, 0, sizeof(BufferUsage));
1181  BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start);
1182 
1183  /* calc differences of WAL counters. */
1184  memset(&walusage, 0, sizeof(WalUsage));
1185  WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start);
1186 
1187  pgss_store(queryString,
1188  saved_queryId,
1189  saved_stmt_location,
1190  saved_stmt_len,
1191  PGSS_EXEC,
1193  rows,
1194  &bufusage,
1195  &walusage,
1196  NULL,
1197  NULL);
1198  }
1199  else
1200  {
1201  if (prev_ProcessUtility)
1202  prev_ProcessUtility(pstmt, queryString, readOnlyTree,
1203  context, params, queryEnv,
1204  dest, qc);
1205  else
1206  standard_ProcessUtility(pstmt, queryString, readOnlyTree,
1207  context, params, queryEnv,
1208  dest, qc);
1209  }
1210 }
1211 
1212 /*
1213  * Store some statistics for a statement.
1214  *
1215  * If jstate is not NULL then we're trying to create an entry for which
1216  * we have no statistics as yet; we just want to record the normalized
1217  * query string. total_time, rows, bufusage and walusage are ignored in this
1218  * case.
1219  *
1220  * If kind is PGSS_PLAN or PGSS_EXEC, its value is used as the array position
1221  * for the arrays in the Counters field.
1222  */
1223 static void
1224 pgss_store(const char *query, uint64 queryId,
1225  int query_location, int query_len,
1226  pgssStoreKind kind,
1227  double total_time, uint64 rows,
1228  const BufferUsage *bufusage,
1229  const WalUsage *walusage,
1230  const struct JitInstrumentation *jitusage,
1231  JumbleState *jstate)
1232 {
1233  pgssHashKey key;
1234  pgssEntry *entry;
1235  char *norm_query = NULL;
1236  int encoding = GetDatabaseEncoding();
1237 
1238  Assert(query != NULL);
1239 
1240  /* Safety check... */
1241  if (!pgss || !pgss_hash)
1242  return;
1243 
1244  /*
1245  * Nothing to do if compute_query_id isn't enabled and no other module
1246  * computed a query identifier.
1247  */
1248  if (queryId == UINT64CONST(0))
1249  return;
1250 
1251  /*
1252  * Confine our attention to the relevant part of the string, if the query
1253  * is a portion of a multi-statement source string, and update query
1254  * location and length if needed.
1255  */
1256  query = CleanQuerytext(query, &query_location, &query_len);
1257 
1258  /* Set up key for hashtable search */
1259 
1260  /* memset() is required when pgssHashKey is without padding only */
1261  memset(&key, 0, sizeof(pgssHashKey));
1262 
1263  key.userid = GetUserId();
1264  key.dbid = MyDatabaseId;
1265  key.queryid = queryId;
1266  key.toplevel = (exec_nested_level == 0);
1267 
1268  /* Lookup the hash table entry with shared lock. */
1270 
1271  entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
1272 
1273  /* Create new entry, if not present */
1274  if (!entry)
1275  {
1276  Size query_offset;
1277  int gc_count;
1278  bool stored;
1279  bool do_gc;
1280 
1281  /*
1282  * Create a new, normalized query string if caller asked. We don't
1283  * need to hold the lock while doing this work. (Note: in any case,
1284  * it's possible that someone else creates a duplicate hashtable entry
1285  * in the interval where we don't hold the lock below. That case is
1286  * handled by entry_alloc.)
1287  */
1288  if (jstate)
1289  {
1291  norm_query = generate_normalized_query(jstate, query,
1292  query_location,
1293  &query_len);
1295  }
1296 
1297  /* Append new query text to file with only shared lock held */
1298  stored = qtext_store(norm_query ? norm_query : query, query_len,
1299  &query_offset, &gc_count);
1300 
1301  /*
1302  * Determine whether we need to garbage collect external query texts
1303  * while the shared lock is still held. This micro-optimization
1304  * avoids taking the time to decide this while holding exclusive lock.
1305  */
1306  do_gc = need_gc_qtexts();
1307 
1308  /* Need exclusive lock to make a new hashtable entry - promote */
1311 
1312  /*
1313  * A garbage collection may have occurred while we weren't holding the
1314  * lock. In the unlikely event that this happens, the query text we
1315  * stored above will have been garbage collected, so write it again.
1316  * This should be infrequent enough that doing it while holding
1317  * exclusive lock isn't a performance problem.
1318  */
1319  if (!stored || pgss->gc_count != gc_count)
1320  stored = qtext_store(norm_query ? norm_query : query, query_len,
1321  &query_offset, NULL);
1322 
1323  /* If we failed to write to the text file, give up */
1324  if (!stored)
1325  goto done;
1326 
1327  /* OK to create a new hashtable entry */
1328  entry = entry_alloc(&key, query_offset, query_len, encoding,
1329  jstate != NULL);
1330 
1331  /* If needed, perform garbage collection while exclusive lock held */
1332  if (do_gc)
1333  gc_qtexts();
1334  }
1335 
1336  /* Increment the counts, except when jstate is not NULL */
1337  if (!jstate)
1338  {
1339  /*
1340  * Grab the spinlock while updating the counters (see comment about
1341  * locking rules at the head of the file)
1342  */
1343  volatile pgssEntry *e = (volatile pgssEntry *) entry;
1344 
1345  Assert(kind == PGSS_PLAN || kind == PGSS_EXEC);
1346 
1347  SpinLockAcquire(&e->mutex);
1348 
1349  /* "Unstick" entry if it was previously sticky */
1350  if (IS_STICKY(e->counters))
1351  e->counters.usage = USAGE_INIT;
1352 
1353  e->counters.calls[kind] += 1;
1354  e->counters.total_time[kind] += total_time;
1355 
1356  if (e->counters.calls[kind] == 1)
1357  {
1358  e->counters.min_time[kind] = total_time;
1359  e->counters.max_time[kind] = total_time;
1360  e->counters.mean_time[kind] = total_time;
1361  }
1362  else
1363  {
1364  /*
1365  * Welford's method for accurately computing variance. See
1366  * <http://www.johndcook.com/blog/standard_deviation/>
1367  */
1368  double old_mean = e->counters.mean_time[kind];
1369 
1370  e->counters.mean_time[kind] +=
1371  (total_time - old_mean) / e->counters.calls[kind];
1372  e->counters.sum_var_time[kind] +=
1373  (total_time - old_mean) * (total_time - e->counters.mean_time[kind]);
1374 
1375  /* calculate min and max time */
1376  if (e->counters.min_time[kind] > total_time)
1377  e->counters.min_time[kind] = total_time;
1378  if (e->counters.max_time[kind] < total_time)
1379  e->counters.max_time[kind] = total_time;
1380  }
1381  e->counters.rows += rows;
1382  e->counters.shared_blks_hit += bufusage->shared_blks_hit;
1383  e->counters.shared_blks_read += bufusage->shared_blks_read;
1384  e->counters.shared_blks_dirtied += bufusage->shared_blks_dirtied;
1385  e->counters.shared_blks_written += bufusage->shared_blks_written;
1386  e->counters.local_blks_hit += bufusage->local_blks_hit;
1387  e->counters.local_blks_read += bufusage->local_blks_read;
1388  e->counters.local_blks_dirtied += bufusage->local_blks_dirtied;
1389  e->counters.local_blks_written += bufusage->local_blks_written;
1390  e->counters.temp_blks_read += bufusage->temp_blks_read;
1391  e->counters.temp_blks_written += bufusage->temp_blks_written;
1392  e->counters.blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_read_time);
1393  e->counters.blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_write_time);
1394  e->counters.temp_blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->temp_blk_read_time);
1395  e->counters.temp_blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->temp_blk_write_time);
1396  e->counters.usage += USAGE_EXEC(total_time);
1397  e->counters.wal_records += walusage->wal_records;
1398  e->counters.wal_fpi += walusage->wal_fpi;
1399  e->counters.wal_bytes += walusage->wal_bytes;
1400  if (jitusage)
1401  {
1402  e->counters.jit_functions += jitusage->created_functions;
1403  e->counters.jit_generation_time += INSTR_TIME_GET_MILLISEC(jitusage->generation_counter);
1404 
1406  e->counters.jit_inlining_count++;
1407  e->counters.jit_inlining_time += INSTR_TIME_GET_MILLISEC(jitusage->inlining_counter);
1408 
1410  e->counters.jit_optimization_count++;
1411  e->counters.jit_optimization_time += INSTR_TIME_GET_MILLISEC(jitusage->optimization_counter);
1412 
1414  e->counters.jit_emission_count++;
1415  e->counters.jit_emission_time += INSTR_TIME_GET_MILLISEC(jitusage->emission_counter);
1416  }
1417 
1418  SpinLockRelease(&e->mutex);
1419  }
1420 
1421 done:
1423 
1424  /* We postpone this clean-up until we're out of the lock */
1425  if (norm_query)
1426  pfree(norm_query);
1427 }
1428 
1429 /*
1430  * Reset statement statistics corresponding to userid, dbid, and queryid.
1431  */
1432 Datum
1434 {
1435  Oid userid;
1436  Oid dbid;
1437  uint64 queryid;
1438 
1439  userid = PG_GETARG_OID(0);
1440  dbid = PG_GETARG_OID(1);
1441  queryid = (uint64) PG_GETARG_INT64(2);
1442 
1443  entry_reset(userid, dbid, queryid);
1444 
1445  PG_RETURN_VOID();
1446 }
1447 
1448 /*
1449  * Reset statement statistics.
1450  */
1451 Datum
1453 {
1454  entry_reset(0, 0, 0);
1455 
1456  PG_RETURN_VOID();
1457 }
1458 
1459 /* Number of output arguments (columns) for various API versions */
1460 #define PG_STAT_STATEMENTS_COLS_V1_0 14
1461 #define PG_STAT_STATEMENTS_COLS_V1_1 18
1462 #define PG_STAT_STATEMENTS_COLS_V1_2 19
1463 #define PG_STAT_STATEMENTS_COLS_V1_3 23
1464 #define PG_STAT_STATEMENTS_COLS_V1_8 32
1465 #define PG_STAT_STATEMENTS_COLS_V1_9 33
1466 #define PG_STAT_STATEMENTS_COLS_V1_10 43
1467 #define PG_STAT_STATEMENTS_COLS 43 /* maximum of above */
1468 
1469 /*
1470  * Retrieve statement statistics.
1471  *
1472  * The SQL API of this function has changed multiple times, and will likely
1473  * do so again in future. To support the case where a newer version of this
1474  * loadable module is being used with an old SQL declaration of the function,
1475  * we continue to support the older API versions. For 1.2 and later, the
1476  * expected API version is identified by embedding it in the C name of the
1477  * function. Unfortunately we weren't bright enough to do that for 1.1.
1478  */
1479 Datum
1481 {
1482  bool showtext = PG_GETARG_BOOL(0);
1483 
1484  pg_stat_statements_internal(fcinfo, PGSS_V1_10, showtext);
1485 
1486  return (Datum) 0;
1487 }
1488 
1489 Datum
1491 {
1492  bool showtext = PG_GETARG_BOOL(0);
1493 
1494  pg_stat_statements_internal(fcinfo, PGSS_V1_9, showtext);
1495 
1496  return (Datum) 0;
1497 }
1498 
1499 Datum
1501 {
1502  bool showtext = PG_GETARG_BOOL(0);
1503 
1504  pg_stat_statements_internal(fcinfo, PGSS_V1_8, showtext);
1505 
1506  return (Datum) 0;
1507 }
1508 
1509 Datum
1511 {
1512  bool showtext = PG_GETARG_BOOL(0);
1513 
1514  pg_stat_statements_internal(fcinfo, PGSS_V1_3, showtext);
1515 
1516  return (Datum) 0;
1517 }
1518 
1519 Datum
1521 {
1522  bool showtext = PG_GETARG_BOOL(0);
1523 
1524  pg_stat_statements_internal(fcinfo, PGSS_V1_2, showtext);
1525 
1526  return (Datum) 0;
1527 }
1528 
1529 /*
1530  * Legacy entry point for pg_stat_statements() API versions 1.0 and 1.1.
1531  * This can be removed someday, perhaps.
1532  */
1533 Datum
1535 {
1536  /* If it's really API 1.1, we'll figure that out below */
1537  pg_stat_statements_internal(fcinfo, PGSS_V1_0, true);
1538 
1539  return (Datum) 0;
1540 }
1541 
1542 /* Common code for all versions of pg_stat_statements() */
1543 static void
1545  pgssVersion api_version,
1546  bool showtext)
1547 {
1548  ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
1549  Oid userid = GetUserId();
1550  bool is_allowed_role = false;
1551  char *qbuffer = NULL;
1552  Size qbuffer_size = 0;
1553  Size extent = 0;
1554  int gc_count = 0;
1555  HASH_SEQ_STATUS hash_seq;
1556  pgssEntry *entry;
1557 
1558  /*
1559  * Superusers or roles with the privileges of pg_read_all_stats members
1560  * are allowed
1561  */
1562  is_allowed_role = has_privs_of_role(userid, ROLE_PG_READ_ALL_STATS);
1563 
1564  /* hash table must exist already */
1565  if (!pgss || !pgss_hash)
1566  ereport(ERROR,
1567  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1568  errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
1569 
1570  InitMaterializedSRF(fcinfo, 0);
1571 
1572  /*
1573  * Check we have the expected number of output arguments. Aside from
1574  * being a good safety check, we need a kluge here to detect API version
1575  * 1.1, which was wedged into the code in an ill-considered way.
1576  */
1577  switch (rsinfo->setDesc->natts)
1578  {
1580  if (api_version != PGSS_V1_0)
1581  elog(ERROR, "incorrect number of output arguments");
1582  break;
1584  /* pg_stat_statements() should have told us 1.0 */
1585  if (api_version != PGSS_V1_0)
1586  elog(ERROR, "incorrect number of output arguments");
1587  api_version = PGSS_V1_1;
1588  break;
1590  if (api_version != PGSS_V1_2)
1591  elog(ERROR, "incorrect number of output arguments");
1592  break;
1594  if (api_version != PGSS_V1_3)
1595  elog(ERROR, "incorrect number of output arguments");
1596  break;
1598  if (api_version != PGSS_V1_8)
1599  elog(ERROR, "incorrect number of output arguments");
1600  break;
1602  if (api_version != PGSS_V1_9)
1603  elog(ERROR, "incorrect number of output arguments");
1604  break;
1606  if (api_version != PGSS_V1_10)
1607  elog(ERROR, "incorrect number of output arguments");
1608  break;
1609  default:
1610  elog(ERROR, "incorrect number of output arguments");
1611  }
1612 
1613  /*
1614  * We'd like to load the query text file (if needed) while not holding any
1615  * lock on pgss->lock. In the worst case we'll have to do this again
1616  * after we have the lock, but it's unlikely enough to make this a win
1617  * despite occasional duplicated work. We need to reload if anybody
1618  * writes to the file (either a retail qtext_store(), or a garbage
1619  * collection) between this point and where we've gotten shared lock. If
1620  * a qtext_store is actually in progress when we look, we might as well
1621  * skip the speculative load entirely.
1622  */
1623  if (showtext)
1624  {
1625  int n_writers;
1626 
1627  /* Take the mutex so we can examine variables */
1628  {
1629  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
1630 
1631  SpinLockAcquire(&s->mutex);
1632  extent = s->extent;
1633  n_writers = s->n_writers;
1634  gc_count = s->gc_count;
1635  SpinLockRelease(&s->mutex);
1636  }
1637 
1638  /* No point in loading file now if there are active writers */
1639  if (n_writers == 0)
1640  qbuffer = qtext_load_file(&qbuffer_size);
1641  }
1642 
1643  /*
1644  * Get shared lock, load or reload the query text file if we must, and
1645  * iterate over the hashtable entries.
1646  *
1647  * With a large hash table, we might be holding the lock rather longer
1648  * than one could wish. However, this only blocks creation of new hash
1649  * table entries, and the larger the hash table the less likely that is to
1650  * be needed. So we can hope this is okay. Perhaps someday we'll decide
1651  * we need to partition the hash table to limit the time spent holding any
1652  * one lock.
1653  */
1655 
1656  if (showtext)
1657  {
1658  /*
1659  * Here it is safe to examine extent and gc_count without taking the
1660  * mutex. Note that although other processes might change
1661  * pgss->extent just after we look at it, the strings they then write
1662  * into the file cannot yet be referenced in the hashtable, so we
1663  * don't care whether we see them or not.
1664  *
1665  * If qtext_load_file fails, we just press on; we'll return NULL for
1666  * every query text.
1667  */
1668  if (qbuffer == NULL ||
1669  pgss->extent != extent ||
1670  pgss->gc_count != gc_count)
1671  {
1672  free(qbuffer);
1673  qbuffer = qtext_load_file(&qbuffer_size);
1674  }
1675  }
1676 
1677  hash_seq_init(&hash_seq, pgss_hash);
1678  while ((entry = hash_seq_search(&hash_seq)) != NULL)
1679  {
1681  bool nulls[PG_STAT_STATEMENTS_COLS];
1682  int i = 0;
1683  Counters tmp;
1684  double stddev;
1685  int64 queryid = entry->key.queryid;
1686 
1687  memset(values, 0, sizeof(values));
1688  memset(nulls, 0, sizeof(nulls));
1689 
1690  values[i++] = ObjectIdGetDatum(entry->key.userid);
1691  values[i++] = ObjectIdGetDatum(entry->key.dbid);
1692  if (api_version >= PGSS_V1_9)
1693  values[i++] = BoolGetDatum(entry->key.toplevel);
1694 
1695  if (is_allowed_role || entry->key.userid == userid)
1696  {
1697  if (api_version >= PGSS_V1_2)
1698  values[i++] = Int64GetDatumFast(queryid);
1699 
1700  if (showtext)
1701  {
1702  char *qstr = qtext_fetch(entry->query_offset,
1703  entry->query_len,
1704  qbuffer,
1705  qbuffer_size);
1706 
1707  if (qstr)
1708  {
1709  char *enc;
1710 
1711  enc = pg_any_to_server(qstr,
1712  entry->query_len,
1713  entry->encoding);
1714 
1716 
1717  if (enc != qstr)
1718  pfree(enc);
1719  }
1720  else
1721  {
1722  /* Just return a null if we fail to find the text */
1723  nulls[i++] = true;
1724  }
1725  }
1726  else
1727  {
1728  /* Query text not requested */
1729  nulls[i++] = true;
1730  }
1731  }
1732  else
1733  {
1734  /* Don't show queryid */
1735  if (api_version >= PGSS_V1_2)
1736  nulls[i++] = true;
1737 
1738  /*
1739  * Don't show query text, but hint as to the reason for not doing
1740  * so if it was requested
1741  */
1742  if (showtext)
1743  values[i++] = CStringGetTextDatum("<insufficient privilege>");
1744  else
1745  nulls[i++] = true;
1746  }
1747 
1748  /* copy counters to a local variable to keep locking time short */
1749  {
1750  volatile pgssEntry *e = (volatile pgssEntry *) entry;
1751 
1752  SpinLockAcquire(&e->mutex);
1753  tmp = e->counters;
1754  SpinLockRelease(&e->mutex);
1755  }
1756 
1757  /* Skip entry if unexecuted (ie, it's a pending "sticky" entry) */
1758  if (IS_STICKY(tmp))
1759  continue;
1760 
1761  /* Note that we rely on PGSS_PLAN being 0 and PGSS_EXEC being 1. */
1762  for (int kind = 0; kind < PGSS_NUMKIND; kind++)
1763  {
1764  if (kind == PGSS_EXEC || api_version >= PGSS_V1_8)
1765  {
1766  values[i++] = Int64GetDatumFast(tmp.calls[kind]);
1767  values[i++] = Float8GetDatumFast(tmp.total_time[kind]);
1768  }
1769 
1770  if ((kind == PGSS_EXEC && api_version >= PGSS_V1_3) ||
1771  api_version >= PGSS_V1_8)
1772  {
1773  values[i++] = Float8GetDatumFast(tmp.min_time[kind]);
1774  values[i++] = Float8GetDatumFast(tmp.max_time[kind]);
1775  values[i++] = Float8GetDatumFast(tmp.mean_time[kind]);
1776 
1777  /*
1778  * Note we are calculating the population variance here, not
1779  * the sample variance, as we have data for the whole
1780  * population, so Bessel's correction is not used, and we
1781  * don't divide by tmp.calls - 1.
1782  */
1783  if (tmp.calls[kind] > 1)
1784  stddev = sqrt(tmp.sum_var_time[kind] / tmp.calls[kind]);
1785  else
1786  stddev = 0.0;
1787  values[i++] = Float8GetDatumFast(stddev);
1788  }
1789  }
1790  values[i++] = Int64GetDatumFast(tmp.rows);
1793  if (api_version >= PGSS_V1_1)
1798  if (api_version >= PGSS_V1_1)
1803  if (api_version >= PGSS_V1_1)
1804  {
1807  }
1808  if (api_version >= PGSS_V1_10)
1809  {
1812  }
1813  if (api_version >= PGSS_V1_8)
1814  {
1815  char buf[256];
1816  Datum wal_bytes;
1817 
1819  values[i++] = Int64GetDatumFast(tmp.wal_fpi);
1820 
1821  snprintf(buf, sizeof buf, UINT64_FORMAT, tmp.wal_bytes);
1822 
1823  /* Convert to numeric. */
1824  wal_bytes = DirectFunctionCall3(numeric_in,
1826  ObjectIdGetDatum(0),
1827  Int32GetDatum(-1));
1828  values[i++] = wal_bytes;
1829  }
1830  if (api_version >= PGSS_V1_10)
1831  {
1840  }
1841 
1842  Assert(i == (api_version == PGSS_V1_0 ? PG_STAT_STATEMENTS_COLS_V1_0 :
1843  api_version == PGSS_V1_1 ? PG_STAT_STATEMENTS_COLS_V1_1 :
1844  api_version == PGSS_V1_2 ? PG_STAT_STATEMENTS_COLS_V1_2 :
1845  api_version == PGSS_V1_3 ? PG_STAT_STATEMENTS_COLS_V1_3 :
1846  api_version == PGSS_V1_8 ? PG_STAT_STATEMENTS_COLS_V1_8 :
1847  api_version == PGSS_V1_9 ? PG_STAT_STATEMENTS_COLS_V1_9 :
1848  api_version == PGSS_V1_10 ? PG_STAT_STATEMENTS_COLS_V1_10 :
1849  -1 /* fail if you forget to update this assert */ ));
1850 
1851  tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
1852  }
1853 
1855 
1856  free(qbuffer);
1857 }
1858 
1859 /* Number of output arguments (columns) for pg_stat_statements_info */
1860 #define PG_STAT_STATEMENTS_INFO_COLS 2
1861 
1862 /*
1863  * Return statistics of pg_stat_statements.
1864  */
1865 Datum
1867 {
1868  pgssGlobalStats stats;
1869  TupleDesc tupdesc;
1871  bool nulls[PG_STAT_STATEMENTS_INFO_COLS] = {0};
1872 
1873  if (!pgss || !pgss_hash)
1874  ereport(ERROR,
1875  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1876  errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
1877 
1878  /* Build a tuple descriptor for our result type */
1879  if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
1880  elog(ERROR, "return type must be a row type");
1881 
1882  /* Read global statistics for pg_stat_statements */
1883  {
1884  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
1885 
1886  SpinLockAcquire(&s->mutex);
1887  stats = s->stats;
1888  SpinLockRelease(&s->mutex);
1889  }
1890 
1891  values[0] = Int64GetDatum(stats.dealloc);
1893 
1895 }
1896 
1897 /*
1898  * Estimate shared memory space needed.
1899  */
1900 static Size
1902 {
1903  Size size;
1904 
1905  size = MAXALIGN(sizeof(pgssSharedState));
1906  size = add_size(size, hash_estimate_size(pgss_max, sizeof(pgssEntry)));
1907 
1908  return size;
1909 }
1910 
1911 /*
1912  * Allocate a new hashtable entry.
1913  * caller must hold an exclusive lock on pgss->lock
1914  *
1915  * "query" need not be null-terminated; we rely on query_len instead
1916  *
1917  * If "sticky" is true, make the new entry artificially sticky so that it will
1918  * probably still be there when the query finishes execution. We do this by
1919  * giving it a median usage value rather than the normal value. (Strictly
1920  * speaking, query strings are normalized on a best effort basis, though it
1921  * would be difficult to demonstrate this even under artificial conditions.)
1922  *
1923  * Note: despite needing exclusive lock, it's not an error for the target
1924  * entry to already exist. This is because pgss_store releases and
1925  * reacquires lock after failing to find a match; so someone else could
1926  * have made the entry while we waited to get exclusive lock.
1927  */
1928 static pgssEntry *
1929 entry_alloc(pgssHashKey *key, Size query_offset, int query_len, int encoding,
1930  bool sticky)
1931 {
1932  pgssEntry *entry;
1933  bool found;
1934 
1935  /* Make space if needed */
1937  entry_dealloc();
1938 
1939  /* Find or create an entry with desired hash code */
1940  entry = (pgssEntry *) hash_search(pgss_hash, key, HASH_ENTER, &found);
1941 
1942  if (!found)
1943  {
1944  /* New entry, initialize it */
1945 
1946  /* reset the statistics */
1947  memset(&entry->counters, 0, sizeof(Counters));
1948  /* set the appropriate initial usage count */
1949  entry->counters.usage = sticky ? pgss->cur_median_usage : USAGE_INIT;
1950  /* re-initialize the mutex each time ... we assume no one using it */
1951  SpinLockInit(&entry->mutex);
1952  /* ... and don't forget the query text metadata */
1953  Assert(query_len >= 0);
1954  entry->query_offset = query_offset;
1955  entry->query_len = query_len;
1956  entry->encoding = encoding;
1957  }
1958 
1959  return entry;
1960 }
1961 
1962 /*
1963  * qsort comparator for sorting into increasing usage order
1964  */
1965 static int
1966 entry_cmp(const void *lhs, const void *rhs)
1967 {
1968  double l_usage = (*(pgssEntry *const *) lhs)->counters.usage;
1969  double r_usage = (*(pgssEntry *const *) rhs)->counters.usage;
1970 
1971  if (l_usage < r_usage)
1972  return -1;
1973  else if (l_usage > r_usage)
1974  return +1;
1975  else
1976  return 0;
1977 }
1978 
1979 /*
1980  * Deallocate least-used entries.
1981  *
1982  * Caller must hold an exclusive lock on pgss->lock.
1983  */
1984 static void
1986 {
1987  HASH_SEQ_STATUS hash_seq;
1988  pgssEntry **entries;
1989  pgssEntry *entry;
1990  int nvictims;
1991  int i;
1992  Size tottextlen;
1993  int nvalidtexts;
1994 
1995  /*
1996  * Sort entries by usage and deallocate USAGE_DEALLOC_PERCENT of them.
1997  * While we're scanning the table, apply the decay factor to the usage
1998  * values, and update the mean query length.
1999  *
2000  * Note that the mean query length is almost immediately obsolete, since
2001  * we compute it before not after discarding the least-used entries.
2002  * Hopefully, that doesn't affect the mean too much; it doesn't seem worth
2003  * making two passes to get a more current result. Likewise, the new
2004  * cur_median_usage includes the entries we're about to zap.
2005  */
2006 
2007  entries = palloc(hash_get_num_entries(pgss_hash) * sizeof(pgssEntry *));
2008 
2009  i = 0;
2010  tottextlen = 0;
2011  nvalidtexts = 0;
2012 
2013  hash_seq_init(&hash_seq, pgss_hash);
2014  while ((entry = hash_seq_search(&hash_seq)) != NULL)
2015  {
2016  entries[i++] = entry;
2017  /* "Sticky" entries get a different usage decay rate. */
2018  if (IS_STICKY(entry->counters))
2020  else
2022  /* In the mean length computation, ignore dropped texts. */
2023  if (entry->query_len >= 0)
2024  {
2025  tottextlen += entry->query_len + 1;
2026  nvalidtexts++;
2027  }
2028  }
2029 
2030  /* Sort into increasing order by usage */
2031  qsort(entries, i, sizeof(pgssEntry *), entry_cmp);
2032 
2033  /* Record the (approximate) median usage */
2034  if (i > 0)
2035  pgss->cur_median_usage = entries[i / 2]->counters.usage;
2036  /* Record the mean query length */
2037  if (nvalidtexts > 0)
2038  pgss->mean_query_len = tottextlen / nvalidtexts;
2039  else
2041 
2042  /* Now zap an appropriate fraction of lowest-usage entries */
2043  nvictims = Max(10, i * USAGE_DEALLOC_PERCENT / 100);
2044  nvictims = Min(nvictims, i);
2045 
2046  for (i = 0; i < nvictims; i++)
2047  {
2048  hash_search(pgss_hash, &entries[i]->key, HASH_REMOVE, NULL);
2049  }
2050 
2051  pfree(entries);
2052 
2053  /* Increment the number of times entries are deallocated */
2054  {
2055  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
2056 
2057  SpinLockAcquire(&s->mutex);
2058  s->stats.dealloc += 1;
2059  SpinLockRelease(&s->mutex);
2060  }
2061 }
2062 
2063 /*
2064  * Given a query string (not necessarily null-terminated), allocate a new
2065  * entry in the external query text file and store the string there.
2066  *
2067  * If successful, returns true, and stores the new entry's offset in the file
2068  * into *query_offset. Also, if gc_count isn't NULL, *gc_count is set to the
2069  * number of garbage collections that have occurred so far.
2070  *
2071  * On failure, returns false.
2072  *
2073  * At least a shared lock on pgss->lock must be held by the caller, so as
2074  * to prevent a concurrent garbage collection. Share-lock-holding callers
2075  * should pass a gc_count pointer to obtain the number of garbage collections,
2076  * so that they can recheck the count after obtaining exclusive lock to
2077  * detect whether a garbage collection occurred (and removed this entry).
2078  */
2079 static bool
2080 qtext_store(const char *query, int query_len,
2081  Size *query_offset, int *gc_count)
2082 {
2083  Size off;
2084  int fd;
2085 
2086  /*
2087  * We use a spinlock to protect extent/n_writers/gc_count, so that
2088  * multiple processes may execute this function concurrently.
2089  */
2090  {
2091  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
2092 
2093  SpinLockAcquire(&s->mutex);
2094  off = s->extent;
2095  s->extent += query_len + 1;
2096  s->n_writers++;
2097  if (gc_count)
2098  *gc_count = s->gc_count;
2099  SpinLockRelease(&s->mutex);
2100  }
2101 
2102  *query_offset = off;
2103 
2104  /*
2105  * Don't allow the file to grow larger than what qtext_load_file can
2106  * (theoretically) handle. This has been seen to be reachable on 32-bit
2107  * platforms.
2108  */
2109  if (unlikely(query_len >= MaxAllocHugeSize - off))
2110  {
2111  errno = EFBIG; /* not quite right, but it'll do */
2112  fd = -1;
2113  goto error;
2114  }
2115 
2116  /* Now write the data into the successfully-reserved part of the file */
2117  fd = OpenTransientFile(PGSS_TEXT_FILE, O_RDWR | O_CREAT | PG_BINARY);
2118  if (fd < 0)
2119  goto error;
2120 
2121  if (pg_pwrite(fd, query, query_len, off) != query_len)
2122  goto error;
2123  if (pg_pwrite(fd, "\0", 1, off + query_len) != 1)
2124  goto error;
2125 
2127 
2128  /* Mark our write complete */
2129  {
2130  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
2131 
2132  SpinLockAcquire(&s->mutex);
2133  s->n_writers--;
2134  SpinLockRelease(&s->mutex);
2135  }
2136 
2137  return true;
2138 
2139 error:
2140  ereport(LOG,
2142  errmsg("could not write file \"%s\": %m",
2143  PGSS_TEXT_FILE)));
2144 
2145  if (fd >= 0)
2147 
2148  /* Mark our write complete */
2149  {
2150  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
2151 
2152  SpinLockAcquire(&s->mutex);
2153  s->n_writers--;
2154  SpinLockRelease(&s->mutex);
2155  }
2156 
2157  return false;
2158 }
2159 
2160 /*
2161  * Read the external query text file into a malloc'd buffer.
2162  *
2163  * Returns NULL (without throwing an error) if unable to read, eg
2164  * file not there or insufficient memory.
2165  *
2166  * On success, the buffer size is also returned into *buffer_size.
2167  *
2168  * This can be called without any lock on pgss->lock, but in that case
2169  * the caller is responsible for verifying that the result is sane.
2170  */
2171 static char *
2172 qtext_load_file(Size *buffer_size)
2173 {
2174  char *buf;
2175  int fd;
2176  struct stat stat;
2177  Size nread;
2178 
2180  if (fd < 0)
2181  {
2182  if (errno != ENOENT)
2183  ereport(LOG,
2185  errmsg("could not read file \"%s\": %m",
2186  PGSS_TEXT_FILE)));
2187  return NULL;
2188  }
2189 
2190  /* Get file length */
2191  if (fstat(fd, &stat))
2192  {
2193  ereport(LOG,
2195  errmsg("could not stat file \"%s\": %m",
2196  PGSS_TEXT_FILE)));
2198  return NULL;
2199  }
2200 
2201  /* Allocate buffer; beware that off_t might be wider than size_t */
2202  if (stat.st_size <= MaxAllocHugeSize)
2203  buf = (char *) malloc(stat.st_size);
2204  else
2205  buf = NULL;
2206  if (buf == NULL)
2207  {
2208  ereport(LOG,
2209  (errcode(ERRCODE_OUT_OF_MEMORY),
2210  errmsg("out of memory"),
2211  errdetail("Could not allocate enough memory to read file \"%s\".",
2212  PGSS_TEXT_FILE)));
2214  return NULL;
2215  }
2216 
2217  /*
2218  * OK, slurp in the file. Windows fails if we try to read more than
2219  * INT_MAX bytes at once, and other platforms might not like that either,
2220  * so read a very large file in 1GB segments.
2221  */
2222  nread = 0;
2223  while (nread < stat.st_size)
2224  {
2225  int toread = Min(1024 * 1024 * 1024, stat.st_size - nread);
2226 
2227  /*
2228  * If we get a short read and errno doesn't get set, the reason is
2229  * probably that garbage collection truncated the file since we did
2230  * the fstat(), so we don't log a complaint --- but we don't return
2231  * the data, either, since it's most likely corrupt due to concurrent
2232  * writes from garbage collection.
2233  */
2234  errno = 0;
2235  if (read(fd, buf + nread, toread) != toread)
2236  {
2237  if (errno)
2238  ereport(LOG,
2240  errmsg("could not read file \"%s\": %m",
2241  PGSS_TEXT_FILE)));
2242  free(buf);
2244  return NULL;
2245  }
2246  nread += toread;
2247  }
2248 
2249  if (CloseTransientFile(fd) != 0)
2250  ereport(LOG,
2252  errmsg("could not close file \"%s\": %m", PGSS_TEXT_FILE)));
2253 
2254  *buffer_size = nread;
2255  return buf;
2256 }
2257 
2258 /*
2259  * Locate a query text in the file image previously read by qtext_load_file().
2260  *
2261  * We validate the given offset/length, and return NULL if bogus. Otherwise,
2262  * the result points to a null-terminated string within the buffer.
2263  */
2264 static char *
2265 qtext_fetch(Size query_offset, int query_len,
2266  char *buffer, Size buffer_size)
2267 {
2268  /* File read failed? */
2269  if (buffer == NULL)
2270  return NULL;
2271  /* Bogus offset/length? */
2272  if (query_len < 0 ||
2273  query_offset + query_len >= buffer_size)
2274  return NULL;
2275  /* As a further sanity check, make sure there's a trailing null */
2276  if (buffer[query_offset + query_len] != '\0')
2277  return NULL;
2278  /* Looks OK */
2279  return buffer + query_offset;
2280 }
2281 
2282 /*
2283  * Do we need to garbage-collect the external query text file?
2284  *
2285  * Caller should hold at least a shared lock on pgss->lock.
2286  */
2287 static bool
2289 {
2290  Size extent;
2291 
2292  /* Read shared extent pointer */
2293  {
2294  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
2295 
2296  SpinLockAcquire(&s->mutex);
2297  extent = s->extent;
2298  SpinLockRelease(&s->mutex);
2299  }
2300 
2301  /*
2302  * Don't proceed if file does not exceed 512 bytes per possible entry.
2303  *
2304  * Here and in the next test, 32-bit machines have overflow hazards if
2305  * pgss_max and/or mean_query_len are large. Force the multiplications
2306  * and comparisons to be done in uint64 arithmetic to forestall trouble.
2307  */
2308  if ((uint64) extent < (uint64) 512 * pgss_max)
2309  return false;
2310 
2311  /*
2312  * Don't proceed if file is less than about 50% bloat. Nothing can or
2313  * should be done in the event of unusually large query texts accounting
2314  * for file's large size. We go to the trouble of maintaining the mean
2315  * query length in order to prevent garbage collection from thrashing
2316  * uselessly.
2317  */
2318  if ((uint64) extent < (uint64) pgss->mean_query_len * pgss_max * 2)
2319  return false;
2320 
2321  return true;
2322 }
2323 
2324 /*
2325  * Garbage-collect orphaned query texts in external file.
2326  *
2327  * This won't be called often in the typical case, since it's likely that
2328  * there won't be too much churn, and besides, a similar compaction process
2329  * occurs when serializing to disk at shutdown or as part of resetting.
2330  * Despite this, it seems prudent to plan for the edge case where the file
2331  * becomes unreasonably large, with no other method of compaction likely to
2332  * occur in the foreseeable future.
2333  *
2334  * The caller must hold an exclusive lock on pgss->lock.
2335  *
2336  * At the first sign of trouble we unlink the query text file to get a clean
2337  * slate (although existing statistics are retained), rather than risk
2338  * thrashing by allowing the same problem case to recur indefinitely.
2339  */
2340 static void
2342 {
2343  char *qbuffer;
2344  Size qbuffer_size;
2345  FILE *qfile = NULL;
2346  HASH_SEQ_STATUS hash_seq;
2347  pgssEntry *entry;
2348  Size extent;
2349  int nentries;
2350 
2351  /*
2352  * When called from pgss_store, some other session might have proceeded
2353  * with garbage collection in the no-lock-held interim of lock strength
2354  * escalation. Check once more that this is actually necessary.
2355  */
2356  if (!need_gc_qtexts())
2357  return;
2358 
2359  /*
2360  * Load the old texts file. If we fail (out of memory, for instance),
2361  * invalidate query texts. Hopefully this is rare. It might seem better
2362  * to leave things alone on an OOM failure, but the problem is that the
2363  * file is only going to get bigger; hoping for a future non-OOM result is
2364  * risky and can easily lead to complete denial of service.
2365  */
2366  qbuffer = qtext_load_file(&qbuffer_size);
2367  if (qbuffer == NULL)
2368  goto gc_fail;
2369 
2370  /*
2371  * We overwrite the query texts file in place, so as to reduce the risk of
2372  * an out-of-disk-space failure. Since the file is guaranteed not to get
2373  * larger, this should always work on traditional filesystems; though we
2374  * could still lose on copy-on-write filesystems.
2375  */
2377  if (qfile == NULL)
2378  {
2379  ereport(LOG,
2381  errmsg("could not write file \"%s\": %m",
2382  PGSS_TEXT_FILE)));
2383  goto gc_fail;
2384  }
2385 
2386  extent = 0;
2387  nentries = 0;
2388 
2389  hash_seq_init(&hash_seq, pgss_hash);
2390  while ((entry = hash_seq_search(&hash_seq)) != NULL)
2391  {
2392  int query_len = entry->query_len;
2393  char *qry = qtext_fetch(entry->query_offset,
2394  query_len,
2395  qbuffer,
2396  qbuffer_size);
2397 
2398  if (qry == NULL)
2399  {
2400  /* Trouble ... drop the text */
2401  entry->query_offset = 0;
2402  entry->query_len = -1;
2403  /* entry will not be counted in mean query length computation */
2404  continue;
2405  }
2406 
2407  if (fwrite(qry, 1, query_len + 1, qfile) != query_len + 1)
2408  {
2409  ereport(LOG,
2411  errmsg("could not write file \"%s\": %m",
2412  PGSS_TEXT_FILE)));
2413  hash_seq_term(&hash_seq);
2414  goto gc_fail;
2415  }
2416 
2417  entry->query_offset = extent;
2418  extent += query_len + 1;
2419  nentries++;
2420  }
2421 
2422  /*
2423  * Truncate away any now-unused space. If this fails for some odd reason,
2424  * we log it, but there's no need to fail.
2425  */
2426  if (ftruncate(fileno(qfile), extent) != 0)
2427  ereport(LOG,
2429  errmsg("could not truncate file \"%s\": %m",
2430  PGSS_TEXT_FILE)));
2431 
2432  if (FreeFile(qfile))
2433  {
2434  ereport(LOG,
2436  errmsg("could not write file \"%s\": %m",
2437  PGSS_TEXT_FILE)));
2438  qfile = NULL;
2439  goto gc_fail;
2440  }
2441 
2442  elog(DEBUG1, "pgss gc of queries file shrunk size from %zu to %zu",
2443  pgss->extent, extent);
2444 
2445  /* Reset the shared extent pointer */
2446  pgss->extent = extent;
2447 
2448  /*
2449  * Also update the mean query length, to be sure that need_gc_qtexts()
2450  * won't still think we have a problem.
2451  */
2452  if (nentries > 0)
2453  pgss->mean_query_len = extent / nentries;
2454  else
2456 
2457  free(qbuffer);
2458 
2459  /*
2460  * OK, count a garbage collection cycle. (Note: even though we have
2461  * exclusive lock on pgss->lock, we must take pgss->mutex for this, since
2462  * other processes may examine gc_count while holding only the mutex.
2463  * Also, we have to advance the count *after* we've rewritten the file,
2464  * else other processes might not realize they read a stale file.)
2465  */
2466  record_gc_qtexts();
2467 
2468  return;
2469 
2470 gc_fail:
2471  /* clean up resources */
2472  if (qfile)
2473  FreeFile(qfile);
2474  free(qbuffer);
2475 
2476  /*
2477  * Since the contents of the external file are now uncertain, mark all
2478  * hashtable entries as having invalid texts.
2479  */
2480  hash_seq_init(&hash_seq, pgss_hash);
2481  while ((entry = hash_seq_search(&hash_seq)) != NULL)
2482  {
2483  entry->query_offset = 0;
2484  entry->query_len = -1;
2485  }
2486 
2487  /*
2488  * Destroy the query text file and create a new, empty one
2489  */
2490  (void) unlink(PGSS_TEXT_FILE);
2492  if (qfile == NULL)
2493  ereport(LOG,
2495  errmsg("could not recreate file \"%s\": %m",
2496  PGSS_TEXT_FILE)));
2497  else
2498  FreeFile(qfile);
2499 
2500  /* Reset the shared extent pointer */
2501  pgss->extent = 0;
2502 
2503  /* Reset mean_query_len to match the new state */
2505 
2506  /*
2507  * Bump the GC count even though we failed.
2508  *
2509  * This is needed to make concurrent readers of file without any lock on
2510  * pgss->lock notice existence of new version of file. Once readers
2511  * subsequently observe a change in GC count with pgss->lock held, that
2512  * forces a safe reopen of file. Writers also require that we bump here,
2513  * of course. (As required by locking protocol, readers and writers don't
2514  * trust earlier file contents until gc_count is found unchanged after
2515  * pgss->lock acquired in shared or exclusive mode respectively.)
2516  */
2517  record_gc_qtexts();
2518 }
2519 
2520 /*
2521  * Release entries corresponding to parameters passed.
2522  */
2523 static void
2524 entry_reset(Oid userid, Oid dbid, uint64 queryid)
2525 {
2526  HASH_SEQ_STATUS hash_seq;
2527  pgssEntry *entry;
2528  FILE *qfile;
2529  long num_entries;
2530  long num_remove = 0;
2531  pgssHashKey key;
2532 
2533  if (!pgss || !pgss_hash)
2534  ereport(ERROR,
2535  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
2536  errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
2537 
2539  num_entries = hash_get_num_entries(pgss_hash);
2540 
2541  if (userid != 0 && dbid != 0 && queryid != UINT64CONST(0))
2542  {
2543  /* If all the parameters are available, use the fast path. */
2544  memset(&key, 0, sizeof(pgssHashKey));
2545  key.userid = userid;
2546  key.dbid = dbid;
2547  key.queryid = queryid;
2548 
2549  /* Remove the key if it exists, starting with the top-level entry */
2550  key.toplevel = false;
2551  entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_REMOVE, NULL);
2552  if (entry) /* found */
2553  num_remove++;
2554 
2555  /* Also remove entries for top level statements */
2556  key.toplevel = true;
2557 
2558  /* Remove the key if exists */
2559  entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_REMOVE, NULL);
2560  if (entry) /* found */
2561  num_remove++;
2562  }
2563  else if (userid != 0 || dbid != 0 || queryid != UINT64CONST(0))
2564  {
2565  /* Remove entries corresponding to valid parameters. */
2566  hash_seq_init(&hash_seq, pgss_hash);
2567  while ((entry = hash_seq_search(&hash_seq)) != NULL)
2568  {
2569  if ((!userid || entry->key.userid == userid) &&
2570  (!dbid || entry->key.dbid == dbid) &&
2571  (!queryid || entry->key.queryid == queryid))
2572  {
2573  hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
2574  num_remove++;
2575  }
2576  }
2577  }
2578  else
2579  {
2580  /* Remove all entries. */
2581  hash_seq_init(&hash_seq, pgss_hash);
2582  while ((entry = hash_seq_search(&hash_seq)) != NULL)
2583  {
2584  hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
2585  num_remove++;
2586  }
2587  }
2588 
2589  /* All entries are removed? */
2590  if (num_entries != num_remove)
2591  goto release_lock;
2592 
2593  /*
2594  * Reset global statistics for pg_stat_statements since all entries are
2595  * removed.
2596  */
2597  {
2598  volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
2599  TimestampTz stats_reset = GetCurrentTimestamp();
2600 
2601  SpinLockAcquire(&s->mutex);
2602  s->stats.dealloc = 0;
2603  s->stats.stats_reset = stats_reset;
2604  SpinLockRelease(&s->mutex);
2605  }
2606 
2607  /*
2608  * Write new empty query file, perhaps even creating a new one to recover
2609  * if the file was missing.
2610  */
2612  if (qfile == NULL)
2613  {
2614  ereport(LOG,
2616  errmsg("could not create file \"%s\": %m",
2617  PGSS_TEXT_FILE)));
2618  goto done;
2619  }
2620 
2621  /* If ftruncate fails, log it, but it's not a fatal problem */
2622  if (ftruncate(fileno(qfile), 0) != 0)
2623  ereport(LOG,
2625  errmsg("could not truncate file \"%s\": %m",
2626  PGSS_TEXT_FILE)));
2627 
2628  FreeFile(qfile);
2629 
2630 done:
2631  pgss->extent = 0;
2632  /* This counts as a query text garbage collection for our purposes */
2633  record_gc_qtexts();
2634 
2635 release_lock:
2637 }
2638 
2639 /*
2640  * Generate a normalized version of the query string that will be used to
2641  * represent all similar queries.
2642  *
2643  * Note that the normalized representation may well vary depending on
2644  * just which "equivalent" query is used to create the hashtable entry.
2645  * We assume this is OK.
2646  *
2647  * If query_loc > 0, then "query" has been advanced by that much compared to
2648  * the original string start, so we need to translate the provided locations
2649  * to compensate. (This lets us avoid re-scanning statements before the one
2650  * of interest, so it's worth doing.)
2651  *
2652  * *query_len_p contains the input string length, and is updated with
2653  * the result string length on exit. The resulting string might be longer
2654  * or shorter depending on what happens with replacement of constants.
2655  *
2656  * Returns a palloc'd string.
2657  */
2658 static char *
2659 generate_normalized_query(JumbleState *jstate, const char *query,
2660  int query_loc, int *query_len_p)
2661 {
2662  char *norm_query;
2663  int query_len = *query_len_p;
2664  int i,
2665  norm_query_buflen, /* Space allowed for norm_query */
2666  len_to_wrt, /* Length (in bytes) to write */
2667  quer_loc = 0, /* Source query byte location */
2668  n_quer_loc = 0, /* Normalized query byte location */
2669  last_off = 0, /* Offset from start for previous tok */
2670  last_tok_len = 0; /* Length (in bytes) of that tok */
2671 
2672  /*
2673  * Get constants' lengths (core system only gives us locations). Note
2674  * this also ensures the items are sorted by location.
2675  */
2676  fill_in_constant_lengths(jstate, query, query_loc);
2677 
2678  /*
2679  * Allow for $n symbols to be longer than the constants they replace.
2680  * Constants must take at least one byte in text form, while a $n symbol
2681  * certainly isn't more than 11 bytes, even if n reaches INT_MAX. We
2682  * could refine that limit based on the max value of n for the current
2683  * query, but it hardly seems worth any extra effort to do so.
2684  */
2685  norm_query_buflen = query_len + jstate->clocations_count * 10;
2686 
2687  /* Allocate result buffer */
2688  norm_query = palloc(norm_query_buflen + 1);
2689 
2690  for (i = 0; i < jstate->clocations_count; i++)
2691  {
2692  int off, /* Offset from start for cur tok */
2693  tok_len; /* Length (in bytes) of that tok */
2694 
2695  off = jstate->clocations[i].location;
2696  /* Adjust recorded location if we're dealing with partial string */
2697  off -= query_loc;
2698 
2699  tok_len = jstate->clocations[i].length;
2700 
2701  if (tok_len < 0)
2702  continue; /* ignore any duplicates */
2703 
2704  /* Copy next chunk (what precedes the next constant) */
2705  len_to_wrt = off - last_off;
2706  len_to_wrt -= last_tok_len;
2707 
2708  Assert(len_to_wrt >= 0);
2709  memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt);
2710  n_quer_loc += len_to_wrt;
2711 
2712  /* And insert a param symbol in place of the constant token */
2713  n_quer_loc += sprintf(norm_query + n_quer_loc, "$%d",
2714  i + 1 + jstate->highest_extern_param_id);
2715 
2716  quer_loc = off + tok_len;
2717  last_off = off;
2718  last_tok_len = tok_len;
2719  }
2720 
2721  /*
2722  * We've copied up until the last ignorable constant. Copy over the
2723  * remaining bytes of the original query string.
2724  */
2725  len_to_wrt = query_len - quer_loc;
2726 
2727  Assert(len_to_wrt >= 0);
2728  memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt);
2729  n_quer_loc += len_to_wrt;
2730 
2731  Assert(n_quer_loc <= norm_query_buflen);
2732  norm_query[n_quer_loc] = '\0';
2733 
2734  *query_len_p = n_quer_loc;
2735  return norm_query;
2736 }
2737 
2738 /*
2739  * Given a valid SQL string and an array of constant-location records,
2740  * fill in the textual lengths of those constants.
2741  *
2742  * The constants may use any allowed constant syntax, such as float literals,
2743  * bit-strings, single-quoted strings and dollar-quoted strings. This is
2744  * accomplished by using the public API for the core scanner.
2745  *
2746  * It is the caller's job to ensure that the string is a valid SQL statement
2747  * with constants at the indicated locations. Since in practice the string
2748  * has already been parsed, and the locations that the caller provides will
2749  * have originated from within the authoritative parser, this should not be
2750  * a problem.
2751  *
2752  * Duplicate constant pointers are possible, and will have their lengths
2753  * marked as '-1', so that they are later ignored. (Actually, we assume the
2754  * lengths were initialized as -1 to start with, and don't change them here.)
2755  *
2756  * If query_loc > 0, then "query" has been advanced by that much compared to
2757  * the original string start, so we need to translate the provided locations
2758  * to compensate. (This lets us avoid re-scanning statements before the one
2759  * of interest, so it's worth doing.)
2760  *
2761  * N.B. There is an assumption that a '-' character at a Const location begins
2762  * a negative numeric constant. This precludes there ever being another
2763  * reason for a constant to start with a '-'.
2764  */
2765 static void
2766 fill_in_constant_lengths(JumbleState *jstate, const char *query,
2767  int query_loc)
2768 {
2769  LocationLen *locs;
2771  core_yy_extra_type yyextra;
2772  core_YYSTYPE yylval;
2773  YYLTYPE yylloc;
2774  int last_loc = -1;
2775  int i;
2776 
2777  /*
2778  * Sort the records by location so that we can process them in order while
2779  * scanning the query text.
2780  */
2781  if (jstate->clocations_count > 1)
2782  qsort(jstate->clocations, jstate->clocations_count,
2783  sizeof(LocationLen), comp_location);
2784  locs = jstate->clocations;
2785 
2786  /* initialize the flex scanner --- should match raw_parser() */
2787  yyscanner = scanner_init(query,
2788  &yyextra,
2789  &ScanKeywords,
2791 
2792  /* we don't want to re-emit any escape string warnings */
2793  yyextra.escape_string_warning = false;
2794 
2795  /* Search for each constant, in sequence */
2796  for (i = 0; i < jstate->clocations_count; i++)
2797  {
2798  int loc = locs[i].location;
2799  int tok;
2800 
2801  /* Adjust recorded location if we're dealing with partial string */
2802  loc -= query_loc;
2803 
2804  Assert(loc >= 0);
2805 
2806  if (loc <= last_loc)
2807  continue; /* Duplicate constant, ignore */
2808 
2809  /* Lex tokens until we find the desired constant */
2810  for (;;)
2811  {
2812  tok = core_yylex(&yylval, &yylloc, yyscanner);
2813 
2814  /* We should not hit end-of-string, but if we do, behave sanely */
2815  if (tok == 0)
2816  break; /* out of inner for-loop */
2817 
2818  /*
2819  * We should find the token position exactly, but if we somehow
2820  * run past it, work with that.
2821  */
2822  if (yylloc >= loc)
2823  {
2824  if (query[loc] == '-')
2825  {
2826  /*
2827  * It's a negative value - this is the one and only case
2828  * where we replace more than a single token.
2829  *
2830  * Do not compensate for the core system's special-case
2831  * adjustment of location to that of the leading '-'
2832  * operator in the event of a negative constant. It is
2833  * also useful for our purposes to start from the minus
2834  * symbol. In this way, queries like "select * from foo
2835  * where bar = 1" and "select * from foo where bar = -2"
2836  * will have identical normalized query strings.
2837  */
2838  tok = core_yylex(&yylval, &yylloc, yyscanner);
2839  if (tok == 0)
2840  break; /* out of inner for-loop */
2841  }
2842 
2843  /*
2844  * We now rely on the assumption that flex has placed a zero
2845  * byte after the text of the current token in scanbuf.
2846  */
2847  locs[i].length = strlen(yyextra.scanbuf + loc);
2848  break; /* out of inner for-loop */
2849  }
2850  }
2851 
2852  /* If we hit end-of-string, give up, leaving remaining lengths -1 */
2853  if (tok == 0)
2854  break;
2855 
2856  last_loc = loc;
2857  }
2858 
2860 }
2861 
2862 /*
2863  * comp_location: comparator for qsorting LocationLen structs by location
2864  */
2865 static int
2866 comp_location(const void *a, const void *b)
2867 {
2868  int l = ((const LocationLen *) a)->location;
2869  int r = ((const LocationLen *) b)->location;
2870 
2871  if (l < r)
2872  return -1;
2873  else if (l > r)
2874  return +1;
2875  else
2876  return 0;
2877 }
bool has_privs_of_role(Oid member, Oid role)
Definition: acl.c:4969
void(* post_parse_analyze_hook_type)(ParseState *pstate, Query *query, JumbleState *jstate)
Definition: analyze.h:22
Datum numeric_in(PG_FUNCTION_ARGS)
Definition: numeric.c:627
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1582
static Datum values[MAXATTR]
Definition: bootstrap.c:156
#define CStringGetTextDatum(s)
Definition: builtins.h:94
unsigned int uint32
Definition: c.h:490
#define Min(x, y)
Definition: c.h:988
#define PG_BINARY_R
Definition: c.h:1262
#define MAXALIGN(LEN)
Definition: c.h:795
signed int int32
Definition: c.h:478
#define Max(x, y)
Definition: c.h:982
#define PG_BINARY
Definition: c.h:1260
#define UINT64_FORMAT
Definition: c.h:533
#define unlikely(x)
Definition: c.h:295
#define PG_BINARY_W
Definition: c.h:1263
size_t Size
Definition: c.h:589
enc
int64 TimestampTz
Definition: timestamp.h:39
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:953
void hash_seq_term(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1507
long hash_get_num_entries(HTAB *hashp)
Definition: dynahash.c:1377
Size hash_estimate_size(long num_entries, Size entrysize)
Definition: dynahash.c:781
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1431
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1421
int errcode_for_file_access(void)
Definition: elog.c:881
int errdetail(const char *fmt,...)
Definition: elog.c:1202
int errcode(int sqlerrcode)
Definition: elog.c:858
int errmsg(const char *fmt,...)
Definition: elog.c:1069
#define LOG
Definition: elog.h:31
#define PG_TRY(...)
Definition: elog.h:370
#define PG_END_TRY(...)
Definition: elog.h:395
#define DEBUG1
Definition: elog.h:30
#define ERROR
Definition: elog.h:39
#define PG_FINALLY(...)
Definition: elog.h:387
#define ereport(elevel,...)
Definition: elog.h:149
ExecutorEnd_hook_type ExecutorEnd_hook
Definition: execMain.c:76
ExecutorFinish_hook_type ExecutorFinish_hook
Definition: execMain.c:75
ExecutorStart_hook_type ExecutorStart_hook
Definition: execMain.c:73
void standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Definition: execMain.c:149
void standard_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, uint64 count, bool execute_once)
Definition: execMain.c:312
ExecutorRun_hook_type ExecutorRun_hook
Definition: execMain.c:74
void standard_ExecutorEnd(QueryDesc *queryDesc)
Definition: execMain.c:471
void standard_ExecutorFinish(QueryDesc *queryDesc)
Definition: execMain.c:411
void(* ExecutorRun_hook_type)(QueryDesc *queryDesc, ScanDirection direction, uint64 count, bool execute_once)
Definition: executor.h:79
void(* ExecutorFinish_hook_type)(QueryDesc *queryDesc)
Definition: executor.h:86
void(* ExecutorStart_hook_type)(QueryDesc *queryDesc, int eflags)
Definition: executor.h:75
void(* ExecutorEnd_hook_type)(QueryDesc *queryDesc)
Definition: executor.h:90
FILE * AllocateFile(const char *name, const char *mode)
Definition: fd.c:2384
int durable_rename(const char *oldfile, const char *newfile, int elevel)
Definition: fd.c:688
int CloseTransientFile(int fd)
Definition: fd.c:2610
int FreeFile(FILE *file)
Definition: fd.c:2582
int OpenTransientFile(const char *fileName, int fileFlags)
Definition: fd.c:2434
Datum Int64GetDatum(int64 X)
Definition: fmgr.c:1779
#define PG_RETURN_VOID()
Definition: fmgr.h:349
#define PG_GETARG_OID(n)
Definition: fmgr.h:275
#define PG_GETARG_INT64(n)
Definition: fmgr.h:283
#define PG_GETARG_BOOL(n)
Definition: fmgr.h:274
#define PG_RETURN_DATUM(x)
Definition: fmgr.h:353
#define DirectFunctionCall3(func, arg1, arg2, arg3)
Definition: fmgr.h:646
#define PG_FUNCTION_ARGS
Definition: fmgr.h:193
void InitMaterializedSRF(FunctionCallInfo fcinfo, bits32 flags)
Definition: funcapi.c:76
TypeFuncClass get_call_result_type(FunctionCallInfo fcinfo, Oid *resultTypeId, TupleDesc *resultTupleDesc)
Definition: funcapi.c:276
@ TYPEFUNC_COMPOSITE
Definition: funcapi.h:149
static Datum HeapTupleGetDatum(const HeapTupleData *tuple)
Definition: funcapi.h:230
bool IsUnderPostmaster
Definition: globals.c:113
Oid MyDatabaseId
Definition: globals.c:89
void DefineCustomEnumVariable(const char *name, const char *short_desc, const char *long_desc, int *valueAddr, int bootValue, const struct config_enum_entry *options, GucContext context, int flags, GucEnumCheckHook check_hook, GucEnumAssignHook assign_hook, GucShowHook show_hook)
Definition: guc.c:5069
void DefineCustomBoolVariable(const char *name, const char *short_desc, const char *long_desc, bool *valueAddr, bool bootValue, GucContext context, int flags, GucBoolCheckHook check_hook, GucBoolAssignHook assign_hook, GucShowHook show_hook)
Definition: guc.c:4958
void MarkGUCPrefixReserved(const char *className)
Definition: guc.c:5105
void DefineCustomIntVariable(const char *name, const char *short_desc, const char *long_desc, int *valueAddr, int bootValue, int minValue, int maxValue, GucContext context, int flags, GucIntCheckHook check_hook, GucIntAssignHook assign_hook, GucShowHook show_hook)
Definition: guc.c:4984
@ PGC_SUSET
Definition: guc.h:74
@ PGC_POSTMASTER
Definition: guc.h:70
@ PGC_SIGHUP
Definition: guc.h:71
#define free(a)
Definition: header.h:65
#define malloc(a)
Definition: header.h:50
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull)
Definition: heaptuple.c:1020
@ HASH_FIND
Definition: hsearch.h:113
@ HASH_REMOVE
Definition: hsearch.h:115
@ HASH_ENTER
Definition: hsearch.h:114
#define HASH_ELEM
Definition: hsearch.h:95
#define HASH_BLOBS
Definition: hsearch.h:97
#define INSTR_TIME_SET_CURRENT(t)
Definition: instr_time.h:122
#define INSTR_TIME_SUBTRACT(x, y)
Definition: instr_time.h:181
#define INSTR_TIME_GET_MILLISEC(t)
Definition: instr_time.h:191
void InstrEndLoop(Instrumentation *instr)
Definition: instrument.c:140
Instrumentation * InstrAlloc(int n, int instrument_options, bool async_mode)
Definition: instrument.c:31
WalUsage pgWalUsage
Definition: instrument.c:22
void WalUsageAccumDiff(WalUsage *dst, const WalUsage *add, const WalUsage *sub)
Definition: instrument.c:280
BufferUsage pgBufferUsage
Definition: instrument.c:20
void BufferUsageAccumDiff(BufferUsage *dst, const BufferUsage *add, const BufferUsage *sub)
Definition: instrument.c:246
@ INSTRUMENT_ALL
Definition: instrument.h:63
#define read(a, b, c)
Definition: win32.h:13
void on_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:361
void(* shmem_startup_hook_type)(void)
Definition: ipc.h:22
shmem_startup_hook_type shmem_startup_hook
Definition: ipci.c:56
void RequestAddinShmemSpace(Size size)
Definition: ipci.c:70
int b
Definition: isn.c:70
int a
Definition: isn.c:69
int i
Definition: isn.c:73
PGDLLIMPORT const ScanKeywordList ScanKeywords
Assert(fmt[strlen(fmt) - 1] !='\n')
LWLockPadded * GetNamedLWLockTranche(const char *tranche_name)
Definition: lwlock.c:597
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1195
void RequestNamedLWLockTranche(const char *tranche_name, int num_lwlocks)
Definition: lwlock.c:693
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
@ LW_SHARED
Definition: lwlock.h:116
@ LW_EXCLUSIVE
Definition: lwlock.h:115
char * pg_any_to_server(const char *s, int len, int encoding)
Definition: mbutils.c:677
int GetDatabaseEncoding(void)
Definition: mbutils.c:1268
void pfree(void *pointer)
Definition: mcxt.c:1436
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1456
void * palloc(Size size)
Definition: mcxt.c:1210
#define MaxAllocHugeSize
Definition: memutils.h:45
void(* shmem_request_hook_type)(void)
Definition: miscadmin.h:488
Oid GetUserId(void)
Definition: miscinit.c:510
shmem_request_hook_type shmem_request_hook
Definition: miscinit.c:1785
bool process_shared_preload_libraries_in_progress
Definition: miscinit.c:1782
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:138
post_parse_analyze_hook_type post_parse_analyze_hook
Definition: analyze.c:60
void * arg
const void size_t len
int32 encoding
Definition: pg_database.h:41
static int entry_cmp(const void *lhs, const void *rhs)
#define PG_STAT_STATEMENTS_COLS_V1_0
static planner_hook_type prev_planner_hook
@ PGSS_V1_9
@ PGSS_V1_10
@ PGSS_V1_1
@ PGSS_V1_3
@ PGSS_V1_2
@ PGSS_V1_8
@ PGSS_V1_0
static int pgss_track
static bool pgss_track_planning
#define ASSUMED_MEDIAN_INIT
#define PG_STAT_STATEMENTS_INFO_COLS
PG_FUNCTION_INFO_V1(pg_stat_statements_reset)
static ExecutorRun_hook_type prev_ExecutorRun
struct pgssSharedState pgssSharedState
static void pgss_store(const char *query, uint64 queryId, int query_location, int query_len, pgssStoreKind kind, double total_time, uint64 rows, const BufferUsage *bufusage, const WalUsage *walusage, const struct JitInstrumentation *jitusage, JumbleState *jstate)
static void pg_stat_statements_internal(FunctionCallInfo fcinfo, pgssVersion api_version, bool showtext)
#define record_gc_qtexts()
Datum pg_stat_statements_reset_1_7(PG_FUNCTION_ARGS)
static PlannedStmt * pgss_planner(Query *parse, const char *query_string, int cursorOptions, ParamListInfo boundParams)
static int exec_nested_level
void _PG_init(void)
static void gc_qtexts(void)
#define PG_STAT_STATEMENTS_COLS_V1_8
static int comp_location(const void *a, const void *b)
#define PG_STAT_STATEMENTS_COLS
struct Counters Counters
Datum pg_stat_statements_1_9(PG_FUNCTION_ARGS)
#define PGSS_TEXT_FILE
PGSSTrackLevel
@ PGSS_TRACK_ALL
@ PGSS_TRACK_NONE
@ PGSS_TRACK_TOP
PG_MODULE_MAGIC
static int plan_nested_level
static char * qtext_fetch(Size query_offset, int query_len, char *buffer, Size buffer_size)
static int pgss_max
#define USAGE_DEALLOC_PERCENT
static bool qtext_store(const char *query, int query_len, Size *query_offset, int *gc_count)
Datum pg_stat_statements_1_10(PG_FUNCTION_ARGS)
#define USAGE_EXEC(duration)
#define STICKY_DECREASE_FACTOR
#define IS_STICKY(c)
static const struct config_enum_entry track_options[]
#define PG_STAT_STATEMENTS_COLS_V1_2
Datum pg_stat_statements_reset(PG_FUNCTION_ARGS)
static void pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString, bool readOnlyTree, ProcessUtilityContext context, ParamListInfo params, QueryEnvironment *queryEnv, DestReceiver *dest, QueryCompletion *qc)
#define PGSS_DUMP_FILE
static char * qtext_load_file(Size *buffer_size)
static post_parse_analyze_hook_type prev_post_parse_analyze_hook
static bool need_gc_qtexts(void)
#define pgss_enabled(level)
static shmem_startup_hook_type prev_shmem_startup_hook
static shmem_request_hook_type prev_shmem_request_hook
static void entry_reset(Oid userid, Oid dbid, uint64 queryid)
static void pgss_shmem_request(void)
pgssStoreKind
@ PGSS_PLAN
@ PGSS_EXEC
@ PGSS_INVALID
@ PGSS_NUMKIND
static void pgss_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, uint64 count, bool execute_once)
#define ASSUMED_LENGTH_INIT
#define PG_STAT_STATEMENTS_COLS_V1_3
static Size pgss_memsize(void)
static bool pgss_save
static void pgss_shmem_startup(void)
struct pgssGlobalStats pgssGlobalStats
static const uint32 PGSS_PG_MAJOR_VERSION
Datum pg_stat_statements_1_2(PG_FUNCTION_ARGS)
struct pgssEntry pgssEntry
#define USAGE_DECREASE_FACTOR
static ExecutorStart_hook_type prev_ExecutorStart
Datum pg_stat_statements(PG_FUNCTION_ARGS)
Datum pg_stat_statements_info(PG_FUNCTION_ARGS)
static void entry_dealloc(void)
#define PG_STAT_STATEMENTS_COLS_V1_10
static pgssSharedState * pgss
Datum pg_stat_statements_1_3(PG_FUNCTION_ARGS)
static void pgss_ExecutorFinish(QueryDesc *queryDesc)
static ProcessUtility_hook_type prev_ProcessUtility
#define PG_STAT_STATEMENTS_COLS_V1_1
Datum pg_stat_statements_1_8(PG_FUNCTION_ARGS)
static void pgss_post_parse_analyze(ParseState *pstate, Query *query, JumbleState *jstate)
struct pgssHashKey pgssHashKey
static pgssEntry * entry_alloc(pgssHashKey *key, Size query_offset, int query_len, int encoding, bool sticky)
static void fill_in_constant_lengths(JumbleState *jstate, const char *query, int query_loc)
static bool pgss_track_utility
#define USAGE_INIT
static ExecutorEnd_hook_type prev_ExecutorEnd
#define PG_STAT_STATEMENTS_COLS_V1_9
#define PGSS_HANDLED_UTILITY(n)
static void pgss_ExecutorEnd(QueryDesc *queryDesc)
static char * generate_normalized_query(JumbleState *jstate, const char *query, int query_loc, int *query_len_p)
static void pgss_ExecutorStart(QueryDesc *queryDesc, int eflags)
static HTAB * pgss_hash
static const uint32 PGSS_FILE_HEADER
static void pgss_shmem_shutdown(int code, Datum arg)
static ExecutorFinish_hook_type prev_ExecutorFinish
static char * buf
Definition: pg_test_fsync.c:67
#define PG_VALID_BE_ENCODING(_enc)
Definition: pg_wchar.h:281
int duration
Definition: pgbench.c:184
static core_yyscan_t yyscanner
Definition: pl_scanner.c:106
planner_hook_type planner_hook
Definition: planner.c:77
PlannedStmt * standard_planner(Query *parse, const char *query_string, int cursorOptions, ParamListInfo boundParams)
Definition: planner.c:286
PlannedStmt *(* planner_hook_type)(Query *parse, const char *query_string, int cursorOptions, ParamListInfo boundParams)
Definition: planner.h:26
#define sprintf
Definition: port.h:240
#define pg_pwrite
Definition: port.h:226
#define snprintf
Definition: port.h:238
#define qsort(a, b, c, d)
Definition: port.h:445
#define Int64GetDatumFast(X)
Definition: postgres.h:554
uintptr_t Datum
Definition: postgres.h:64
#define Float8GetDatumFast(X)
Definition: postgres.h:556
static Datum BoolGetDatum(bool X)
Definition: postgres.h:102
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:252
static Datum CStringGetDatum(const char *X)
Definition: postgres.h:350
static Datum Int32GetDatum(int32 X)
Definition: postgres.h:212
unsigned int Oid
Definition: postgres_ext.h:31
e
Definition: preproc-init.c:82
static int fd(const char *x, int i)
Definition: preproc-init.c:105
const char * CleanQuerytext(const char *query, int *location, int *len)
void EnableQueryId(void)
static struct subre * parse(struct vars *v, int stopper, int type, struct state *init, struct state *final)
Definition: regcomp.c:717
int slock_t
Definition: s_lock.h:754
#define YYLTYPE
Definition: scanner.h:44
core_yyscan_t scanner_init(const char *str, core_yy_extra_type *yyext, const ScanKeywordList *keywordlist, const uint16 *keyword_tokens)
void scanner_finish(core_yyscan_t yyscanner)
PGDLLIMPORT const uint16 ScanKeywordTokens[]
void * core_yyscan_t
Definition: scanner.h:121
int core_yylex(core_YYSTYPE *yylval_param, YYLTYPE *yylloc_param, core_yyscan_t yyscanner)
ScanDirection
Definition: sdir.h:25
Size add_size(Size s1, Size s2)
Definition: shmem.c:502
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:396
HTAB * ShmemInitHash(const char *name, long init_size, long max_size, HASHCTL *infoP, int hash_flags)
Definition: shmem.c:341
#define SpinLockInit(lock)
Definition: spin.h:60
#define SpinLockRelease(lock)
Definition: spin.h:64
#define SpinLockAcquire(lock)
Definition: spin.h:62
static void error(void)
Definition: sql-dyntest.c:147
int64 shared_blks_dirtied
Definition: instrument.h:28
int64 local_blks_hit
Definition: instrument.h:30
instr_time temp_blk_write_time
Definition: instrument.h:39
int64 local_blks_written
Definition: instrument.h:33
instr_time blk_write_time
Definition: instrument.h:37
instr_time temp_blk_read_time
Definition: instrument.h:38
int64 temp_blks_read
Definition: instrument.h:34
int64 shared_blks_read
Definition: instrument.h:27
int64 shared_blks_written
Definition: instrument.h:29
int64 temp_blks_written
Definition: instrument.h:35
instr_time blk_read_time
Definition: instrument.h:36
int64 local_blks_read
Definition: instrument.h:31
int64 local_blks_dirtied
Definition: instrument.h:32
int64 shared_blks_hit
Definition: instrument.h:26
int64 temp_blks_written
int64 calls[PGSS_NUMKIND]
int64 shared_blks_written
double jit_generation_time
int64 temp_blks_read
double min_time[PGSS_NUMKIND]
int64 local_blks_written
double sum_var_time[PGSS_NUMKIND]
double temp_blk_read_time
int64 jit_emission_count
double jit_emission_time
int64 shared_blks_hit
double jit_optimization_time
double blk_read_time
int64 jit_optimization_count
double total_time[PGSS_NUMKIND]
double max_time[PGSS_NUMKIND]
int64 shared_blks_dirtied
double mean_time[PGSS_NUMKIND]
double temp_blk_write_time
int64 local_blks_dirtied
int64 jit_inlining_count
int64 shared_blks_read
int64 local_blks_hit
int64 local_blks_read
double jit_inlining_time
double blk_write_time
uint64 es_processed
Definition: execnodes.h:664
struct JitContext * es_jit
Definition: execnodes.h:706
MemoryContext es_query_cxt
Definition: execnodes.h:660
fmNodePtr resultinfo
Definition: fmgr.h:89
Size keysize
Definition: hsearch.h:75
Size entrysize
Definition: hsearch.h:76
Definition: dynahash.c:220
WalUsage walusage
Definition: instrument.h:90
BufferUsage bufusage
Definition: instrument.h:89
JitInstrumentation instr
Definition: jit.h:61
instr_time generation_counter
Definition: jit.h:33
size_t created_functions
Definition: jit.h:30
instr_time optimization_counter
Definition: jit.h:39
instr_time emission_counter
Definition: jit.h:42
instr_time inlining_counter
Definition: jit.h:36
int highest_extern_param_id
Definition: queryjumble.h:50
LocationLen * clocations
Definition: queryjumble.h:41
int clocations_count
Definition: queryjumble.h:47
Definition: lwlock.h:40
Definition: nodes.h:129
const char * p_sourcetext
Definition: parse_node.h:192
int stmt_location
Definition: plannodes.h:102
int stmt_len
Definition: plannodes.h:103
Node * utilityStmt
Definition: plannodes.h:99
uint64 queryId
Definition: plannodes.h:55
uint64 nprocessed
Definition: cmdtag.h:33
CommandTag commandTag
Definition: cmdtag.h:32
const char * sourceText
Definition: execdesc.h:38
EState * estate
Definition: execdesc.h:48
PlannedStmt * plannedstmt
Definition: execdesc.h:37
struct Instrumentation * totaltime
Definition: execdesc.h:55
int stmt_location
Definition: parsenodes.h:236
Node * utilityStmt
Definition: parsenodes.h:143
TupleDesc setDesc
Definition: execnodes.h:334
Tuplestorestate * setResult
Definition: execnodes.h:333
uint64 wal_bytes
Definition: instrument.h:53
int64 wal_fpi
Definition: instrument.h:52
int64 wal_records
Definition: instrument.h:51
Definition: guc.h:168
bool escape_string_warning
Definition: scanner.h:88
char * scanbuf
Definition: scanner.h:72
Counters counters
pgssHashKey key
TimestampTz stats_reset
pgssGlobalStats stats
__int64 st_size
Definition: win32_port.h:275
void tuplestore_putvalues(Tuplestorestate *state, TupleDesc tdesc, Datum *values, bool *isnull)
Definition: tuplestore.c:750
void standard_ProcessUtility(PlannedStmt *pstmt, const char *queryString, bool readOnlyTree, ProcessUtilityContext context, ParamListInfo params, QueryEnvironment *queryEnv, DestReceiver *dest, QueryCompletion *qc)
Definition: utility.c:547
ProcessUtility_hook_type ProcessUtility_hook
Definition: utility.c:77
void(* ProcessUtility_hook_type)(PlannedStmt *pstmt, const char *queryString, bool readOnlyTree, ProcessUtilityContext context, ParamListInfo params, QueryEnvironment *queryEnv, DestReceiver *dest, QueryCompletion *qc)
Definition: utility.h:71
ProcessUtilityContext
Definition: utility.h:21
static Datum TimestampTzGetDatum(TimestampTz X)
Definition: timestamp.h:52
#define fstat
Definition: win32_port.h:285
#define ftruncate(a, b)
Definition: win32_port.h:82