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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) 2008-2026, 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/htup_details.h"
51 : : #include "access/parallel.h"
52 : : #include "catalog/pg_authid.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 "pgstat.h"
62 : : #include "storage/fd.h"
63 : : #include "storage/ipc.h"
64 : : #include "storage/lwlock.h"
65 : : #include "storage/shmem.h"
66 : : #include "storage/spin.h"
67 : : #include "tcop/utility.h"
68 : : #include "utils/acl.h"
69 : : #include "utils/builtins.h"
70 : : #include "utils/memutils.h"
71 : : #include "utils/timestamp.h"
72 : : #include "utils/tuplestore.h"
73 : :
74 : 10 : PG_MODULE_MAGIC_EXT(
75 : : .name = "pg_stat_statements",
76 : : .version = PG_VERSION
77 : : );
78 : :
79 : : /* Location of permanent stats file (valid when database is shut down) */
80 : : #define PGSS_DUMP_FILE PGSTAT_STAT_PERMANENT_DIRECTORY "/pg_stat_statements.stat"
81 : :
82 : : /*
83 : : * Location of external query text file.
84 : : */
85 : : #define PGSS_TEXT_FILE PG_STAT_TMP_DIR "/pgss_query_texts.stat"
86 : :
87 : : /* Magic number identifying the stats file format */
88 : : static const uint32 PGSS_FILE_HEADER = 0x20250731;
89 : :
90 : : /* PostgreSQL major version number, changes in which invalidate all entries */
91 : : static const uint32 PGSS_PG_MAJOR_VERSION = PG_VERSION_NUM / 100;
92 : :
93 : : /* XXX: Should USAGE_EXEC reflect execution time and/or buffer usage? */
94 : : #define USAGE_EXEC(duration) (1.0)
95 : : #define USAGE_INIT (1.0) /* including initial planning */
96 : : #define ASSUMED_MEDIAN_INIT (10.0) /* initial assumed median usage */
97 : : #define ASSUMED_LENGTH_INIT 1024 /* initial assumed mean query length */
98 : : #define USAGE_DECREASE_FACTOR (0.99) /* decreased every entry_dealloc */
99 : : #define STICKY_DECREASE_FACTOR (0.50) /* factor for sticky entries */
100 : : #define USAGE_DEALLOC_PERCENT 5 /* free this % of entries at once */
101 : : #define IS_STICKY(c) ((c.calls[PGSS_PLAN] + c.calls[PGSS_EXEC]) == 0)
102 : :
103 : : /*
104 : : * Extension version number, for supporting older extension versions' objects
105 : : */
106 : : typedef enum pgssVersion
107 : : {
108 : : PGSS_V1_0 = 0,
109 : : PGSS_V1_1,
110 : : PGSS_V1_2,
111 : : PGSS_V1_3,
112 : : PGSS_V1_8,
113 : : PGSS_V1_9,
114 : : PGSS_V1_10,
115 : : PGSS_V1_11,
116 : : PGSS_V1_12,
117 : : PGSS_V1_13,
118 : : } pgssVersion;
119 : :
120 : : typedef enum pgssStoreKind
121 : : {
122 : : PGSS_INVALID = -1,
123 : :
124 : : /*
125 : : * PGSS_PLAN and PGSS_EXEC must be respectively 0 and 1 as they're used to
126 : : * reference the underlying values in the arrays in the Counters struct,
127 : : * and this order is required in pg_stat_statements_internal().
128 : : */
129 : : PGSS_PLAN = 0,
130 : : PGSS_EXEC,
131 : : } pgssStoreKind;
132 : :
133 : : #define PGSS_NUMKIND (PGSS_EXEC + 1)
134 : :
135 : : /*
136 : : * Hashtable key that defines the identity of a hashtable entry. We separate
137 : : * queries by user and by database even if they are otherwise identical.
138 : : *
139 : : * If you add a new key to this struct, make sure to teach pgss_store() to
140 : : * zero the padding bytes. Otherwise, things will break, because pgss_hash is
141 : : * created using HASH_BLOBS, and thus tag_hash is used to hash this.
142 : : */
143 : : typedef struct pgssHashKey
144 : : {
145 : : Oid userid; /* user OID */
146 : : Oid dbid; /* database OID */
147 : : int64 queryid; /* query identifier */
148 : : bool toplevel; /* query executed at top level */
149 : : } pgssHashKey;
150 : :
151 : : /*
152 : : * The actual stats counters kept within pgssEntry.
153 : : */
154 : : typedef struct Counters
155 : : {
156 : : int64 calls[PGSS_NUMKIND]; /* # of times planned/executed */
157 : : double total_time[PGSS_NUMKIND]; /* total planning/execution time,
158 : : * in msec */
159 : : double min_time[PGSS_NUMKIND]; /* minimum planning/execution time in
160 : : * msec since min/max reset */
161 : : double max_time[PGSS_NUMKIND]; /* maximum planning/execution time in
162 : : * msec since min/max reset */
163 : : double mean_time[PGSS_NUMKIND]; /* mean planning/execution time in
164 : : * msec */
165 : : double sum_var_time[PGSS_NUMKIND]; /* sum of variances in
166 : : * planning/execution time in msec */
167 : : int64 rows; /* total # of retrieved or affected rows */
168 : : int64 shared_blks_hit; /* # of shared buffer hits */
169 : : int64 shared_blks_read; /* # of shared disk blocks read */
170 : : int64 shared_blks_dirtied; /* # of shared disk blocks dirtied */
171 : : int64 shared_blks_written; /* # of shared disk blocks written */
172 : : int64 local_blks_hit; /* # of local buffer hits */
173 : : int64 local_blks_read; /* # of local disk blocks read */
174 : : int64 local_blks_dirtied; /* # of local disk blocks dirtied */
175 : : int64 local_blks_written; /* # of local disk blocks written */
176 : : int64 temp_blks_read; /* # of temp blocks read */
177 : : int64 temp_blks_written; /* # of temp blocks written */
178 : : double shared_blk_read_time; /* time spent reading shared blocks,
179 : : * in msec */
180 : : double shared_blk_write_time; /* time spent writing shared blocks,
181 : : * in msec */
182 : : double local_blk_read_time; /* time spent reading local blocks, in
183 : : * msec */
184 : : double local_blk_write_time; /* time spent writing local blocks, in
185 : : * msec */
186 : : double temp_blk_read_time; /* time spent reading temp blocks, in msec */
187 : : double temp_blk_write_time; /* time spent writing temp blocks, in
188 : : * msec */
189 : : double usage; /* usage factor */
190 : : int64 wal_records; /* # of WAL records generated */
191 : : int64 wal_fpi; /* # of WAL full page images generated */
192 : : uint64 wal_bytes; /* total amount of WAL generated in bytes */
193 : : int64 wal_buffers_full; /* # of times the WAL buffers became full */
194 : : int64 jit_functions; /* total number of JIT functions emitted */
195 : : double jit_generation_time; /* total time to generate jit code */
196 : : int64 jit_inlining_count; /* number of times inlining time has been
197 : : * > 0 */
198 : : double jit_deform_time; /* total time to deform tuples in jit code */
199 : : int64 jit_deform_count; /* number of times deform time has been >
200 : : * 0 */
201 : :
202 : : double jit_inlining_time; /* total time to inline jit code */
203 : : int64 jit_optimization_count; /* number of times optimization time
204 : : * has been > 0 */
205 : : double jit_optimization_time; /* total time to optimize jit code */
206 : : int64 jit_emission_count; /* number of times emission time has been
207 : : * > 0 */
208 : : double jit_emission_time; /* total time to emit jit code */
209 : : int64 parallel_workers_to_launch; /* # of parallel workers planned
210 : : * to be launched */
211 : : int64 parallel_workers_launched; /* # of parallel workers actually
212 : : * launched */
213 : : int64 generic_plan_calls; /* number of calls using a generic plan */
214 : : int64 custom_plan_calls; /* number of calls using a custom plan */
215 : : } Counters;
216 : :
217 : : /*
218 : : * Global statistics for pg_stat_statements
219 : : */
220 : : typedef struct pgssGlobalStats
221 : : {
222 : : int64 dealloc; /* # of times entries were deallocated */
223 : : TimestampTz stats_reset; /* timestamp with all stats reset */
224 : : } pgssGlobalStats;
225 : :
226 : : /*
227 : : * Statistics per statement
228 : : *
229 : : * Note: in event of a failure in garbage collection of the query text file,
230 : : * we reset query_offset to zero and query_len to -1. This will be seen as
231 : : * an invalid state by qtext_fetch().
232 : : */
233 : : typedef struct pgssEntry
234 : : {
235 : : pgssHashKey key; /* hash key of entry - MUST BE FIRST */
236 : : Counters counters; /* the statistics for this query */
237 : : Size query_offset; /* query text offset in external file */
238 : : int query_len; /* # of valid bytes in query string, or -1 */
239 : : int encoding; /* query text encoding */
240 : : TimestampTz stats_since; /* timestamp of entry allocation */
241 : : TimestampTz minmax_stats_since; /* timestamp of last min/max values reset */
242 : : slock_t mutex; /* protects the counters only */
243 : : } pgssEntry;
244 : :
245 : : /*
246 : : * Global shared state
247 : : */
248 : : typedef struct pgssSharedState
249 : : {
250 : : LWLockPadded lock; /* protects hashtable search/modification */
251 : : double cur_median_usage; /* current median usage in hashtable */
252 : : Size mean_query_len; /* current mean entry text length */
253 : : slock_t mutex; /* protects following fields only: */
254 : : Size extent; /* current extent of query file */
255 : : int n_writers; /* number of active writers to query file */
256 : : int gc_count; /* query file garbage collection cycle count */
257 : : pgssGlobalStats stats; /* global statistics for pgss */
258 : : } pgssSharedState;
259 : :
260 : : /* Links to shared memory state */
261 : : static pgssSharedState *pgss;
262 : : static HTAB *pgss_hash;
263 : :
264 : : static void pgss_shmem_request(void *arg);
265 : : static void pgss_shmem_init(void *arg);
266 : :
267 : : static const ShmemCallbacks pgss_shmem_callbacks = {
268 : : .request_fn = pgss_shmem_request,
269 : : .init_fn = pgss_shmem_init,
270 : : };
271 : :
272 : : /*---- Local variables ----*/
273 : :
274 : : /* Current nesting depth of planner/ExecutorRun/ProcessUtility calls */
275 : : static int nesting_level = 0;
276 : :
277 : : /* Saved hook values */
278 : : static post_parse_analyze_hook_type prev_post_parse_analyze_hook = NULL;
279 : : static planner_hook_type prev_planner_hook = NULL;
280 : : static ExecutorStart_hook_type prev_ExecutorStart = NULL;
281 : : static ExecutorRun_hook_type prev_ExecutorRun = NULL;
282 : : static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
283 : : static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
284 : : static ProcessUtility_hook_type prev_ProcessUtility = NULL;
285 : :
286 : : /*---- GUC variables ----*/
287 : :
288 : : typedef enum
289 : : {
290 : : PGSS_TRACK_NONE, /* track no statements */
291 : : PGSS_TRACK_TOP, /* only top level statements */
292 : : PGSS_TRACK_ALL, /* all statements, including nested ones */
293 : : } PGSSTrackLevel;
294 : :
295 : : static const struct config_enum_entry track_options[] =
296 : : {
297 : : {"none", PGSS_TRACK_NONE, false},
298 : : {"top", PGSS_TRACK_TOP, false},
299 : : {"all", PGSS_TRACK_ALL, false},
300 : : {NULL, 0, false}
301 : : };
302 : :
303 : : static int pgss_max = 5000; /* max # statements to track */
304 : : static int pgss_track = PGSS_TRACK_TOP; /* tracking level */
305 : : static bool pgss_track_utility = true; /* whether to track utility commands */
306 : : static bool pgss_track_planning = false; /* whether to track planning
307 : : * duration */
308 : : static bool pgss_save = true; /* whether to save stats across shutdown */
309 : :
310 : : #define pgss_enabled(level) \
311 : : (!IsParallelWorker() && \
312 : : (pgss_track == PGSS_TRACK_ALL || \
313 : : (pgss_track == PGSS_TRACK_TOP && (level) == 0)))
314 : :
315 : : #define record_gc_qtexts() \
316 : : do { \
317 : : SpinLockAcquire(&pgss->mutex); \
318 : : pgss->gc_count++; \
319 : : SpinLockRelease(&pgss->mutex); \
320 : : } while(0)
321 : :
322 : : /*---- Function declarations ----*/
323 : :
324 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
325 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_7);
326 : 21 : PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_11);
327 : 0 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_2);
328 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_3);
329 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_8);
330 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_9);
331 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_10);
332 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_11);
333 : 7 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_12);
334 : 25 : PG_FUNCTION_INFO_V1(pg_stat_statements_1_13);
335 : 0 : PG_FUNCTION_INFO_V1(pg_stat_statements);
336 : 10 : PG_FUNCTION_INFO_V1(pg_stat_statements_info);
337 : :
338 : : static void pgss_shmem_shutdown(int code, Datum arg);
339 : : static void pgss_post_parse_analyze(ParseState *pstate, Query *query,
340 : : const JumbleState *jstate);
341 : : static PlannedStmt *pgss_planner(Query *parse,
342 : : const char *query_string,
343 : : int cursorOptions,
344 : : ParamListInfo boundParams,
345 : : ExplainState *es);
346 : : static void pgss_ExecutorStart(QueryDesc *queryDesc, int eflags);
347 : : static void pgss_ExecutorRun(QueryDesc *queryDesc,
348 : : ScanDirection direction,
349 : : uint64 count);
350 : : static void pgss_ExecutorFinish(QueryDesc *queryDesc);
351 : : static void pgss_ExecutorEnd(QueryDesc *queryDesc);
352 : : static void pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
353 : : bool readOnlyTree,
354 : : ProcessUtilityContext context, ParamListInfo params,
355 : : QueryEnvironment *queryEnv,
356 : : DestReceiver *dest, QueryCompletion *qc);
357 : : static void pgss_store(const char *query, int64 queryId,
358 : : int query_location, int query_len,
359 : : pgssStoreKind kind,
360 : : double total_time, uint64 rows,
361 : : const BufferUsage *bufusage,
362 : : const WalUsage *walusage,
363 : : const struct JitInstrumentation *jitusage,
364 : : const JumbleState *jstate,
365 : : int parallel_workers_to_launch,
366 : : int parallel_workers_launched,
367 : : PlannedStmtOrigin planOrigin);
368 : : static void pg_stat_statements_internal(FunctionCallInfo fcinfo,
369 : : pgssVersion api_version,
370 : : bool showtext);
371 : : static pgssEntry *entry_alloc(pgssHashKey *key, Size query_offset, int query_len,
372 : : int encoding, bool sticky);
373 : : static void entry_dealloc(void);
374 : : static bool qtext_store(const char *query, int query_len,
375 : : Size *query_offset, int *gc_count);
376 : : static char *qtext_load_file(Size *buffer_size);
377 : : static char *qtext_fetch(Size query_offset, int query_len,
378 : : char *buffer, Size buffer_size);
379 : : static bool need_gc_qtexts(void);
380 : : static void gc_qtexts(void);
381 : : static TimestampTz entry_reset(Oid userid, Oid dbid, int64 queryid, bool minmax_only);
382 : : static char *generate_normalized_query(const JumbleState *jstate,
383 : : const char *query,
384 : : int query_loc, int *query_len_p);
385 : :
386 : : /*
387 : : * Module load callback
388 : : */
389 : : void
390 : 10 : _PG_init(void)
391 : : {
392 : : /*
393 : : * In order to create our shared memory area, we have to be loaded via
394 : : * shared_preload_libraries. If not, fall out without hooking into any of
395 : : * the main system. (We don't throw error here because it seems useful to
396 : : * allow the pg_stat_statements functions to be created even when the
397 : : * module isn't active. The functions must protect themselves against
398 : : * being called then, however.)
399 : : */
400 [ + + ]: 10 : if (!process_shared_preload_libraries_in_progress)
401 : 1 : return;
402 : :
403 : : /*
404 : : * Inform the postmaster that we want to enable query_id calculation if
405 : : * compute_query_id is set to auto.
406 : : */
407 : 9 : EnableQueryId();
408 : :
409 : : /*
410 : : * Define (or redefine) custom GUC variables.
411 : : */
412 : 9 : DefineCustomIntVariable("pg_stat_statements.max",
413 : : "Sets the maximum number of statements tracked by pg_stat_statements.",
414 : : NULL,
415 : : &pgss_max,
416 : : 5000,
417 : : 100,
418 : : INT_MAX / 2,
419 : : PGC_POSTMASTER,
420 : : 0,
421 : : NULL,
422 : : NULL,
423 : : NULL);
424 : :
425 : 9 : DefineCustomEnumVariable("pg_stat_statements.track",
426 : : "Selects which statements are tracked by pg_stat_statements.",
427 : : NULL,
428 : : &pgss_track,
429 : : PGSS_TRACK_TOP,
430 : : track_options,
431 : : PGC_SUSET,
432 : : 0,
433 : : NULL,
434 : : NULL,
435 : : NULL);
436 : :
437 : 9 : DefineCustomBoolVariable("pg_stat_statements.track_utility",
438 : : "Selects whether utility commands are tracked by pg_stat_statements.",
439 : : NULL,
440 : : &pgss_track_utility,
441 : : true,
442 : : PGC_SUSET,
443 : : 0,
444 : : NULL,
445 : : NULL,
446 : : NULL);
447 : :
448 : 9 : DefineCustomBoolVariable("pg_stat_statements.track_planning",
449 : : "Selects whether planning duration is tracked by pg_stat_statements.",
450 : : NULL,
451 : : &pgss_track_planning,
452 : : false,
453 : : PGC_SUSET,
454 : : 0,
455 : : NULL,
456 : : NULL,
457 : : NULL);
458 : :
459 : 9 : DefineCustomBoolVariable("pg_stat_statements.save",
460 : : "Save pg_stat_statements statistics across server shutdowns.",
461 : : NULL,
462 : : &pgss_save,
463 : : true,
464 : : PGC_SIGHUP,
465 : : 0,
466 : : NULL,
467 : : NULL,
468 : : NULL);
469 : :
470 : 9 : MarkGUCPrefixReserved("pg_stat_statements");
471 : :
472 : : /*
473 : : * Register our shared memory needs.
474 : : */
475 : 9 : RegisterShmemCallbacks(&pgss_shmem_callbacks);
476 : :
477 : : /*
478 : : * Install hooks.
479 : : */
480 : 9 : prev_post_parse_analyze_hook = post_parse_analyze_hook;
481 : 9 : post_parse_analyze_hook = pgss_post_parse_analyze;
482 : 9 : prev_planner_hook = planner_hook;
483 : 9 : planner_hook = pgss_planner;
484 : 9 : prev_ExecutorStart = ExecutorStart_hook;
485 : 9 : ExecutorStart_hook = pgss_ExecutorStart;
486 : 9 : prev_ExecutorRun = ExecutorRun_hook;
487 : 9 : ExecutorRun_hook = pgss_ExecutorRun;
488 : 9 : prev_ExecutorFinish = ExecutorFinish_hook;
489 : 9 : ExecutorFinish_hook = pgss_ExecutorFinish;
490 : 9 : prev_ExecutorEnd = ExecutorEnd_hook;
491 : 9 : ExecutorEnd_hook = pgss_ExecutorEnd;
492 : 9 : prev_ProcessUtility = ProcessUtility_hook;
493 : 9 : ProcessUtility_hook = pgss_ProcessUtility;
494 : : }
495 : :
496 : : /*
497 : : * shmem request callback: Request shared memory resources.
498 : : *
499 : : * This is called at postmaster startup. Note that the shared memory isn't
500 : : * allocated here yet, this merely register our needs.
501 : : *
502 : : * In EXEC_BACKEND mode, this is also called in each backend, to re-attach to
503 : : * the shared memory area that was already initialized.
504 : : */
505 : : static void
506 : 11 : pgss_shmem_request(void *arg)
507 : : {
508 : 11 : ShmemRequestHash(.name = "pg_stat_statements hash",
509 : : .nelems = pgss_max,
510 : : .hash_info.keysize = sizeof(pgssHashKey),
511 : : .hash_info.entrysize = sizeof(pgssEntry),
512 : : .hash_flags = HASH_ELEM | HASH_BLOBS,
513 : : .ptr = &pgss_hash,
514 : : );
515 : 11 : ShmemRequestStruct(.name = "pg_stat_statements",
516 : : .size = sizeof(pgssSharedState),
517 : : .ptr = (void **) &pgss,
518 : : );
519 : 11 : }
520 : :
521 : : /*
522 : : * shmem init callback: Initialize our shared memory data structures at
523 : : * postmaster startup.
524 : : *
525 : : * Load any pre-existing statistics from file. Also create and load the
526 : : * query-texts file, which is expected to exist (even if empty) while the
527 : : * module is enabled.
528 : : */
529 : : static void
530 : 11 : pgss_shmem_init(void *arg)
531 : : {
532 : : int tranche_id;
533 : 11 : FILE *file = NULL;
534 : 11 : FILE *qfile = NULL;
535 : : uint32 header;
536 : : int32 num;
537 : : int32 pgver;
538 : : int32 i;
539 : : int buffer_size;
540 : 11 : char *buffer = NULL;
541 : :
542 : : /*
543 : : * We already checked that we're loaded from shared_preload_libraries in
544 : : * _PG_init(), so we should not get here after postmaster startup.
545 : : */
546 : : Assert(!IsUnderPostmaster);
547 : :
548 : : /*
549 : : * Initialize the shmem area with no statistics.
550 : : */
551 : 11 : tranche_id = LWLockNewTrancheId("pg_stat_statements");
552 : 11 : LWLockInitialize(&pgss->lock.lock, tranche_id);
553 : 11 : pgss->cur_median_usage = ASSUMED_MEDIAN_INIT;
554 : 11 : pgss->mean_query_len = ASSUMED_LENGTH_INIT;
555 : 11 : SpinLockInit(&pgss->mutex);
556 : 11 : pgss->extent = 0;
557 : 11 : pgss->n_writers = 0;
558 : 11 : pgss->gc_count = 0;
559 : 11 : pgss->stats.dealloc = 0;
560 : 11 : pgss->stats.stats_reset = GetCurrentTimestamp();
561 : :
562 : : /* The hash table must've also been initialized by now */
563 : : Assert(pgss_hash != NULL);
564 : :
565 : : /*
566 : : * Set up a shmem exit hook to dump the statistics to disk on postmaster
567 : : * (or standalone backend) exit.
568 : : */
569 : 11 : on_shmem_exit(pgss_shmem_shutdown, (Datum) 0);
570 : :
571 : : /*
572 : : * Load any pre-existing statistics from file.
573 : : *
574 : : * Note: we don't bother with locks here, because there should be no other
575 : : * processes running when this code is reached.
576 : : */
577 : :
578 : : /* Unlink query text file possibly left over from crash */
579 : 11 : unlink(PGSS_TEXT_FILE);
580 : :
581 : : /* Allocate new query text temp file */
582 : 11 : qfile = AllocateFile(PGSS_TEXT_FILE, PG_BINARY_W);
583 [ - + ]: 11 : if (qfile == NULL)
584 : 0 : goto write_error;
585 : :
586 : : /*
587 : : * If we were told not to load old statistics, we're done. (Note we do
588 : : * not try to unlink any old dump file in this case. This seems a bit
589 : : * questionable but it's the historical behavior.)
590 : : */
591 [ + + ]: 11 : if (!pgss_save)
592 : : {
593 : 1 : FreeFile(qfile);
594 : 11 : return;
595 : : }
596 : :
597 : : /*
598 : : * Attempt to load old statistics from the dump file.
599 : : */
600 : 10 : file = AllocateFile(PGSS_DUMP_FILE, PG_BINARY_R);
601 [ + + ]: 10 : if (file == NULL)
602 : : {
603 [ - + ]: 7 : if (errno != ENOENT)
604 : 0 : goto read_error;
605 : : /* No existing persisted stats file, so we're done */
606 : 7 : FreeFile(qfile);
607 : 7 : return;
608 : : }
609 : :
610 : 3 : buffer_size = 2048;
611 : 3 : buffer = (char *) palloc(buffer_size);
612 : :
613 [ + - + - ]: 6 : if (fread(&header, sizeof(uint32), 1, file) != 1 ||
614 [ - + ]: 6 : fread(&pgver, sizeof(uint32), 1, file) != 1 ||
615 : 3 : fread(&num, sizeof(int32), 1, file) != 1)
616 : 0 : goto read_error;
617 : :
618 [ + - ]: 3 : if (header != PGSS_FILE_HEADER ||
619 [ - + ]: 3 : pgver != PGSS_PG_MAJOR_VERSION)
620 : 0 : goto data_error;
621 : :
622 [ + + ]: 29370 : for (i = 0; i < num; i++)
623 : : {
624 : : pgssEntry temp;
625 : : pgssEntry *entry;
626 : : Size query_offset;
627 : :
628 [ - + ]: 29367 : if (fread(&temp, sizeof(pgssEntry), 1, file) != 1)
629 : 0 : goto read_error;
630 : :
631 : : /* Encoding is the only field we can easily sanity-check */
632 [ + - + - : 29367 : if (!PG_VALID_BE_ENCODING(temp.encoding))
- + ]
633 : 0 : goto data_error;
634 : :
635 : : /* Resize buffer as needed */
636 [ + + ]: 29367 : if (temp.query_len >= buffer_size)
637 : : {
638 : 1 : buffer_size = Max(buffer_size * 2, temp.query_len + 1);
639 : 1 : buffer = repalloc(buffer, buffer_size);
640 : : }
641 : :
642 [ - + ]: 29367 : if (fread(buffer, 1, temp.query_len + 1, file) != temp.query_len + 1)
643 : 0 : goto read_error;
644 : :
645 : : /* Should have a trailing null, but let's make sure */
646 : 29367 : buffer[temp.query_len] = '\0';
647 : :
648 : : /* Skip loading "sticky" entries */
649 [ + + ]: 29367 : if (IS_STICKY(temp.counters))
650 : 800 : continue;
651 : :
652 : : /* Store the query text */
653 : 28567 : query_offset = pgss->extent;
654 [ - + ]: 28567 : if (fwrite(buffer, 1, temp.query_len + 1, qfile) != temp.query_len + 1)
655 : 0 : goto write_error;
656 : 28567 : pgss->extent += temp.query_len + 1;
657 : :
658 : : /* make the hashtable entry (discards old entries if too many) */
659 : 28567 : entry = entry_alloc(&temp.key, query_offset, temp.query_len,
660 : : temp.encoding,
661 : : false);
662 : :
663 : : /* copy in the actual stats */
664 : 28567 : entry->counters = temp.counters;
665 : 28567 : entry->stats_since = temp.stats_since;
666 : 28567 : entry->minmax_stats_since = temp.minmax_stats_since;
667 : : }
668 : :
669 : : /* Read global statistics for pg_stat_statements */
670 [ - + ]: 3 : if (fread(&pgss->stats, sizeof(pgssGlobalStats), 1, file) != 1)
671 : 0 : goto read_error;
672 : :
673 : 3 : pfree(buffer);
674 : 3 : FreeFile(file);
675 : 3 : FreeFile(qfile);
676 : :
677 : : /*
678 : : * Remove the persisted stats file so it's not included in
679 : : * backups/replication standbys, etc. A new file will be written on next
680 : : * shutdown.
681 : : *
682 : : * Note: it's okay if the PGSS_TEXT_FILE is included in a basebackup,
683 : : * because we remove that file on startup; it acts inversely to
684 : : * PGSS_DUMP_FILE, in that it is only supposed to be around when the
685 : : * server is running, whereas PGSS_DUMP_FILE is only supposed to be around
686 : : * when the server is not running. Leaving the file creates no danger of
687 : : * a newly restored database having a spurious record of execution costs,
688 : : * which is what we're really concerned about here.
689 : : */
690 : 3 : unlink(PGSS_DUMP_FILE);
691 : :
692 : 3 : return;
693 : :
694 : 0 : read_error:
695 [ # # ]: 0 : ereport(LOG,
696 : : (errcode_for_file_access(),
697 : : errmsg("could not read file \"%s\": %m",
698 : : PGSS_DUMP_FILE)));
699 : 0 : goto fail;
700 : 0 : data_error:
701 [ # # ]: 0 : ereport(LOG,
702 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
703 : : errmsg("ignoring invalid data in file \"%s\"",
704 : : PGSS_DUMP_FILE)));
705 : 0 : goto fail;
706 : 0 : write_error:
707 [ # # ]: 0 : ereport(LOG,
708 : : (errcode_for_file_access(),
709 : : errmsg("could not write file \"%s\": %m",
710 : : PGSS_TEXT_FILE)));
711 : 0 : fail:
712 [ # # ]: 0 : if (buffer)
713 : 0 : pfree(buffer);
714 [ # # ]: 0 : if (file)
715 : 0 : FreeFile(file);
716 [ # # ]: 0 : if (qfile)
717 : 0 : FreeFile(qfile);
718 : : /* If possible, throw away the bogus file; ignore any error */
719 : 0 : unlink(PGSS_DUMP_FILE);
720 : :
721 : : /*
722 : : * Don't unlink PGSS_TEXT_FILE here; it should always be around while the
723 : : * server is running with pg_stat_statements enabled
724 : : */
725 : : }
726 : :
727 : : /*
728 : : * shmem_shutdown hook: Dump statistics into file.
729 : : *
730 : : * Note: we don't bother with acquiring lock, because there should be no
731 : : * other processes running when this is called.
732 : : */
733 : : static void
734 : 11 : pgss_shmem_shutdown(int code, Datum arg)
735 : : {
736 : : FILE *file;
737 : 11 : char *qbuffer = NULL;
738 : 11 : Size qbuffer_size = 0;
739 : : HASH_SEQ_STATUS hash_seq;
740 : : int32 num_entries;
741 : : pgssEntry *entry;
742 : :
743 : : /* Don't try to dump during a crash. */
744 [ + + ]: 11 : if (code)
745 : 11 : return;
746 : :
747 : : /* Safety check ... shouldn't get here unless shmem is set up. */
748 [ + - - + ]: 9 : if (!pgss || !pgss_hash)
749 : 0 : return;
750 : :
751 : : /* Don't dump if told not to. */
752 [ + + ]: 9 : if (!pgss_save)
753 : 2 : return;
754 : :
755 : 7 : file = AllocateFile(PGSS_DUMP_FILE ".tmp", PG_BINARY_W);
756 [ - + ]: 7 : if (file == NULL)
757 : 0 : goto error;
758 : :
759 [ - + ]: 7 : if (fwrite(&PGSS_FILE_HEADER, sizeof(uint32), 1, file) != 1)
760 : 0 : goto error;
761 [ - + ]: 7 : if (fwrite(&PGSS_PG_MAJOR_VERSION, sizeof(uint32), 1, file) != 1)
762 : 0 : goto error;
763 : 7 : num_entries = hash_get_num_entries(pgss_hash);
764 [ - + ]: 7 : if (fwrite(&num_entries, sizeof(int32), 1, file) != 1)
765 : 0 : goto error;
766 : :
767 : 7 : qbuffer = qtext_load_file(&qbuffer_size);
768 [ - + ]: 7 : if (qbuffer == NULL)
769 : 0 : goto error;
770 : :
771 : : /*
772 : : * When serializing to disk, we store query texts immediately after their
773 : : * entry data. Any orphaned query texts are thereby excluded.
774 : : */
775 : 7 : hash_seq_init(&hash_seq, pgss_hash);
776 [ + + ]: 59022 : while ((entry = hash_seq_search(&hash_seq)) != NULL)
777 : : {
778 : 59015 : int len = entry->query_len;
779 : 59015 : char *qstr = qtext_fetch(entry->query_offset, len,
780 : : qbuffer, qbuffer_size);
781 : :
782 [ - + ]: 59015 : if (qstr == NULL)
783 : 0 : continue; /* Ignore any entries with bogus texts */
784 : :
785 [ + - ]: 59015 : if (fwrite(entry, sizeof(pgssEntry), 1, file) != 1 ||
786 [ - + ]: 59015 : fwrite(qstr, 1, len + 1, file) != len + 1)
787 : : {
788 : : /* note: we assume hash_seq_term won't change errno */
789 : 0 : hash_seq_term(&hash_seq);
790 : 0 : goto error;
791 : : }
792 : : }
793 : :
794 : : /* Dump global statistics for pg_stat_statements */
795 [ - + ]: 7 : if (fwrite(&pgss->stats, sizeof(pgssGlobalStats), 1, file) != 1)
796 : 0 : goto error;
797 : :
798 : 7 : pfree(qbuffer);
799 : 7 : qbuffer = NULL;
800 : :
801 [ - + ]: 7 : if (FreeFile(file))
802 : : {
803 : 0 : file = NULL;
804 : 0 : goto error;
805 : : }
806 : :
807 : : /*
808 : : * Rename file into place, so we atomically replace any old one.
809 : : */
810 : 7 : (void) durable_rename(PGSS_DUMP_FILE ".tmp", PGSS_DUMP_FILE, LOG);
811 : :
812 : : /* Unlink query-texts file; it's not needed while shutdown */
813 : 7 : unlink(PGSS_TEXT_FILE);
814 : :
815 : 7 : return;
816 : :
817 : 0 : error:
818 [ # # ]: 0 : ereport(LOG,
819 : : (errcode_for_file_access(),
820 : : errmsg("could not write file \"%s\": %m",
821 : : PGSS_DUMP_FILE ".tmp")));
822 [ # # ]: 0 : if (qbuffer)
823 : 0 : pfree(qbuffer);
824 [ # # ]: 0 : if (file)
825 : 0 : FreeFile(file);
826 : 0 : unlink(PGSS_DUMP_FILE ".tmp");
827 : 0 : unlink(PGSS_TEXT_FILE);
828 : : }
829 : :
830 : : /*
831 : : * Post-parse-analysis hook: mark query with a queryId
832 : : */
833 : : static void
834 : 85060 : pgss_post_parse_analyze(ParseState *pstate, Query *query, const JumbleState *jstate)
835 : : {
836 [ - + ]: 85060 : if (prev_post_parse_analyze_hook)
837 : 0 : prev_post_parse_analyze_hook(pstate, query, jstate);
838 : :
839 : : /* Safety check... */
840 [ + - + - : 85060 : if (!pgss || !pgss_hash || !pgss_enabled(nesting_level))
+ + + + +
+ + + ]
841 : 13205 : return;
842 : :
843 : : /*
844 : : * If it's EXECUTE, clear the queryId so that stats will accumulate for
845 : : * the underlying PREPARE. But don't do this if we're not tracking
846 : : * utility statements, to avoid messing up another extension that might be
847 : : * tracking them.
848 : : */
849 [ + + ]: 71855 : if (query->utilityStmt)
850 : : {
851 [ + + + + ]: 32351 : if (pgss_track_utility && IsA(query->utilityStmt, ExecuteStmt))
852 : : {
853 : 3376 : query->queryId = INT64CONST(0);
854 : 3376 : return;
855 : : }
856 : : }
857 : :
858 : : /*
859 : : * If query jumbling were able to identify any ignorable constants, we
860 : : * immediately create a hash table entry for the query, so that we can
861 : : * record the normalized form of the query string. If there were no such
862 : : * constants, the normalized string would be the same as the query text
863 : : * anyway, so there's no need for an early entry.
864 : : */
865 [ + - + + ]: 68479 : if (jstate && jstate->clocations_count > 0)
866 : 39354 : pgss_store(pstate->p_sourcetext,
867 : : query->queryId,
868 : : query->stmt_location,
869 : : query->stmt_len,
870 : : PGSS_INVALID,
871 : : 0,
872 : : 0,
873 : : NULL,
874 : : NULL,
875 : : NULL,
876 : : jstate,
877 : : 0,
878 : : 0,
879 : : PLAN_STMT_UNKNOWN);
880 : : }
881 : :
882 : : /*
883 : : * Planner hook: forward to regular planner, but measure planning time
884 : : * if needed.
885 : : */
886 : : static PlannedStmt *
887 : 50939 : pgss_planner(Query *parse,
888 : : const char *query_string,
889 : : int cursorOptions,
890 : : ParamListInfo boundParams,
891 : : ExplainState *es)
892 : : {
893 : : PlannedStmt *result;
894 : :
895 : : /*
896 : : * We can't process the query if no query_string is provided, as
897 : : * pgss_store needs it. We also ignore query without queryid, as it would
898 : : * be treated as a utility statement, which may not be the case.
899 : : */
900 [ + + + + : 50939 : if (pgss_enabled(nesting_level)
+ + + + ]
901 [ + + + - ]: 39653 : && pgss_track_planning && query_string
902 [ + - ]: 150 : && parse->queryId != INT64CONST(0))
903 : 150 : {
904 : : instr_time start;
905 : : instr_time duration;
906 : : BufferUsage bufusage_start,
907 : : bufusage;
908 : : WalUsage walusage_start,
909 : : walusage;
910 : :
911 : : /* We need to track buffer usage as the planner can access them. */
912 : 150 : bufusage_start = pgBufferUsage;
913 : :
914 : : /*
915 : : * Similarly the planner could write some WAL records in some cases
916 : : * (e.g. setting a hint bit with those being WAL-logged)
917 : : */
918 : 150 : walusage_start = pgWalUsage;
919 : 150 : INSTR_TIME_SET_CURRENT(start);
920 : :
921 : 150 : nesting_level++;
922 [ + - ]: 150 : PG_TRY();
923 : : {
924 [ - + ]: 150 : if (prev_planner_hook)
925 : 0 : result = prev_planner_hook(parse, query_string, cursorOptions,
926 : : boundParams, es);
927 : : else
928 : 150 : result = standard_planner(parse, query_string, cursorOptions,
929 : : boundParams, es);
930 : : }
931 : 0 : PG_FINALLY();
932 : : {
933 : 150 : nesting_level--;
934 : : }
935 [ - + ]: 150 : PG_END_TRY();
936 : :
937 : 150 : INSTR_TIME_SET_CURRENT(duration);
938 : 150 : INSTR_TIME_SUBTRACT(duration, start);
939 : :
940 : : /* calc differences of buffer counters. */
941 : 150 : memset(&bufusage, 0, sizeof(BufferUsage));
942 : 150 : BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start);
943 : :
944 : : /* calc differences of WAL counters. */
945 : 150 : memset(&walusage, 0, sizeof(WalUsage));
946 : 150 : WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start);
947 : :
948 : 300 : pgss_store(query_string,
949 : : parse->queryId,
950 : : parse->stmt_location,
951 : : parse->stmt_len,
952 : : PGSS_PLAN,
953 : 150 : INSTR_TIME_GET_MILLISEC(duration),
954 : : 0,
955 : : &bufusage,
956 : : &walusage,
957 : : NULL,
958 : : NULL,
959 : : 0,
960 : : 0,
961 : : result->planOrigin);
962 : : }
963 : : else
964 : : {
965 : : /*
966 : : * Even though we're not tracking plan time for this statement, we
967 : : * must still increment the nesting level, to ensure that functions
968 : : * evaluated during planning are not seen as top-level calls.
969 : : */
970 : 50789 : nesting_level++;
971 [ + + ]: 50789 : PG_TRY();
972 : : {
973 [ - + ]: 50789 : if (prev_planner_hook)
974 : 0 : result = prev_planner_hook(parse, query_string, cursorOptions,
975 : : boundParams, es);
976 : : else
977 : 50789 : result = standard_planner(parse, query_string, cursorOptions,
978 : : boundParams, es);
979 : : }
980 : 788 : PG_FINALLY();
981 : : {
982 : 50789 : nesting_level--;
983 : : }
984 [ + + ]: 50789 : PG_END_TRY();
985 : : }
986 : :
987 : 50151 : return result;
988 : : }
989 : :
990 : : /*
991 : : * ExecutorStart hook: start up tracking if needed
992 : : */
993 : : static void
994 : 61018 : pgss_ExecutorStart(QueryDesc *queryDesc, int eflags)
995 : : {
996 : : /*
997 : : * If query has queryId zero, don't track it. This prevents double
998 : : * counting of optimizable statements that are directly contained in
999 : : * utility statements.
1000 : : */
1001 [ + + + + : 61018 : if (pgss_enabled(nesting_level) && queryDesc->plannedstmt->queryId != INT64CONST(0))
+ + + + +
+ ]
1002 : : {
1003 : : /* Request all summary instrumentation, i.e. timing, buffers and WAL */
1004 : 41834 : queryDesc->query_instr_options |= INSTRUMENT_ALL;
1005 : : }
1006 : :
1007 [ - + ]: 61018 : if (prev_ExecutorStart)
1008 : 0 : prev_ExecutorStart(queryDesc, eflags);
1009 : : else
1010 : 61018 : standard_ExecutorStart(queryDesc, eflags);
1011 : 60731 : }
1012 : :
1013 : : /*
1014 : : * ExecutorRun hook: all we need do is track nesting depth
1015 : : */
1016 : : static void
1017 : 59322 : pgss_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, uint64 count)
1018 : : {
1019 : 59322 : nesting_level++;
1020 [ + + ]: 59322 : PG_TRY();
1021 : : {
1022 [ - + ]: 59322 : if (prev_ExecutorRun)
1023 : 0 : prev_ExecutorRun(queryDesc, direction, count);
1024 : : else
1025 : 59322 : standard_ExecutorRun(queryDesc, direction, count);
1026 : : }
1027 : 3423 : PG_FINALLY();
1028 : : {
1029 : 59322 : nesting_level--;
1030 : : }
1031 [ + + ]: 59322 : PG_END_TRY();
1032 : 55899 : }
1033 : :
1034 : : /*
1035 : : * ExecutorFinish hook: all we need do is track nesting depth
1036 : : */
1037 : : static void
1038 : 53830 : pgss_ExecutorFinish(QueryDesc *queryDesc)
1039 : : {
1040 : 53830 : nesting_level++;
1041 [ + + ]: 53830 : PG_TRY();
1042 : : {
1043 [ - + ]: 53830 : if (prev_ExecutorFinish)
1044 : 0 : prev_ExecutorFinish(queryDesc);
1045 : : else
1046 : 53830 : standard_ExecutorFinish(queryDesc);
1047 : : }
1048 : 182 : PG_FINALLY();
1049 : : {
1050 : 53830 : nesting_level--;
1051 : : }
1052 [ + + ]: 53830 : PG_END_TRY();
1053 : 53648 : }
1054 : :
1055 : : /*
1056 : : * ExecutorEnd hook: store results if needed
1057 : : */
1058 : : static void
1059 : 56795 : pgss_ExecutorEnd(QueryDesc *queryDesc)
1060 : : {
1061 : 56795 : int64 queryId = queryDesc->plannedstmt->queryId;
1062 : :
1063 [ + + + + ]: 56795 : if (queryId != INT64CONST(0) && queryDesc->query_instr &&
1064 [ + - + + : 39870 : pgss_enabled(nesting_level))
+ - + - ]
1065 : : {
1066 : 39870 : pgss_store(queryDesc->sourceText,
1067 : : queryId,
1068 : 39870 : queryDesc->plannedstmt->stmt_location,
1069 : 39870 : queryDesc->plannedstmt->stmt_len,
1070 : : PGSS_EXEC,
1071 : 39870 : INSTR_TIME_GET_MILLISEC(queryDesc->query_instr->total),
1072 : 39870 : queryDesc->estate->es_total_processed,
1073 : 39870 : &queryDesc->query_instr->bufusage,
1074 : 39870 : &queryDesc->query_instr->walusage,
1075 : 0 : queryDesc->estate->es_jit ? &queryDesc->estate->es_jit->instr : NULL,
1076 : : NULL,
1077 : 39870 : queryDesc->estate->es_parallel_workers_to_launch,
1078 : 39870 : queryDesc->estate->es_parallel_workers_launched,
1079 [ - + ]: 39870 : queryDesc->plannedstmt->planOrigin);
1080 : : }
1081 : :
1082 [ - + ]: 56795 : if (prev_ExecutorEnd)
1083 : 0 : prev_ExecutorEnd(queryDesc);
1084 : : else
1085 : 56795 : standard_ExecutorEnd(queryDesc);
1086 : 56795 : }
1087 : :
1088 : : /*
1089 : : * ProcessUtility hook
1090 : : */
1091 : : static void
1092 : 38061 : pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
1093 : : bool readOnlyTree,
1094 : : ProcessUtilityContext context,
1095 : : ParamListInfo params, QueryEnvironment *queryEnv,
1096 : : DestReceiver *dest, QueryCompletion *qc)
1097 : : {
1098 : 38061 : Node *parsetree = pstmt->utilityStmt;
1099 : 38061 : int64 saved_queryId = pstmt->queryId;
1100 : 38061 : int saved_stmt_location = pstmt->stmt_location;
1101 : 38061 : int saved_stmt_len = pstmt->stmt_len;
1102 : 38061 : PlannedStmtOrigin saved_planOrigin = pstmt->planOrigin;
1103 [ + + + - : 38061 : bool enabled = pgss_track_utility && pgss_enabled(nesting_level);
+ + + - +
+ ]
1104 : :
1105 : : /*
1106 : : * Force utility statements to get queryId zero. We do this even in cases
1107 : : * where the statement contains an optimizable statement for which a
1108 : : * queryId could be derived (such as EXPLAIN or DECLARE CURSOR). For such
1109 : : * cases, runtime control will first go through ProcessUtility and then
1110 : : * the executor, and we don't want the executor hooks to do anything,
1111 : : * since we are already measuring the statement's costs at the utility
1112 : : * level.
1113 : : *
1114 : : * Note that this is only done if pg_stat_statements is enabled and
1115 : : * configured to track utility statements, in the unlikely possibility
1116 : : * that user configured another extension to handle utility statements
1117 : : * only.
1118 : : */
1119 [ + + ]: 38061 : if (enabled)
1120 : 32237 : pstmt->queryId = INT64CONST(0);
1121 : :
1122 : : /*
1123 : : * If it's an EXECUTE statement, we don't track it and don't increment the
1124 : : * nesting level. This allows the cycles to be charged to the underlying
1125 : : * PREPARE instead (by the Executor hooks), which is much more useful.
1126 : : *
1127 : : * We also don't track execution of PREPARE. If we did, we would get one
1128 : : * hash table entry for the PREPARE (with hash calculated from the query
1129 : : * string), and then a different one with the same query string (but hash
1130 : : * calculated from the query tree) would be used to accumulate costs of
1131 : : * ensuing EXECUTEs. This would be confusing. Since PREPARE doesn't
1132 : : * actually run the planner (only parse+rewrite), its costs are generally
1133 : : * pretty negligible and it seems okay to just ignore it.
1134 : : */
1135 [ + + ]: 38061 : if (enabled &&
1136 [ + + ]: 32237 : !IsA(parsetree, ExecuteStmt) &&
1137 [ + + ]: 28867 : !IsA(parsetree, PrepareStmt))
1138 : 26031 : {
1139 : : instr_time start;
1140 : : instr_time duration;
1141 : : uint64 rows;
1142 : : BufferUsage bufusage_start,
1143 : : bufusage;
1144 : : WalUsage walusage_start,
1145 : : walusage;
1146 : :
1147 : 28739 : bufusage_start = pgBufferUsage;
1148 : 28739 : walusage_start = pgWalUsage;
1149 : 28739 : INSTR_TIME_SET_CURRENT(start);
1150 : :
1151 : 28739 : nesting_level++;
1152 [ + + ]: 28739 : PG_TRY();
1153 : : {
1154 [ - + ]: 28739 : if (prev_ProcessUtility)
1155 : 0 : prev_ProcessUtility(pstmt, queryString, readOnlyTree,
1156 : : context, params, queryEnv,
1157 : : dest, qc);
1158 : : else
1159 : 28739 : standard_ProcessUtility(pstmt, queryString, readOnlyTree,
1160 : : context, params, queryEnv,
1161 : : dest, qc);
1162 : : }
1163 : 2708 : PG_FINALLY();
1164 : : {
1165 : 28739 : nesting_level--;
1166 : : }
1167 [ + + ]: 28739 : PG_END_TRY();
1168 : :
1169 : : /*
1170 : : * CAUTION: do not access the *pstmt data structure again below here.
1171 : : * If it was a ROLLBACK or similar, that data structure may have been
1172 : : * freed. We must copy everything we still need into local variables,
1173 : : * which we did above.
1174 : : *
1175 : : * For the same reason, we can't risk restoring pstmt->queryId to its
1176 : : * former value, which'd otherwise be a good idea.
1177 : : */
1178 : 26031 : pstmt = NULL;
1179 : :
1180 : 26031 : INSTR_TIME_SET_CURRENT(duration);
1181 : 26031 : INSTR_TIME_SUBTRACT(duration, start);
1182 : :
1183 : : /*
1184 : : * Track the total number of rows retrieved or affected by the utility
1185 : : * statements of COPY, FETCH, CREATE TABLE AS, CREATE MATERIALIZED
1186 : : * VIEW, REFRESH MATERIALIZED VIEW and SELECT INTO.
1187 : : */
1188 [ + + ]: 26028 : rows = (qc && (qc->commandTag == CMDTAG_COPY ||
1189 [ + + ]: 24210 : qc->commandTag == CMDTAG_FETCH ||
1190 [ + + ]: 23946 : qc->commandTag == CMDTAG_SELECT ||
1191 [ + + ]: 23752 : qc->commandTag == CMDTAG_REFRESH_MATERIALIZED_VIEW)) ?
1192 [ + + ]: 52059 : qc->nprocessed : 0;
1193 : :
1194 : : /* calc differences of buffer counters. */
1195 : 26031 : memset(&bufusage, 0, sizeof(BufferUsage));
1196 : 26031 : BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start);
1197 : :
1198 : : /* calc differences of WAL counters. */
1199 : 26031 : memset(&walusage, 0, sizeof(WalUsage));
1200 : 26031 : WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start);
1201 : :
1202 : 26031 : pgss_store(queryString,
1203 : : saved_queryId,
1204 : : saved_stmt_location,
1205 : : saved_stmt_len,
1206 : : PGSS_EXEC,
1207 : 26031 : INSTR_TIME_GET_MILLISEC(duration),
1208 : : rows,
1209 : : &bufusage,
1210 : : &walusage,
1211 : : NULL,
1212 : : NULL,
1213 : : 0,
1214 : : 0,
1215 : : saved_planOrigin);
1216 : : }
1217 : : else
1218 : : {
1219 : : /*
1220 : : * Even though we're not tracking execution time for this statement,
1221 : : * we must still increment the nesting level, to ensure that functions
1222 : : * evaluated within it are not seen as top-level calls. But don't do
1223 : : * so for EXECUTE; that way, when control reaches pgss_planner or
1224 : : * pgss_ExecutorStart, we will treat the costs as top-level if
1225 : : * appropriate. Likewise, don't bump for PREPARE, so that parse
1226 : : * analysis will treat the statement as top-level if appropriate.
1227 : : *
1228 : : * To be absolutely certain we don't mess up the nesting level,
1229 : : * evaluate the bump_level condition just once.
1230 : : */
1231 : 9322 : bool bump_level =
1232 [ + + ]: 15273 : !IsA(parsetree, ExecuteStmt) &&
1233 [ + + ]: 5951 : !IsA(parsetree, PrepareStmt);
1234 : :
1235 [ + + ]: 9322 : if (bump_level)
1236 : 5822 : nesting_level++;
1237 [ + + ]: 9322 : PG_TRY();
1238 : : {
1239 [ - + ]: 9322 : if (prev_ProcessUtility)
1240 : 0 : prev_ProcessUtility(pstmt, queryString, readOnlyTree,
1241 : : context, params, queryEnv,
1242 : : dest, qc);
1243 : : else
1244 : 9322 : standard_ProcessUtility(pstmt, queryString, readOnlyTree,
1245 : : context, params, queryEnv,
1246 : : dest, qc);
1247 : : }
1248 : 139 : PG_FINALLY();
1249 : : {
1250 [ + + ]: 9322 : if (bump_level)
1251 : 5822 : nesting_level--;
1252 : : }
1253 [ + + ]: 9322 : PG_END_TRY();
1254 : : }
1255 : 35214 : }
1256 : :
1257 : : /*
1258 : : * Store some statistics for a statement.
1259 : : *
1260 : : * If jstate is not NULL then we're trying to create an entry for which
1261 : : * we have no statistics as yet; we just want to record the normalized
1262 : : * query string. total_time, rows, bufusage and walusage are ignored in this
1263 : : * case.
1264 : : *
1265 : : * If kind is PGSS_PLAN or PGSS_EXEC, its value is used as the array position
1266 : : * for the arrays in the Counters field.
1267 : : */
1268 : : static void
1269 : 105405 : pgss_store(const char *query, int64 queryId,
1270 : : int query_location, int query_len,
1271 : : pgssStoreKind kind,
1272 : : double total_time, uint64 rows,
1273 : : const BufferUsage *bufusage,
1274 : : const WalUsage *walusage,
1275 : : const struct JitInstrumentation *jitusage,
1276 : : const JumbleState *jstate,
1277 : : int parallel_workers_to_launch,
1278 : : int parallel_workers_launched,
1279 : : PlannedStmtOrigin planOrigin)
1280 : : {
1281 : : pgssHashKey key;
1282 : : pgssEntry *entry;
1283 : 105405 : char *norm_query = NULL;
1284 : 105405 : int encoding = GetDatabaseEncoding();
1285 : :
1286 : : Assert(query != NULL);
1287 : :
1288 : : /* Safety check... */
1289 [ + - - + ]: 105405 : if (!pgss || !pgss_hash)
1290 : 0 : return;
1291 : :
1292 : : /*
1293 : : * Nothing to do if compute_query_id isn't enabled and no other module
1294 : : * computed a query identifier.
1295 : : */
1296 [ - + ]: 105405 : if (queryId == INT64CONST(0))
1297 : 0 : return;
1298 : :
1299 : : /*
1300 : : * Confine our attention to the relevant part of the string, if the query
1301 : : * is a portion of a multi-statement source string, and update query
1302 : : * location and length if needed.
1303 : : */
1304 : 105405 : query = CleanQuerytext(query, &query_location, &query_len);
1305 : :
1306 : : /* Set up key for hashtable search */
1307 : :
1308 : : /* clear padding */
1309 : 105405 : memset(&key, 0, sizeof(pgssHashKey));
1310 : :
1311 : 105405 : key.userid = GetUserId();
1312 : 105405 : key.dbid = MyDatabaseId;
1313 : 105405 : key.queryid = queryId;
1314 : 105405 : key.toplevel = (nesting_level == 0);
1315 : :
1316 : : /* Lookup the hash table entry with shared lock. */
1317 : 105405 : LWLockAcquire(&pgss->lock.lock, LW_SHARED);
1318 : :
1319 : 105405 : entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
1320 : :
1321 : : /* Create new entry, if not present */
1322 [ + + ]: 105405 : if (!entry)
1323 : : {
1324 : : Size query_offset;
1325 : : int gc_count;
1326 : : bool stored;
1327 : : bool do_gc;
1328 : :
1329 : : /*
1330 : : * Create a new, normalized query string if caller asked. We don't
1331 : : * need to hold the lock while doing this work. (Note: in any case,
1332 : : * it's possible that someone else creates a duplicate hashtable entry
1333 : : * in the interval where we don't hold the lock below. That case is
1334 : : * handled by entry_alloc.)
1335 : : */
1336 [ + + ]: 31377 : if (jstate)
1337 : : {
1338 : 11660 : LWLockRelease(&pgss->lock.lock);
1339 : 11660 : norm_query = generate_normalized_query(jstate, query,
1340 : : query_location,
1341 : : &query_len);
1342 : 11660 : LWLockAcquire(&pgss->lock.lock, LW_SHARED);
1343 : : }
1344 : :
1345 : : /* Append new query text to file with only shared lock held */
1346 [ + + ]: 31377 : stored = qtext_store(norm_query ? norm_query : query, query_len,
1347 : : &query_offset, &gc_count);
1348 : :
1349 : : /*
1350 : : * Determine whether we need to garbage collect external query texts
1351 : : * while the shared lock is still held. This micro-optimization
1352 : : * avoids taking the time to decide this while holding exclusive lock.
1353 : : */
1354 : 31377 : do_gc = need_gc_qtexts();
1355 : :
1356 : : /* Need exclusive lock to make a new hashtable entry - promote */
1357 : 31377 : LWLockRelease(&pgss->lock.lock);
1358 : 31377 : LWLockAcquire(&pgss->lock.lock, LW_EXCLUSIVE);
1359 : :
1360 : : /*
1361 : : * A garbage collection may have occurred while we weren't holding the
1362 : : * lock. In the unlikely event that this happens, the query text we
1363 : : * stored above will have been garbage collected, so write it again.
1364 : : * This should be infrequent enough that doing it while holding
1365 : : * exclusive lock isn't a performance problem.
1366 : : */
1367 [ + - - + ]: 31377 : if (!stored || pgss->gc_count != gc_count)
1368 [ # # ]: 0 : stored = qtext_store(norm_query ? norm_query : query, query_len,
1369 : : &query_offset, NULL);
1370 : :
1371 : : /* If we failed to write to the text file, give up */
1372 [ - + ]: 31377 : if (!stored)
1373 : 0 : goto done;
1374 : :
1375 : : /* OK to create a new hashtable entry */
1376 : 31377 : entry = entry_alloc(&key, query_offset, query_len, encoding,
1377 : : jstate != NULL);
1378 : :
1379 : : /* If needed, perform garbage collection while exclusive lock held */
1380 [ - + ]: 31377 : if (do_gc)
1381 : 0 : gc_qtexts();
1382 : : }
1383 : :
1384 : : /* Increment the counts, except when jstate is not NULL */
1385 [ + + ]: 105405 : if (!jstate)
1386 : : {
1387 : : Assert(kind == PGSS_PLAN || kind == PGSS_EXEC);
1388 : :
1389 : : /*
1390 : : * Grab the spinlock while updating the counters (see comment about
1391 : : * locking rules at the head of the file)
1392 : : */
1393 : 66051 : SpinLockAcquire(&entry->mutex);
1394 : :
1395 : : /* "Unstick" entry if it was previously sticky */
1396 [ + + ]: 66051 : if (IS_STICKY(entry->counters))
1397 : 30544 : entry->counters.usage = USAGE_INIT;
1398 : :
1399 : 66051 : entry->counters.calls[kind] += 1;
1400 : 66051 : entry->counters.total_time[kind] += total_time;
1401 : :
1402 [ + + ]: 66051 : if (entry->counters.calls[kind] == 1)
1403 : : {
1404 : 30638 : entry->counters.min_time[kind] = total_time;
1405 : 30638 : entry->counters.max_time[kind] = total_time;
1406 : 30638 : entry->counters.mean_time[kind] = total_time;
1407 : : }
1408 : : else
1409 : : {
1410 : : /*
1411 : : * Welford's method for accurately computing variance. See
1412 : : * <http://www.johndcook.com/blog/standard_deviation/>
1413 : : */
1414 : 35413 : double old_mean = entry->counters.mean_time[kind];
1415 : :
1416 : 35413 : entry->counters.mean_time[kind] +=
1417 : 35413 : (total_time - old_mean) / entry->counters.calls[kind];
1418 : 35413 : entry->counters.sum_var_time[kind] +=
1419 : 35413 : (total_time - old_mean) * (total_time - entry->counters.mean_time[kind]);
1420 : :
1421 : : /*
1422 : : * Calculate min and max time. min = 0 and max = 0 means that the
1423 : : * min/max statistics were reset
1424 : : */
1425 [ + + ]: 35413 : if (entry->counters.min_time[kind] == 0
1426 [ + + ]: 6 : && entry->counters.max_time[kind] == 0)
1427 : : {
1428 : 3 : entry->counters.min_time[kind] = total_time;
1429 : 3 : entry->counters.max_time[kind] = total_time;
1430 : : }
1431 : : else
1432 : : {
1433 [ + + ]: 35410 : if (entry->counters.min_time[kind] > total_time)
1434 : 6708 : entry->counters.min_time[kind] = total_time;
1435 [ + + ]: 35410 : if (entry->counters.max_time[kind] < total_time)
1436 : 3675 : entry->counters.max_time[kind] = total_time;
1437 : : }
1438 : : }
1439 : 66051 : entry->counters.rows += rows;
1440 : 66051 : entry->counters.shared_blks_hit += bufusage->shared_blks_hit;
1441 : 66051 : entry->counters.shared_blks_read += bufusage->shared_blks_read;
1442 : 66051 : entry->counters.shared_blks_dirtied += bufusage->shared_blks_dirtied;
1443 : 66051 : entry->counters.shared_blks_written += bufusage->shared_blks_written;
1444 : 66051 : entry->counters.local_blks_hit += bufusage->local_blks_hit;
1445 : 66051 : entry->counters.local_blks_read += bufusage->local_blks_read;
1446 : 66051 : entry->counters.local_blks_dirtied += bufusage->local_blks_dirtied;
1447 : 66051 : entry->counters.local_blks_written += bufusage->local_blks_written;
1448 : 66051 : entry->counters.temp_blks_read += bufusage->temp_blks_read;
1449 : 66051 : entry->counters.temp_blks_written += bufusage->temp_blks_written;
1450 : 66051 : entry->counters.shared_blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->shared_blk_read_time);
1451 : 66051 : entry->counters.shared_blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->shared_blk_write_time);
1452 : 66051 : entry->counters.local_blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->local_blk_read_time);
1453 : 66051 : entry->counters.local_blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->local_blk_write_time);
1454 : 66051 : entry->counters.temp_blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->temp_blk_read_time);
1455 : 66051 : entry->counters.temp_blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->temp_blk_write_time);
1456 : 66051 : entry->counters.usage += USAGE_EXEC(total_time);
1457 : 66051 : entry->counters.wal_records += walusage->wal_records;
1458 : 66051 : entry->counters.wal_fpi += walusage->wal_fpi;
1459 : 66051 : entry->counters.wal_bytes += walusage->wal_bytes;
1460 : 66051 : entry->counters.wal_buffers_full += walusage->wal_buffers_full;
1461 [ - + ]: 66051 : if (jitusage)
1462 : : {
1463 : 0 : entry->counters.jit_functions += jitusage->created_functions;
1464 : 0 : entry->counters.jit_generation_time += INSTR_TIME_GET_MILLISEC(jitusage->generation_counter);
1465 : :
1466 [ # # ]: 0 : if (INSTR_TIME_GET_MILLISEC(jitusage->deform_counter))
1467 : 0 : entry->counters.jit_deform_count++;
1468 : 0 : entry->counters.jit_deform_time += INSTR_TIME_GET_MILLISEC(jitusage->deform_counter);
1469 : :
1470 [ # # ]: 0 : if (INSTR_TIME_GET_MILLISEC(jitusage->inlining_counter))
1471 : 0 : entry->counters.jit_inlining_count++;
1472 : 0 : entry->counters.jit_inlining_time += INSTR_TIME_GET_MILLISEC(jitusage->inlining_counter);
1473 : :
1474 [ # # ]: 0 : if (INSTR_TIME_GET_MILLISEC(jitusage->optimization_counter))
1475 : 0 : entry->counters.jit_optimization_count++;
1476 : 0 : entry->counters.jit_optimization_time += INSTR_TIME_GET_MILLISEC(jitusage->optimization_counter);
1477 : :
1478 [ # # ]: 0 : if (INSTR_TIME_GET_MILLISEC(jitusage->emission_counter))
1479 : 0 : entry->counters.jit_emission_count++;
1480 : 0 : entry->counters.jit_emission_time += INSTR_TIME_GET_MILLISEC(jitusage->emission_counter);
1481 : : }
1482 : :
1483 : : /* parallel worker counters */
1484 : 66051 : entry->counters.parallel_workers_to_launch += parallel_workers_to_launch;
1485 : 66051 : entry->counters.parallel_workers_launched += parallel_workers_launched;
1486 : :
1487 : : /* plan cache counters */
1488 [ + + ]: 66051 : if (planOrigin == PLAN_STMT_CACHE_GENERIC)
1489 : 3153 : entry->counters.generic_plan_calls++;
1490 [ + + ]: 62898 : else if (planOrigin == PLAN_STMT_CACHE_CUSTOM)
1491 : 395 : entry->counters.custom_plan_calls++;
1492 : :
1493 : 66051 : SpinLockRelease(&entry->mutex);
1494 : : }
1495 : :
1496 : 39354 : done:
1497 : 105405 : LWLockRelease(&pgss->lock.lock);
1498 : :
1499 : : /* We postpone this clean-up until we're out of the lock */
1500 [ + + ]: 105405 : if (norm_query)
1501 : 11660 : pfree(norm_query);
1502 : : }
1503 : :
1504 : : /*
1505 : : * Reset statement statistics corresponding to userid, dbid, and queryid.
1506 : : */
1507 : : Datum
1508 : 1 : pg_stat_statements_reset_1_7(PG_FUNCTION_ARGS)
1509 : : {
1510 : : Oid userid;
1511 : : Oid dbid;
1512 : : int64 queryid;
1513 : :
1514 : 1 : userid = PG_GETARG_OID(0);
1515 : 1 : dbid = PG_GETARG_OID(1);
1516 : 1 : queryid = PG_GETARG_INT64(2);
1517 : :
1518 : 1 : entry_reset(userid, dbid, queryid, false);
1519 : :
1520 : 1 : PG_RETURN_VOID();
1521 : : }
1522 : :
1523 : : Datum
1524 : 120 : pg_stat_statements_reset_1_11(PG_FUNCTION_ARGS)
1525 : : {
1526 : : Oid userid;
1527 : : Oid dbid;
1528 : : int64 queryid;
1529 : : bool minmax_only;
1530 : :
1531 : 120 : userid = PG_GETARG_OID(0);
1532 : 120 : dbid = PG_GETARG_OID(1);
1533 : 120 : queryid = PG_GETARG_INT64(2);
1534 : 120 : minmax_only = PG_GETARG_BOOL(3);
1535 : :
1536 : 120 : PG_RETURN_TIMESTAMPTZ(entry_reset(userid, dbid, queryid, minmax_only));
1537 : : }
1538 : :
1539 : : /*
1540 : : * Reset statement statistics.
1541 : : */
1542 : : Datum
1543 : 1 : pg_stat_statements_reset(PG_FUNCTION_ARGS)
1544 : : {
1545 : 1 : entry_reset(0, 0, 0, false);
1546 : :
1547 : 1 : PG_RETURN_VOID();
1548 : : }
1549 : :
1550 : : /* Number of output arguments (columns) for various API versions */
1551 : : #define PG_STAT_STATEMENTS_COLS_V1_0 14
1552 : : #define PG_STAT_STATEMENTS_COLS_V1_1 18
1553 : : #define PG_STAT_STATEMENTS_COLS_V1_2 19
1554 : : #define PG_STAT_STATEMENTS_COLS_V1_3 23
1555 : : #define PG_STAT_STATEMENTS_COLS_V1_8 32
1556 : : #define PG_STAT_STATEMENTS_COLS_V1_9 33
1557 : : #define PG_STAT_STATEMENTS_COLS_V1_10 43
1558 : : #define PG_STAT_STATEMENTS_COLS_V1_11 49
1559 : : #define PG_STAT_STATEMENTS_COLS_V1_12 52
1560 : : #define PG_STAT_STATEMENTS_COLS_V1_13 54
1561 : : #define PG_STAT_STATEMENTS_COLS 54 /* maximum of above */
1562 : :
1563 : : /*
1564 : : * Retrieve statement statistics.
1565 : : *
1566 : : * The SQL API of this function has changed multiple times, and will likely
1567 : : * do so again in future. To support the case where a newer version of this
1568 : : * loadable module is being used with an old SQL declaration of the function,
1569 : : * we continue to support the older API versions. For 1.2 and later, the
1570 : : * expected API version is identified by embedding it in the C name of the
1571 : : * function. Unfortunately we weren't bright enough to do that for 1.1.
1572 : : */
1573 : : Datum
1574 : 130 : pg_stat_statements_1_13(PG_FUNCTION_ARGS)
1575 : : {
1576 : 130 : bool showtext = PG_GETARG_BOOL(0);
1577 : :
1578 : 130 : pg_stat_statements_internal(fcinfo, PGSS_V1_13, showtext);
1579 : :
1580 : 130 : return (Datum) 0;
1581 : : }
1582 : :
1583 : : Datum
1584 : 1 : pg_stat_statements_1_12(PG_FUNCTION_ARGS)
1585 : : {
1586 : 1 : bool showtext = PG_GETARG_BOOL(0);
1587 : :
1588 : 1 : pg_stat_statements_internal(fcinfo, PGSS_V1_12, showtext);
1589 : :
1590 : 1 : return (Datum) 0;
1591 : : }
1592 : :
1593 : : Datum
1594 : 1 : pg_stat_statements_1_11(PG_FUNCTION_ARGS)
1595 : : {
1596 : 1 : bool showtext = PG_GETARG_BOOL(0);
1597 : :
1598 : 1 : pg_stat_statements_internal(fcinfo, PGSS_V1_11, showtext);
1599 : :
1600 : 1 : return (Datum) 0;
1601 : : }
1602 : :
1603 : : Datum
1604 : 1 : pg_stat_statements_1_10(PG_FUNCTION_ARGS)
1605 : : {
1606 : 1 : bool showtext = PG_GETARG_BOOL(0);
1607 : :
1608 : 1 : pg_stat_statements_internal(fcinfo, PGSS_V1_10, showtext);
1609 : :
1610 : 1 : return (Datum) 0;
1611 : : }
1612 : :
1613 : : Datum
1614 : 1 : pg_stat_statements_1_9(PG_FUNCTION_ARGS)
1615 : : {
1616 : 1 : bool showtext = PG_GETARG_BOOL(0);
1617 : :
1618 : 1 : pg_stat_statements_internal(fcinfo, PGSS_V1_9, showtext);
1619 : :
1620 : 1 : return (Datum) 0;
1621 : : }
1622 : :
1623 : : Datum
1624 : 1 : pg_stat_statements_1_8(PG_FUNCTION_ARGS)
1625 : : {
1626 : 1 : bool showtext = PG_GETARG_BOOL(0);
1627 : :
1628 : 1 : pg_stat_statements_internal(fcinfo, PGSS_V1_8, showtext);
1629 : :
1630 : 1 : return (Datum) 0;
1631 : : }
1632 : :
1633 : : Datum
1634 : 1 : pg_stat_statements_1_3(PG_FUNCTION_ARGS)
1635 : : {
1636 : 1 : bool showtext = PG_GETARG_BOOL(0);
1637 : :
1638 : 1 : pg_stat_statements_internal(fcinfo, PGSS_V1_3, showtext);
1639 : :
1640 : 1 : return (Datum) 0;
1641 : : }
1642 : :
1643 : : Datum
1644 : 0 : pg_stat_statements_1_2(PG_FUNCTION_ARGS)
1645 : : {
1646 : 0 : bool showtext = PG_GETARG_BOOL(0);
1647 : :
1648 : 0 : pg_stat_statements_internal(fcinfo, PGSS_V1_2, showtext);
1649 : :
1650 : 0 : return (Datum) 0;
1651 : : }
1652 : :
1653 : : /*
1654 : : * Legacy entry point for pg_stat_statements() API versions 1.0 and 1.1.
1655 : : * This can be removed someday, perhaps.
1656 : : */
1657 : : Datum
1658 : 0 : pg_stat_statements(PG_FUNCTION_ARGS)
1659 : : {
1660 : : /* If it's really API 1.1, we'll figure that out below */
1661 : 0 : pg_stat_statements_internal(fcinfo, PGSS_V1_0, true);
1662 : :
1663 : 0 : return (Datum) 0;
1664 : : }
1665 : :
1666 : : /* Common code for all versions of pg_stat_statements() */
1667 : : static void
1668 : 136 : pg_stat_statements_internal(FunctionCallInfo fcinfo,
1669 : : pgssVersion api_version,
1670 : : bool showtext)
1671 : : {
1672 : 136 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
1673 : 136 : Oid userid = GetUserId();
1674 : 136 : bool is_allowed_role = false;
1675 : 136 : char *qbuffer = NULL;
1676 : 136 : Size qbuffer_size = 0;
1677 : 136 : Size extent = 0;
1678 : 136 : int gc_count = 0;
1679 : : HASH_SEQ_STATUS hash_seq;
1680 : : pgssEntry *entry;
1681 : :
1682 : : /*
1683 : : * Superusers or roles with the privileges of pg_read_all_stats members
1684 : : * are allowed
1685 : : */
1686 : 136 : is_allowed_role = has_privs_of_role(userid, ROLE_PG_READ_ALL_STATS);
1687 : :
1688 : : /* hash table must exist already */
1689 [ + - - + ]: 136 : if (!pgss || !pgss_hash)
1690 [ # # ]: 0 : ereport(ERROR,
1691 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1692 : : errmsg("pg_stat_statements must be loaded via \"shared_preload_libraries\"")));
1693 : :
1694 : 136 : InitMaterializedSRF(fcinfo, 0);
1695 : :
1696 : : /*
1697 : : * Check we have the expected number of output arguments. Aside from
1698 : : * being a good safety check, we need a kluge here to detect API version
1699 : : * 1.1, which was wedged into the code in an ill-considered way.
1700 : : */
1701 [ - - - + : 136 : switch (rsinfo->setDesc->natts)
+ + + + +
+ - ]
1702 : : {
1703 : 0 : case PG_STAT_STATEMENTS_COLS_V1_0:
1704 [ # # ]: 0 : if (api_version != PGSS_V1_0)
1705 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1706 : 0 : break;
1707 : 0 : case PG_STAT_STATEMENTS_COLS_V1_1:
1708 : : /* pg_stat_statements() should have told us 1.0 */
1709 [ # # ]: 0 : if (api_version != PGSS_V1_0)
1710 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1711 : 0 : api_version = PGSS_V1_1;
1712 : 0 : break;
1713 : 0 : case PG_STAT_STATEMENTS_COLS_V1_2:
1714 [ # # ]: 0 : if (api_version != PGSS_V1_2)
1715 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1716 : 0 : break;
1717 : 1 : case PG_STAT_STATEMENTS_COLS_V1_3:
1718 [ - + ]: 1 : if (api_version != PGSS_V1_3)
1719 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1720 : 1 : break;
1721 : 1 : case PG_STAT_STATEMENTS_COLS_V1_8:
1722 [ - + ]: 1 : if (api_version != PGSS_V1_8)
1723 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1724 : 1 : break;
1725 : 1 : case PG_STAT_STATEMENTS_COLS_V1_9:
1726 [ - + ]: 1 : if (api_version != PGSS_V1_9)
1727 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1728 : 1 : break;
1729 : 1 : case PG_STAT_STATEMENTS_COLS_V1_10:
1730 [ - + ]: 1 : if (api_version != PGSS_V1_10)
1731 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1732 : 1 : break;
1733 : 1 : case PG_STAT_STATEMENTS_COLS_V1_11:
1734 [ - + ]: 1 : if (api_version != PGSS_V1_11)
1735 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1736 : 1 : break;
1737 : 1 : case PG_STAT_STATEMENTS_COLS_V1_12:
1738 [ - + ]: 1 : if (api_version != PGSS_V1_12)
1739 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1740 : 1 : break;
1741 : 130 : case PG_STAT_STATEMENTS_COLS_V1_13:
1742 [ - + ]: 130 : if (api_version != PGSS_V1_13)
1743 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1744 : 130 : break;
1745 : 0 : default:
1746 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
1747 : : }
1748 : :
1749 : : /*
1750 : : * We'd like to load the query text file (if needed) while not holding any
1751 : : * lock on pgss->lock. In the worst case we'll have to do this again
1752 : : * after we have the lock, but it's unlikely enough to make this a win
1753 : : * despite occasional duplicated work. We need to reload if anybody
1754 : : * writes to the file (either a retail qtext_store(), or a garbage
1755 : : * collection) between this point and where we've gotten shared lock. If
1756 : : * a qtext_store is actually in progress when we look, we might as well
1757 : : * skip the speculative load entirely.
1758 : : */
1759 [ + - ]: 136 : if (showtext)
1760 : : {
1761 : : int n_writers;
1762 : :
1763 : : /* Take the mutex so we can examine variables */
1764 : 136 : SpinLockAcquire(&pgss->mutex);
1765 : 136 : extent = pgss->extent;
1766 : 136 : n_writers = pgss->n_writers;
1767 : 136 : gc_count = pgss->gc_count;
1768 : 136 : SpinLockRelease(&pgss->mutex);
1769 : :
1770 : : /* No point in loading file now if there are active writers */
1771 [ + - ]: 136 : if (n_writers == 0)
1772 : 136 : qbuffer = qtext_load_file(&qbuffer_size);
1773 : : }
1774 : :
1775 : : /*
1776 : : * Get shared lock, load or reload the query text file if we must, and
1777 : : * iterate over the hashtable entries.
1778 : : *
1779 : : * With a large hash table, we might be holding the lock rather longer
1780 : : * than one could wish. However, this only blocks creation of new hash
1781 : : * table entries, and the larger the hash table the less likely that is to
1782 : : * be needed. So we can hope this is okay. Perhaps someday we'll decide
1783 : : * we need to partition the hash table to limit the time spent holding any
1784 : : * one lock.
1785 : : */
1786 : 136 : LWLockAcquire(&pgss->lock.lock, LW_SHARED);
1787 : :
1788 [ + - ]: 136 : if (showtext)
1789 : : {
1790 : : /*
1791 : : * Here it is safe to examine extent and gc_count without taking the
1792 : : * mutex. Note that although other processes might change
1793 : : * pgss->extent just after we look at it, the strings they then write
1794 : : * into the file cannot yet be referenced in the hashtable, so we
1795 : : * don't care whether we see them or not.
1796 : : *
1797 : : * If qtext_load_file fails, we just press on; we'll return NULL for
1798 : : * every query text.
1799 : : */
1800 [ + - ]: 136 : if (qbuffer == NULL ||
1801 [ + - ]: 136 : pgss->extent != extent ||
1802 [ - + ]: 136 : pgss->gc_count != gc_count)
1803 : : {
1804 [ # # ]: 0 : if (qbuffer)
1805 : 0 : pfree(qbuffer);
1806 : 0 : qbuffer = qtext_load_file(&qbuffer_size);
1807 : : }
1808 : : }
1809 : :
1810 : 136 : hash_seq_init(&hash_seq, pgss_hash);
1811 [ + + ]: 29725 : while ((entry = hash_seq_search(&hash_seq)) != NULL)
1812 : : {
1813 : : Datum values[PG_STAT_STATEMENTS_COLS];
1814 : : bool nulls[PG_STAT_STATEMENTS_COLS];
1815 : 29589 : int i = 0;
1816 : : Counters tmp;
1817 : : double stddev;
1818 : 29589 : int64 queryid = entry->key.queryid;
1819 : : TimestampTz stats_since;
1820 : : TimestampTz minmax_stats_since;
1821 : :
1822 : 29589 : memset(values, 0, sizeof(values));
1823 : 29589 : memset(nulls, 0, sizeof(nulls));
1824 : :
1825 : 29589 : values[i++] = ObjectIdGetDatum(entry->key.userid);
1826 : 29589 : values[i++] = ObjectIdGetDatum(entry->key.dbid);
1827 [ + + ]: 29589 : if (api_version >= PGSS_V1_9)
1828 : 29577 : values[i++] = BoolGetDatum(entry->key.toplevel);
1829 : :
1830 [ + + + + ]: 29589 : if (is_allowed_role || entry->key.userid == userid)
1831 : : {
1832 [ + - ]: 29585 : if (api_version >= PGSS_V1_2)
1833 : 29585 : values[i++] = Int64GetDatumFast(queryid);
1834 : :
1835 [ + - ]: 29585 : if (showtext)
1836 : : {
1837 : 29585 : char *qstr = qtext_fetch(entry->query_offset,
1838 : : entry->query_len,
1839 : : qbuffer,
1840 : : qbuffer_size);
1841 : :
1842 [ + - ]: 29585 : if (qstr)
1843 : : {
1844 : : char *enc;
1845 : :
1846 : 29585 : enc = pg_any_to_server(qstr,
1847 : : entry->query_len,
1848 : : entry->encoding);
1849 : :
1850 : 29585 : values[i++] = CStringGetTextDatum(enc);
1851 : :
1852 [ - + ]: 29585 : if (enc != qstr)
1853 : 0 : pfree(enc);
1854 : : }
1855 : : else
1856 : : {
1857 : : /* Just return a null if we fail to find the text */
1858 : 0 : nulls[i++] = true;
1859 : : }
1860 : : }
1861 : : else
1862 : : {
1863 : : /* Query text not requested */
1864 : 0 : nulls[i++] = true;
1865 : : }
1866 : : }
1867 : : else
1868 : : {
1869 : : /* Don't show queryid */
1870 [ + - ]: 4 : if (api_version >= PGSS_V1_2)
1871 : 4 : nulls[i++] = true;
1872 : :
1873 : : /*
1874 : : * Don't show query text, but hint as to the reason for not doing
1875 : : * so if it was requested
1876 : : */
1877 [ + - ]: 4 : if (showtext)
1878 : 4 : values[i++] = CStringGetTextDatum("<insufficient privilege>");
1879 : : else
1880 : 0 : nulls[i++] = true;
1881 : : }
1882 : :
1883 : : /* copy counters to a local variable to keep locking time short */
1884 : 29589 : SpinLockAcquire(&entry->mutex);
1885 : 29589 : tmp = entry->counters;
1886 : 29589 : SpinLockRelease(&entry->mutex);
1887 : :
1888 : : /*
1889 : : * The spinlock is not required when reading these two as they are
1890 : : * always updated when holding pgss->lock exclusively.
1891 : : */
1892 : 29589 : stats_since = entry->stats_since;
1893 : 29589 : minmax_stats_since = entry->minmax_stats_since;
1894 : :
1895 : : /* Skip entry if unexecuted (ie, it's a pending "sticky" entry) */
1896 [ + + ]: 29589 : if (IS_STICKY(tmp))
1897 : 46 : continue;
1898 : :
1899 : : /* Note that we rely on PGSS_PLAN being 0 and PGSS_EXEC being 1. */
1900 [ + + ]: 88629 : for (int kind = 0; kind < PGSS_NUMKIND; kind++)
1901 : : {
1902 [ + + + + ]: 59086 : if (kind == PGSS_EXEC || api_version >= PGSS_V1_8)
1903 : : {
1904 : 59082 : values[i++] = Int64GetDatumFast(tmp.calls[kind]);
1905 : 59082 : values[i++] = Float8GetDatumFast(tmp.total_time[kind]);
1906 : : }
1907 : :
1908 [ + + - + : 59086 : if ((kind == PGSS_EXEC && api_version >= PGSS_V1_3) ||
+ + ]
1909 : : api_version >= PGSS_V1_8)
1910 : : {
1911 : 59082 : values[i++] = Float8GetDatumFast(tmp.min_time[kind]);
1912 : 59082 : values[i++] = Float8GetDatumFast(tmp.max_time[kind]);
1913 : 59082 : values[i++] = Float8GetDatumFast(tmp.mean_time[kind]);
1914 : :
1915 : : /*
1916 : : * Note we are calculating the population variance here, not
1917 : : * the sample variance, as we have data for the whole
1918 : : * population, so Bessel's correction is not used, and we
1919 : : * don't divide by tmp.calls - 1.
1920 : : */
1921 [ + + ]: 59082 : if (tmp.calls[kind] > 1)
1922 : 5494 : stddev = sqrt(tmp.sum_var_time[kind] / tmp.calls[kind]);
1923 : : else
1924 : 53588 : stddev = 0.0;
1925 : 59082 : values[i++] = Float8GetDatumFast(stddev);
1926 : : }
1927 : : }
1928 : 29543 : values[i++] = Int64GetDatumFast(tmp.rows);
1929 : 29543 : values[i++] = Int64GetDatumFast(tmp.shared_blks_hit);
1930 : 29543 : values[i++] = Int64GetDatumFast(tmp.shared_blks_read);
1931 [ + - ]: 29543 : if (api_version >= PGSS_V1_1)
1932 : 29543 : values[i++] = Int64GetDatumFast(tmp.shared_blks_dirtied);
1933 : 29543 : values[i++] = Int64GetDatumFast(tmp.shared_blks_written);
1934 : 29543 : values[i++] = Int64GetDatumFast(tmp.local_blks_hit);
1935 : 29543 : values[i++] = Int64GetDatumFast(tmp.local_blks_read);
1936 [ + - ]: 29543 : if (api_version >= PGSS_V1_1)
1937 : 29543 : values[i++] = Int64GetDatumFast(tmp.local_blks_dirtied);
1938 : 29543 : values[i++] = Int64GetDatumFast(tmp.local_blks_written);
1939 : 29543 : values[i++] = Int64GetDatumFast(tmp.temp_blks_read);
1940 : 29543 : values[i++] = Int64GetDatumFast(tmp.temp_blks_written);
1941 [ + - ]: 29543 : if (api_version >= PGSS_V1_1)
1942 : : {
1943 : 29543 : values[i++] = Float8GetDatumFast(tmp.shared_blk_read_time);
1944 : 29543 : values[i++] = Float8GetDatumFast(tmp.shared_blk_write_time);
1945 : : }
1946 [ + + ]: 29543 : if (api_version >= PGSS_V1_11)
1947 : : {
1948 : 29515 : values[i++] = Float8GetDatumFast(tmp.local_blk_read_time);
1949 : 29515 : values[i++] = Float8GetDatumFast(tmp.local_blk_write_time);
1950 : : }
1951 [ + + ]: 29543 : if (api_version >= PGSS_V1_10)
1952 : : {
1953 : 29524 : values[i++] = Float8GetDatumFast(tmp.temp_blk_read_time);
1954 : 29524 : values[i++] = Float8GetDatumFast(tmp.temp_blk_write_time);
1955 : : }
1956 [ + + ]: 29543 : if (api_version >= PGSS_V1_8)
1957 : : {
1958 : : char buf[256];
1959 : : Datum wal_bytes;
1960 : :
1961 : 29539 : values[i++] = Int64GetDatumFast(tmp.wal_records);
1962 : 29539 : values[i++] = Int64GetDatumFast(tmp.wal_fpi);
1963 : :
1964 : 29539 : snprintf(buf, sizeof buf, UINT64_FORMAT, tmp.wal_bytes);
1965 : :
1966 : : /* Convert to numeric. */
1967 : 29539 : wal_bytes = DirectFunctionCall3(numeric_in,
1968 : : CStringGetDatum(buf),
1969 : : ObjectIdGetDatum(0),
1970 : : Int32GetDatum(-1));
1971 : 29539 : values[i++] = wal_bytes;
1972 : : }
1973 [ + + ]: 29543 : if (api_version >= PGSS_V1_12)
1974 : : {
1975 : 29505 : values[i++] = Int64GetDatumFast(tmp.wal_buffers_full);
1976 : : }
1977 [ + + ]: 29543 : if (api_version >= PGSS_V1_10)
1978 : : {
1979 : 29524 : values[i++] = Int64GetDatumFast(tmp.jit_functions);
1980 : 29524 : values[i++] = Float8GetDatumFast(tmp.jit_generation_time);
1981 : 29524 : values[i++] = Int64GetDatumFast(tmp.jit_inlining_count);
1982 : 29524 : values[i++] = Float8GetDatumFast(tmp.jit_inlining_time);
1983 : 29524 : values[i++] = Int64GetDatumFast(tmp.jit_optimization_count);
1984 : 29524 : values[i++] = Float8GetDatumFast(tmp.jit_optimization_time);
1985 : 29524 : values[i++] = Int64GetDatumFast(tmp.jit_emission_count);
1986 : 29524 : values[i++] = Float8GetDatumFast(tmp.jit_emission_time);
1987 : : }
1988 [ + + ]: 29543 : if (api_version >= PGSS_V1_11)
1989 : : {
1990 : 29515 : values[i++] = Int64GetDatumFast(tmp.jit_deform_count);
1991 : 29515 : values[i++] = Float8GetDatumFast(tmp.jit_deform_time);
1992 : : }
1993 [ + + ]: 29543 : if (api_version >= PGSS_V1_12)
1994 : : {
1995 : 29505 : values[i++] = Int64GetDatumFast(tmp.parallel_workers_to_launch);
1996 : 29505 : values[i++] = Int64GetDatumFast(tmp.parallel_workers_launched);
1997 : : }
1998 [ + + ]: 29543 : if (api_version >= PGSS_V1_13)
1999 : : {
2000 : 29500 : values[i++] = Int64GetDatumFast(tmp.generic_plan_calls);
2001 : 29500 : values[i++] = Int64GetDatumFast(tmp.custom_plan_calls);
2002 : : }
2003 [ + + ]: 29543 : if (api_version >= PGSS_V1_11)
2004 : : {
2005 : 29515 : values[i++] = TimestampTzGetDatum(stats_since);
2006 : 29515 : values[i++] = TimestampTzGetDatum(minmax_stats_since);
2007 : : }
2008 : :
2009 : : Assert(i == (api_version == PGSS_V1_0 ? PG_STAT_STATEMENTS_COLS_V1_0 :
2010 : : api_version == PGSS_V1_1 ? PG_STAT_STATEMENTS_COLS_V1_1 :
2011 : : api_version == PGSS_V1_2 ? PG_STAT_STATEMENTS_COLS_V1_2 :
2012 : : api_version == PGSS_V1_3 ? PG_STAT_STATEMENTS_COLS_V1_3 :
2013 : : api_version == PGSS_V1_8 ? PG_STAT_STATEMENTS_COLS_V1_8 :
2014 : : api_version == PGSS_V1_9 ? PG_STAT_STATEMENTS_COLS_V1_9 :
2015 : : api_version == PGSS_V1_10 ? PG_STAT_STATEMENTS_COLS_V1_10 :
2016 : : api_version == PGSS_V1_11 ? PG_STAT_STATEMENTS_COLS_V1_11 :
2017 : : api_version == PGSS_V1_12 ? PG_STAT_STATEMENTS_COLS_V1_12 :
2018 : : api_version == PGSS_V1_13 ? PG_STAT_STATEMENTS_COLS_V1_13 :
2019 : : -1 /* fail if you forget to update this assert */ ));
2020 : :
2021 : 29543 : tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
2022 : : }
2023 : :
2024 : 136 : LWLockRelease(&pgss->lock.lock);
2025 : :
2026 [ + - ]: 136 : if (qbuffer)
2027 : 136 : pfree(qbuffer);
2028 : 136 : }
2029 : :
2030 : : /* Number of output arguments (columns) for pg_stat_statements_info */
2031 : : #define PG_STAT_STATEMENTS_INFO_COLS 2
2032 : :
2033 : : /*
2034 : : * Return statistics of pg_stat_statements.
2035 : : */
2036 : : Datum
2037 : 4 : pg_stat_statements_info(PG_FUNCTION_ARGS)
2038 : : {
2039 : : pgssGlobalStats stats;
2040 : : TupleDesc tupdesc;
2041 : 4 : Datum values[PG_STAT_STATEMENTS_INFO_COLS] = {0};
2042 : 4 : bool nulls[PG_STAT_STATEMENTS_INFO_COLS] = {0};
2043 : :
2044 [ + - - + ]: 4 : if (!pgss || !pgss_hash)
2045 [ # # ]: 0 : ereport(ERROR,
2046 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
2047 : : errmsg("pg_stat_statements must be loaded via \"shared_preload_libraries\"")));
2048 : :
2049 : : /* Build a tuple descriptor for our result type */
2050 [ - + ]: 4 : if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
2051 [ # # ]: 0 : elog(ERROR, "return type must be a row type");
2052 : :
2053 : : /* Read global statistics for pg_stat_statements */
2054 : 4 : SpinLockAcquire(&pgss->mutex);
2055 : 4 : stats = pgss->stats;
2056 : 4 : SpinLockRelease(&pgss->mutex);
2057 : :
2058 : 4 : values[0] = Int64GetDatum(stats.dealloc);
2059 : 4 : values[1] = TimestampTzGetDatum(stats.stats_reset);
2060 : :
2061 : 4 : PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls)));
2062 : : }
2063 : :
2064 : : /*
2065 : : * Allocate a new hashtable entry.
2066 : : * caller must hold an exclusive lock on pgss->lock
2067 : : *
2068 : : * "query" need not be null-terminated; we rely on query_len instead
2069 : : *
2070 : : * If "sticky" is true, make the new entry artificially sticky so that it will
2071 : : * probably still be there when the query finishes execution. We do this by
2072 : : * giving it a median usage value rather than the normal value. (Strictly
2073 : : * speaking, query strings are normalized on a best effort basis, though it
2074 : : * would be difficult to demonstrate this even under artificial conditions.)
2075 : : *
2076 : : * Note: despite needing exclusive lock, it's not an error for the target
2077 : : * entry to already exist. This is because pgss_store releases and
2078 : : * reacquires lock after failing to find a match; so someone else could
2079 : : * have made the entry while we waited to get exclusive lock.
2080 : : */
2081 : : static pgssEntry *
2082 : 59944 : entry_alloc(pgssHashKey *key, Size query_offset, int query_len, int encoding,
2083 : : bool sticky)
2084 : : {
2085 : : pgssEntry *entry;
2086 : : bool found;
2087 : :
2088 : : /* Make space if needed */
2089 [ - + ]: 59944 : while (hash_get_num_entries(pgss_hash) >= pgss_max)
2090 : 0 : entry_dealloc();
2091 : :
2092 : : /* Find or create an entry with desired hash code */
2093 : 59944 : entry = (pgssEntry *) hash_search(pgss_hash, key, HASH_ENTER, &found);
2094 : :
2095 [ + - ]: 59944 : if (!found)
2096 : : {
2097 : : /* New entry, initialize it */
2098 : :
2099 : : /* reset the statistics */
2100 : 59944 : memset(&entry->counters, 0, sizeof(Counters));
2101 : : /* set the appropriate initial usage count */
2102 [ + + ]: 59944 : entry->counters.usage = sticky ? pgss->cur_median_usage : USAGE_INIT;
2103 : : /* re-initialize the mutex each time ... we assume no one using it */
2104 : 59944 : SpinLockInit(&entry->mutex);
2105 : : /* ... and don't forget the query text metadata */
2106 : : Assert(query_len >= 0);
2107 : 59944 : entry->query_offset = query_offset;
2108 : 59944 : entry->query_len = query_len;
2109 : 59944 : entry->encoding = encoding;
2110 : 59944 : entry->stats_since = GetCurrentTimestamp();
2111 : 59944 : entry->minmax_stats_since = entry->stats_since;
2112 : : }
2113 : :
2114 : 59944 : return entry;
2115 : : }
2116 : :
2117 : : /*
2118 : : * qsort comparator for sorting into increasing usage order
2119 : : */
2120 : : static int
2121 : 0 : entry_cmp(const void *lhs, const void *rhs)
2122 : : {
2123 : 0 : double l_usage = (*(pgssEntry *const *) lhs)->counters.usage;
2124 : 0 : double r_usage = (*(pgssEntry *const *) rhs)->counters.usage;
2125 : :
2126 [ # # ]: 0 : if (l_usage < r_usage)
2127 : 0 : return -1;
2128 [ # # ]: 0 : else if (l_usage > r_usage)
2129 : 0 : return +1;
2130 : : else
2131 : 0 : return 0;
2132 : : }
2133 : :
2134 : : /*
2135 : : * Deallocate least-used entries.
2136 : : *
2137 : : * Caller must hold an exclusive lock on pgss->lock.
2138 : : */
2139 : : static void
2140 : 0 : entry_dealloc(void)
2141 : : {
2142 : : HASH_SEQ_STATUS hash_seq;
2143 : : pgssEntry **entries;
2144 : : pgssEntry *entry;
2145 : : int nvictims;
2146 : : int i;
2147 : : Size tottextlen;
2148 : : int nvalidtexts;
2149 : :
2150 : : /*
2151 : : * Sort entries by usage and deallocate USAGE_DEALLOC_PERCENT of them.
2152 : : * While we're scanning the table, apply the decay factor to the usage
2153 : : * values, and update the mean query length.
2154 : : *
2155 : : * Note that the mean query length is almost immediately obsolete, since
2156 : : * we compute it before not after discarding the least-used entries.
2157 : : * Hopefully, that doesn't affect the mean too much; it doesn't seem worth
2158 : : * making two passes to get a more current result. Likewise, the new
2159 : : * cur_median_usage includes the entries we're about to zap.
2160 : : */
2161 : :
2162 : 0 : entries = palloc(hash_get_num_entries(pgss_hash) * sizeof(pgssEntry *));
2163 : :
2164 : 0 : i = 0;
2165 : 0 : tottextlen = 0;
2166 : 0 : nvalidtexts = 0;
2167 : :
2168 : 0 : hash_seq_init(&hash_seq, pgss_hash);
2169 [ # # ]: 0 : while ((entry = hash_seq_search(&hash_seq)) != NULL)
2170 : : {
2171 : 0 : entries[i++] = entry;
2172 : : /* "Sticky" entries get a different usage decay rate. */
2173 [ # # ]: 0 : if (IS_STICKY(entry->counters))
2174 : 0 : entry->counters.usage *= STICKY_DECREASE_FACTOR;
2175 : : else
2176 : 0 : entry->counters.usage *= USAGE_DECREASE_FACTOR;
2177 : : /* In the mean length computation, ignore dropped texts. */
2178 [ # # ]: 0 : if (entry->query_len >= 0)
2179 : : {
2180 : 0 : tottextlen += entry->query_len + 1;
2181 : 0 : nvalidtexts++;
2182 : : }
2183 : : }
2184 : :
2185 : : /* Sort into increasing order by usage */
2186 : 0 : qsort(entries, i, sizeof(pgssEntry *), entry_cmp);
2187 : :
2188 : : /* Record the (approximate) median usage */
2189 [ # # ]: 0 : if (i > 0)
2190 : 0 : pgss->cur_median_usage = entries[i / 2]->counters.usage;
2191 : : /* Record the mean query length */
2192 [ # # ]: 0 : if (nvalidtexts > 0)
2193 : 0 : pgss->mean_query_len = tottextlen / nvalidtexts;
2194 : : else
2195 : 0 : pgss->mean_query_len = ASSUMED_LENGTH_INIT;
2196 : :
2197 : : /* Now zap an appropriate fraction of lowest-usage entries */
2198 [ # # ]: 0 : nvictims = Max(10, i * USAGE_DEALLOC_PERCENT / 100);
2199 : 0 : nvictims = Min(nvictims, i);
2200 : :
2201 [ # # ]: 0 : for (i = 0; i < nvictims; i++)
2202 : : {
2203 : 0 : hash_search(pgss_hash, &entries[i]->key, HASH_REMOVE, NULL);
2204 : : }
2205 : :
2206 : 0 : pfree(entries);
2207 : :
2208 : : /* Increment the number of times entries are deallocated */
2209 : 0 : SpinLockAcquire(&pgss->mutex);
2210 : 0 : pgss->stats.dealloc += 1;
2211 : 0 : SpinLockRelease(&pgss->mutex);
2212 : 0 : }
2213 : :
2214 : : /*
2215 : : * Given a query string (not necessarily null-terminated), allocate a new
2216 : : * entry in the external query text file and store the string there.
2217 : : *
2218 : : * If successful, returns true, and stores the new entry's offset in the file
2219 : : * into *query_offset. Also, if gc_count isn't NULL, *gc_count is set to the
2220 : : * number of garbage collections that have occurred so far.
2221 : : *
2222 : : * On failure, returns false.
2223 : : *
2224 : : * At least a shared lock on pgss->lock must be held by the caller, so as
2225 : : * to prevent a concurrent garbage collection. Share-lock-holding callers
2226 : : * should pass a gc_count pointer to obtain the number of garbage collections,
2227 : : * so that they can recheck the count after obtaining exclusive lock to
2228 : : * detect whether a garbage collection occurred (and removed this entry).
2229 : : */
2230 : : static bool
2231 : 31377 : qtext_store(const char *query, int query_len,
2232 : : Size *query_offset, int *gc_count)
2233 : : {
2234 : : Size off;
2235 : : int fd;
2236 : :
2237 : : /*
2238 : : * We use a spinlock to protect extent/n_writers/gc_count, so that
2239 : : * multiple processes may execute this function concurrently.
2240 : : */
2241 : 31377 : SpinLockAcquire(&pgss->mutex);
2242 : 31377 : off = pgss->extent;
2243 : 31377 : pgss->extent += query_len + 1;
2244 : 31377 : pgss->n_writers++;
2245 [ + - ]: 31377 : if (gc_count)
2246 : 31377 : *gc_count = pgss->gc_count;
2247 : 31377 : SpinLockRelease(&pgss->mutex);
2248 : :
2249 : 31377 : *query_offset = off;
2250 : :
2251 : : /*
2252 : : * Don't allow the file to grow larger than what qtext_load_file can
2253 : : * (theoretically) handle. This has been seen to be reachable on 32-bit
2254 : : * platforms.
2255 : : */
2256 [ - + ]: 31377 : if (unlikely(query_len >= MaxAllocHugeSize - off))
2257 : : {
2258 : 0 : errno = EFBIG; /* not quite right, but it'll do */
2259 : 0 : fd = -1;
2260 : 0 : goto error;
2261 : : }
2262 : :
2263 : : /* Now write the data into the successfully-reserved part of the file */
2264 : 31377 : fd = OpenTransientFile(PGSS_TEXT_FILE, O_RDWR | O_CREAT | PG_BINARY);
2265 [ - + ]: 31377 : if (fd < 0)
2266 : 0 : goto error;
2267 : :
2268 [ - + ]: 31377 : if (pg_pwrite(fd, query, query_len, off) != query_len)
2269 : 0 : goto error;
2270 [ - + ]: 31377 : if (pg_pwrite(fd, "\0", 1, off + query_len) != 1)
2271 : 0 : goto error;
2272 : :
2273 : 31377 : CloseTransientFile(fd);
2274 : :
2275 : : /* Mark our write complete */
2276 : 31377 : SpinLockAcquire(&pgss->mutex);
2277 : 31377 : pgss->n_writers--;
2278 : 31377 : SpinLockRelease(&pgss->mutex);
2279 : :
2280 : 31377 : return true;
2281 : :
2282 : 0 : error:
2283 [ # # ]: 0 : ereport(LOG,
2284 : : (errcode_for_file_access(),
2285 : : errmsg("could not write file \"%s\": %m",
2286 : : PGSS_TEXT_FILE)));
2287 : :
2288 [ # # ]: 0 : if (fd >= 0)
2289 : 0 : CloseTransientFile(fd);
2290 : :
2291 : : /* Mark our write complete */
2292 : 0 : SpinLockAcquire(&pgss->mutex);
2293 : 0 : pgss->n_writers--;
2294 : 0 : SpinLockRelease(&pgss->mutex);
2295 : :
2296 : 0 : return false;
2297 : : }
2298 : :
2299 : : /*
2300 : : * Read the external query text file into a palloc'd buffer.
2301 : : *
2302 : : * Returns NULL (without throwing an error) if unable to read, eg
2303 : : * file not there or insufficient memory.
2304 : : *
2305 : : * On success, the buffer size is also returned into *buffer_size.
2306 : : *
2307 : : * This can be called without any lock on pgss->lock, but in that case
2308 : : * the caller is responsible for verifying that the result is sane.
2309 : : */
2310 : : static char *
2311 : 143 : qtext_load_file(Size *buffer_size)
2312 : : {
2313 : : char *buf;
2314 : : int fd;
2315 : : struct stat stat;
2316 : : Size nread;
2317 : :
2318 : 143 : fd = OpenTransientFile(PGSS_TEXT_FILE, O_RDONLY | PG_BINARY);
2319 [ - + ]: 143 : if (fd < 0)
2320 : : {
2321 [ # # ]: 0 : if (errno != ENOENT)
2322 [ # # ]: 0 : ereport(LOG,
2323 : : (errcode_for_file_access(),
2324 : : errmsg("could not read file \"%s\": %m",
2325 : : PGSS_TEXT_FILE)));
2326 : 0 : return NULL;
2327 : : }
2328 : :
2329 : : /* Get file length */
2330 [ - + ]: 143 : if (fstat(fd, &stat))
2331 : : {
2332 [ # # ]: 0 : ereport(LOG,
2333 : : (errcode_for_file_access(),
2334 : : errmsg("could not stat file \"%s\": %m",
2335 : : PGSS_TEXT_FILE)));
2336 : 0 : CloseTransientFile(fd);
2337 : 0 : return NULL;
2338 : : }
2339 : :
2340 : : /* Allocate buffer; beware that off_t might be wider than size_t */
2341 [ + - ]: 143 : if (stat.st_size <= MaxAllocHugeSize)
2342 : 143 : buf = (char *) palloc_extended(stat.st_size, MCXT_ALLOC_HUGE | MCXT_ALLOC_NO_OOM);
2343 : : else
2344 : 0 : buf = NULL;
2345 [ - + ]: 143 : if (buf == NULL)
2346 : : {
2347 [ # # ]: 0 : ereport(LOG,
2348 : : (errcode(ERRCODE_OUT_OF_MEMORY),
2349 : : errmsg("out of memory"),
2350 : : errdetail("Could not allocate enough memory to read file \"%s\".",
2351 : : PGSS_TEXT_FILE)));
2352 : 0 : CloseTransientFile(fd);
2353 : 0 : return NULL;
2354 : : }
2355 : :
2356 : : /*
2357 : : * OK, slurp in the file. Windows fails if we try to read more than
2358 : : * INT_MAX bytes at once, and other platforms might not like that either,
2359 : : * so read a very large file in 1GB segments.
2360 : : */
2361 : 143 : nread = 0;
2362 [ + + ]: 285 : while (nread < stat.st_size)
2363 : : {
2364 : 142 : int toread = Min(1024 * 1024 * 1024, stat.st_size - nread);
2365 : :
2366 : : /*
2367 : : * If we get a short read and errno doesn't get set, the reason is
2368 : : * probably that garbage collection truncated the file since we did
2369 : : * the fstat(), so we don't log a complaint --- but we don't return
2370 : : * the data, either, since it's most likely corrupt due to concurrent
2371 : : * writes from garbage collection.
2372 : : */
2373 : 142 : errno = 0;
2374 [ - + ]: 142 : if (read(fd, buf + nread, toread) != toread)
2375 : : {
2376 [ # # ]: 0 : if (errno)
2377 [ # # ]: 0 : ereport(LOG,
2378 : : (errcode_for_file_access(),
2379 : : errmsg("could not read file \"%s\": %m",
2380 : : PGSS_TEXT_FILE)));
2381 : 0 : pfree(buf);
2382 : 0 : CloseTransientFile(fd);
2383 : 0 : return NULL;
2384 : : }
2385 : 142 : nread += toread;
2386 : : }
2387 : :
2388 [ - + ]: 143 : if (CloseTransientFile(fd) != 0)
2389 [ # # ]: 0 : ereport(LOG,
2390 : : (errcode_for_file_access(),
2391 : : errmsg("could not close file \"%s\": %m", PGSS_TEXT_FILE)));
2392 : :
2393 : 143 : *buffer_size = nread;
2394 : 143 : return buf;
2395 : : }
2396 : :
2397 : : /*
2398 : : * Locate a query text in the file image previously read by qtext_load_file().
2399 : : *
2400 : : * We validate the given offset/length, and return NULL if bogus. Otherwise,
2401 : : * the result points to a null-terminated string within the buffer.
2402 : : */
2403 : : static char *
2404 : 88600 : qtext_fetch(Size query_offset, int query_len,
2405 : : char *buffer, Size buffer_size)
2406 : : {
2407 : : /* File read failed? */
2408 [ - + ]: 88600 : if (buffer == NULL)
2409 : 0 : return NULL;
2410 : : /* Bogus offset/length? */
2411 [ + - ]: 88600 : if (query_len < 0 ||
2412 [ - + ]: 88600 : query_offset + query_len >= buffer_size)
2413 : 0 : return NULL;
2414 : : /* As a further sanity check, make sure there's a trailing null */
2415 [ - + ]: 88600 : if (buffer[query_offset + query_len] != '\0')
2416 : 0 : return NULL;
2417 : : /* Looks OK */
2418 : 88600 : return buffer + query_offset;
2419 : : }
2420 : :
2421 : : /*
2422 : : * Do we need to garbage-collect the external query text file?
2423 : : *
2424 : : * Caller should hold at least a shared lock on pgss->lock.
2425 : : */
2426 : : static bool
2427 : 31377 : need_gc_qtexts(void)
2428 : : {
2429 : : Size extent;
2430 : :
2431 : : /* Read shared extent pointer */
2432 : 31377 : SpinLockAcquire(&pgss->mutex);
2433 : 31377 : extent = pgss->extent;
2434 : 31377 : SpinLockRelease(&pgss->mutex);
2435 : :
2436 : : /*
2437 : : * Don't proceed if file does not exceed 512 bytes per possible entry.
2438 : : *
2439 : : * Here and in the next test, 32-bit machines have overflow hazards if
2440 : : * pgss_max and/or mean_query_len are large. Force the multiplications
2441 : : * and comparisons to be done in uint64 arithmetic to forestall trouble.
2442 : : */
2443 [ + - ]: 31377 : if ((uint64) extent < (uint64) 512 * pgss_max)
2444 : 31377 : return false;
2445 : :
2446 : : /*
2447 : : * Don't proceed if file is less than about 50% bloat. Nothing can or
2448 : : * should be done in the event of unusually large query texts accounting
2449 : : * for file's large size. We go to the trouble of maintaining the mean
2450 : : * query length in order to prevent garbage collection from thrashing
2451 : : * uselessly.
2452 : : */
2453 [ # # ]: 0 : if ((uint64) extent < (uint64) pgss->mean_query_len * pgss_max * 2)
2454 : 0 : return false;
2455 : :
2456 : 0 : return true;
2457 : : }
2458 : :
2459 : : /*
2460 : : * Garbage-collect orphaned query texts in external file.
2461 : : *
2462 : : * This won't be called often in the typical case, since it's likely that
2463 : : * there won't be too much churn, and besides, a similar compaction process
2464 : : * occurs when serializing to disk at shutdown or as part of resetting.
2465 : : * Despite this, it seems prudent to plan for the edge case where the file
2466 : : * becomes unreasonably large, with no other method of compaction likely to
2467 : : * occur in the foreseeable future.
2468 : : *
2469 : : * The caller must hold an exclusive lock on pgss->lock.
2470 : : *
2471 : : * At the first sign of trouble we unlink the query text file to get a clean
2472 : : * slate (although existing statistics are retained), rather than risk
2473 : : * thrashing by allowing the same problem case to recur indefinitely.
2474 : : */
2475 : : static void
2476 : 0 : gc_qtexts(void)
2477 : : {
2478 : : char *qbuffer;
2479 : : Size qbuffer_size;
2480 : 0 : FILE *qfile = NULL;
2481 : : HASH_SEQ_STATUS hash_seq;
2482 : : pgssEntry *entry;
2483 : : Size extent;
2484 : : int nentries;
2485 : :
2486 : : /*
2487 : : * When called from pgss_store, some other session might have proceeded
2488 : : * with garbage collection in the no-lock-held interim of lock strength
2489 : : * escalation. Check once more that this is actually necessary.
2490 : : */
2491 [ # # ]: 0 : if (!need_gc_qtexts())
2492 : 0 : return;
2493 : :
2494 : : /*
2495 : : * Load the old texts file. If we fail (out of memory, for instance),
2496 : : * invalidate query texts. Hopefully this is rare. It might seem better
2497 : : * to leave things alone on an OOM failure, but the problem is that the
2498 : : * file is only going to get bigger; hoping for a future non-OOM result is
2499 : : * risky and can easily lead to complete denial of service.
2500 : : */
2501 : 0 : qbuffer = qtext_load_file(&qbuffer_size);
2502 [ # # ]: 0 : if (qbuffer == NULL)
2503 : 0 : goto gc_fail;
2504 : :
2505 : : /*
2506 : : * We overwrite the query texts file in place, so as to reduce the risk of
2507 : : * an out-of-disk-space failure. Since the file is guaranteed not to get
2508 : : * larger, this should always work on traditional filesystems; though we
2509 : : * could still lose on copy-on-write filesystems.
2510 : : */
2511 : 0 : qfile = AllocateFile(PGSS_TEXT_FILE, PG_BINARY_W);
2512 [ # # ]: 0 : if (qfile == NULL)
2513 : : {
2514 [ # # ]: 0 : ereport(LOG,
2515 : : (errcode_for_file_access(),
2516 : : errmsg("could not write file \"%s\": %m",
2517 : : PGSS_TEXT_FILE)));
2518 : 0 : goto gc_fail;
2519 : : }
2520 : :
2521 : 0 : extent = 0;
2522 : 0 : nentries = 0;
2523 : :
2524 : 0 : hash_seq_init(&hash_seq, pgss_hash);
2525 [ # # ]: 0 : while ((entry = hash_seq_search(&hash_seq)) != NULL)
2526 : : {
2527 : 0 : int query_len = entry->query_len;
2528 : 0 : char *qry = qtext_fetch(entry->query_offset,
2529 : : query_len,
2530 : : qbuffer,
2531 : : qbuffer_size);
2532 : :
2533 [ # # ]: 0 : if (qry == NULL)
2534 : : {
2535 : : /* Trouble ... drop the text */
2536 : 0 : entry->query_offset = 0;
2537 : 0 : entry->query_len = -1;
2538 : : /* entry will not be counted in mean query length computation */
2539 : 0 : continue;
2540 : : }
2541 : :
2542 [ # # ]: 0 : if (fwrite(qry, 1, query_len + 1, qfile) != query_len + 1)
2543 : : {
2544 [ # # ]: 0 : ereport(LOG,
2545 : : (errcode_for_file_access(),
2546 : : errmsg("could not write file \"%s\": %m",
2547 : : PGSS_TEXT_FILE)));
2548 : 0 : hash_seq_term(&hash_seq);
2549 : 0 : goto gc_fail;
2550 : : }
2551 : :
2552 : 0 : entry->query_offset = extent;
2553 : 0 : extent += query_len + 1;
2554 : 0 : nentries++;
2555 : : }
2556 : :
2557 : : /*
2558 : : * Truncate away any now-unused space. If this fails for some odd reason,
2559 : : * we log it, but there's no need to fail.
2560 : : */
2561 [ # # ]: 0 : if (ftruncate(fileno(qfile), extent) != 0)
2562 [ # # ]: 0 : ereport(LOG,
2563 : : (errcode_for_file_access(),
2564 : : errmsg("could not truncate file \"%s\": %m",
2565 : : PGSS_TEXT_FILE)));
2566 : :
2567 [ # # ]: 0 : if (FreeFile(qfile))
2568 : : {
2569 [ # # ]: 0 : ereport(LOG,
2570 : : (errcode_for_file_access(),
2571 : : errmsg("could not write file \"%s\": %m",
2572 : : PGSS_TEXT_FILE)));
2573 : 0 : qfile = NULL;
2574 : 0 : goto gc_fail;
2575 : : }
2576 : :
2577 [ # # ]: 0 : elog(DEBUG1, "pgss gc of queries file shrunk size from %zu to %zu",
2578 : : pgss->extent, extent);
2579 : :
2580 : : /* Reset the shared extent pointer */
2581 : 0 : pgss->extent = extent;
2582 : :
2583 : : /*
2584 : : * Also update the mean query length, to be sure that need_gc_qtexts()
2585 : : * won't still think we have a problem.
2586 : : */
2587 [ # # ]: 0 : if (nentries > 0)
2588 : 0 : pgss->mean_query_len = extent / nentries;
2589 : : else
2590 : 0 : pgss->mean_query_len = ASSUMED_LENGTH_INIT;
2591 : :
2592 : 0 : pfree(qbuffer);
2593 : :
2594 : : /*
2595 : : * OK, count a garbage collection cycle. (Note: even though we have
2596 : : * exclusive lock on pgss->lock, we must take pgss->mutex for this, since
2597 : : * other processes may examine gc_count while holding only the mutex.
2598 : : * Also, we have to advance the count *after* we've rewritten the file,
2599 : : * else other processes might not realize they read a stale file.)
2600 : : */
2601 : 0 : record_gc_qtexts();
2602 : :
2603 : 0 : return;
2604 : :
2605 : 0 : gc_fail:
2606 : : /* clean up resources */
2607 [ # # ]: 0 : if (qfile)
2608 : 0 : FreeFile(qfile);
2609 [ # # ]: 0 : if (qbuffer)
2610 : 0 : pfree(qbuffer);
2611 : :
2612 : : /*
2613 : : * Since the contents of the external file are now uncertain, mark all
2614 : : * hashtable entries as having invalid texts.
2615 : : */
2616 : 0 : hash_seq_init(&hash_seq, pgss_hash);
2617 [ # # ]: 0 : while ((entry = hash_seq_search(&hash_seq)) != NULL)
2618 : : {
2619 : 0 : entry->query_offset = 0;
2620 : 0 : entry->query_len = -1;
2621 : : }
2622 : :
2623 : : /*
2624 : : * Destroy the query text file and create a new, empty one
2625 : : */
2626 : 0 : (void) unlink(PGSS_TEXT_FILE);
2627 : 0 : qfile = AllocateFile(PGSS_TEXT_FILE, PG_BINARY_W);
2628 [ # # ]: 0 : if (qfile == NULL)
2629 [ # # ]: 0 : ereport(LOG,
2630 : : (errcode_for_file_access(),
2631 : : errmsg("could not recreate file \"%s\": %m",
2632 : : PGSS_TEXT_FILE)));
2633 : : else
2634 : 0 : FreeFile(qfile);
2635 : :
2636 : : /* Reset the shared extent pointer */
2637 : 0 : pgss->extent = 0;
2638 : :
2639 : : /* Reset mean_query_len to match the new state */
2640 : 0 : pgss->mean_query_len = ASSUMED_LENGTH_INIT;
2641 : :
2642 : : /*
2643 : : * Bump the GC count even though we failed.
2644 : : *
2645 : : * This is needed to make concurrent readers of file without any lock on
2646 : : * pgss->lock notice existence of new version of file. Once readers
2647 : : * subsequently observe a change in GC count with pgss->lock held, that
2648 : : * forces a safe reopen of file. Writers also require that we bump here,
2649 : : * of course. (As required by locking protocol, readers and writers don't
2650 : : * trust earlier file contents until gc_count is found unchanged after
2651 : : * pgss->lock acquired in shared or exclusive mode respectively.)
2652 : : */
2653 : 0 : record_gc_qtexts();
2654 : : }
2655 : :
2656 : : #define SINGLE_ENTRY_RESET(e) \
2657 : : if (e) { \
2658 : : if (minmax_only) { \
2659 : : /* When requested reset only min/max statistics of an entry */ \
2660 : : for (int kind = 0; kind < PGSS_NUMKIND; kind++) \
2661 : : { \
2662 : : e->counters.max_time[kind] = 0; \
2663 : : e->counters.min_time[kind] = 0; \
2664 : : } \
2665 : : e->minmax_stats_since = stats_reset; \
2666 : : } \
2667 : : else \
2668 : : { \
2669 : : /* Remove the key otherwise */ \
2670 : : hash_search(pgss_hash, &e->key, HASH_REMOVE, NULL); \
2671 : : num_remove++; \
2672 : : } \
2673 : : }
2674 : :
2675 : : /*
2676 : : * Reset entries corresponding to parameters passed.
2677 : : */
2678 : : static TimestampTz
2679 : 122 : entry_reset(Oid userid, Oid dbid, int64 queryid, bool minmax_only)
2680 : : {
2681 : : HASH_SEQ_STATUS hash_seq;
2682 : : pgssEntry *entry;
2683 : : FILE *qfile;
2684 : : int64 num_entries;
2685 : 122 : int64 num_remove = 0;
2686 : : pgssHashKey key;
2687 : : TimestampTz stats_reset;
2688 : :
2689 [ + - - + ]: 122 : if (!pgss || !pgss_hash)
2690 [ # # ]: 0 : ereport(ERROR,
2691 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
2692 : : errmsg("pg_stat_statements must be loaded via \"shared_preload_libraries\"")));
2693 : :
2694 : 122 : LWLockAcquire(&pgss->lock.lock, LW_EXCLUSIVE);
2695 : 122 : num_entries = hash_get_num_entries(pgss_hash);
2696 : :
2697 : 122 : stats_reset = GetCurrentTimestamp();
2698 : :
2699 [ + + + + : 122 : if (userid != 0 && dbid != 0 && queryid != INT64CONST(0))
+ - ]
2700 : : {
2701 : : /* If all the parameters are available, use the fast path. */
2702 : 1 : memset(&key, 0, sizeof(pgssHashKey));
2703 : 1 : key.userid = userid;
2704 : 1 : key.dbid = dbid;
2705 : 1 : key.queryid = queryid;
2706 : :
2707 : : /*
2708 : : * Reset the entry if it exists, starting with the non-top-level
2709 : : * entry.
2710 : : */
2711 : 1 : key.toplevel = false;
2712 : 1 : entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
2713 : :
2714 [ - + - - : 1 : SINGLE_ENTRY_RESET(entry);
- - ]
2715 : :
2716 : : /* Also reset the top-level entry if it exists. */
2717 : 1 : key.toplevel = true;
2718 : 1 : entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
2719 : :
2720 [ + - - + : 1 : SINGLE_ENTRY_RESET(entry);
- - ]
2721 : : }
2722 [ + + + - : 121 : else if (userid != 0 || dbid != 0 || queryid != INT64CONST(0))
+ + ]
2723 : : {
2724 : : /* Reset entries corresponding to valid parameters. */
2725 : 4 : hash_seq_init(&hash_seq, pgss_hash);
2726 [ + + ]: 51 : while ((entry = hash_seq_search(&hash_seq)) != NULL)
2727 : : {
2728 [ + + + + : 47 : if ((!userid || entry->key.userid == userid) &&
- + ]
2729 [ - - + + ]: 36 : (!dbid || entry->key.dbid == dbid) &&
2730 [ + + ]: 34 : (!queryid || entry->key.queryid == queryid))
2731 : : {
2732 [ + - + + : 7 : SINGLE_ENTRY_RESET(entry);
+ + ]
2733 : : }
2734 : : }
2735 : : }
2736 : : else
2737 : : {
2738 : : /* Reset all entries. */
2739 : 117 : hash_seq_init(&hash_seq, pgss_hash);
2740 [ + + ]: 1158 : while ((entry = hash_seq_search(&hash_seq)) != NULL)
2741 : : {
2742 [ + - + + : 946 : SINGLE_ENTRY_RESET(entry);
+ + ]
2743 : : }
2744 : : }
2745 : :
2746 : : /* All entries are removed? */
2747 [ + + ]: 122 : if (num_entries != num_remove)
2748 : 6 : goto release_lock;
2749 : :
2750 : : /*
2751 : : * Reset global statistics for pg_stat_statements since all entries are
2752 : : * removed.
2753 : : */
2754 : 116 : SpinLockAcquire(&pgss->mutex);
2755 : 116 : pgss->stats.dealloc = 0;
2756 : 116 : pgss->stats.stats_reset = stats_reset;
2757 : 116 : SpinLockRelease(&pgss->mutex);
2758 : :
2759 : : /*
2760 : : * Write new empty query file, perhaps even creating a new one to recover
2761 : : * if the file was missing.
2762 : : */
2763 : 116 : qfile = AllocateFile(PGSS_TEXT_FILE, PG_BINARY_W);
2764 [ - + ]: 116 : if (qfile == NULL)
2765 : : {
2766 [ # # ]: 0 : ereport(LOG,
2767 : : (errcode_for_file_access(),
2768 : : errmsg("could not create file \"%s\": %m",
2769 : : PGSS_TEXT_FILE)));
2770 : 0 : goto done;
2771 : : }
2772 : :
2773 : : /* If ftruncate fails, log it, but it's not a fatal problem */
2774 [ - + ]: 116 : if (ftruncate(fileno(qfile), 0) != 0)
2775 [ # # ]: 0 : ereport(LOG,
2776 : : (errcode_for_file_access(),
2777 : : errmsg("could not truncate file \"%s\": %m",
2778 : : PGSS_TEXT_FILE)));
2779 : :
2780 : 116 : FreeFile(qfile);
2781 : :
2782 : 116 : done:
2783 : 116 : pgss->extent = 0;
2784 : : /* This counts as a query text garbage collection for our purposes */
2785 : 116 : record_gc_qtexts();
2786 : :
2787 : 122 : release_lock:
2788 : 122 : LWLockRelease(&pgss->lock.lock);
2789 : :
2790 : 122 : return stats_reset;
2791 : : }
2792 : :
2793 : : /*
2794 : : * Generate a normalized version of the query string that will be used to
2795 : : * represent all similar queries.
2796 : : *
2797 : : * Note that the normalized representation may well vary depending on
2798 : : * just which "equivalent" query is used to create the hashtable entry.
2799 : : * We assume this is OK.
2800 : : *
2801 : : * If query_loc > 0, then "query" has been advanced by that much compared to
2802 : : * the original string start, so we need to translate the provided locations
2803 : : * to compensate. (This lets us avoid re-scanning statements before the one
2804 : : * of interest, so it's worth doing.)
2805 : : *
2806 : : * *query_len_p contains the input string length, and is updated with
2807 : : * the result string length on exit. The resulting string might be longer
2808 : : * or shorter depending on what happens with replacement of constants.
2809 : : *
2810 : : * Returns a palloc'd string.
2811 : : */
2812 : : static char *
2813 : 11660 : generate_normalized_query(const JumbleState *jstate, const char *query,
2814 : : int query_loc, int *query_len_p)
2815 : : {
2816 : : char *norm_query;
2817 : 11660 : int query_len = *query_len_p;
2818 : : int norm_query_buflen, /* Space allowed for norm_query */
2819 : : len_to_wrt, /* Length (in bytes) to write */
2820 : 11660 : quer_loc = 0, /* Source query byte location */
2821 : 11660 : n_quer_loc = 0, /* Normalized query byte location */
2822 : 11660 : last_off = 0, /* Offset from start for previous tok */
2823 : 11660 : last_tok_len = 0; /* Length (in bytes) of that tok */
2824 : 11660 : int num_constants_replaced = 0;
2825 : 11660 : LocationLen *locs = NULL;
2826 : :
2827 : : /*
2828 : : * Determine constants' lengths (core system only gives us locations), and
2829 : : * return a sorted copy of jstate's LocationLen data with lengths filled
2830 : : * in.
2831 : : */
2832 : 11660 : locs = ComputeConstantLengths(jstate, query, query_loc);
2833 : :
2834 : : /*
2835 : : * Allow for $n symbols to be longer than the constants they replace.
2836 : : * Constants must take at least one byte in text form, while a $n symbol
2837 : : * certainly isn't more than 11 bytes, even if n reaches INT_MAX. We
2838 : : * could refine that limit based on the max value of n for the current
2839 : : * query, but it hardly seems worth any extra effort to do so.
2840 : : */
2841 : 11660 : norm_query_buflen = query_len + jstate->clocations_count * 10;
2842 : :
2843 : : /* Allocate result buffer */
2844 : 11660 : norm_query = palloc(norm_query_buflen + 1);
2845 : :
2846 [ + + ]: 46868 : for (int i = 0; i < jstate->clocations_count; i++)
2847 : : {
2848 : : int off, /* Offset from start for cur tok */
2849 : : tok_len; /* Length (in bytes) of that tok */
2850 : :
2851 : : /*
2852 : : * If we have an external param at this location, but no lists are
2853 : : * being squashed across the query, then we skip here; this will make
2854 : : * us print the characters found in the original query that represent
2855 : : * the parameter in the next iteration (or after the loop is done),
2856 : : * which is a bit odd but seems to work okay in most cases.
2857 : : */
2858 [ + + + + ]: 35208 : if (locs[i].extern_param && !jstate->has_squashed_lists)
2859 : 168 : continue;
2860 : :
2861 : 35040 : off = locs[i].location;
2862 : :
2863 : : /* Adjust recorded location if we're dealing with partial string */
2864 : 35040 : off -= query_loc;
2865 : :
2866 : 35040 : tok_len = locs[i].length;
2867 : :
2868 [ + + ]: 35040 : if (tok_len < 0)
2869 : 692 : continue; /* ignore any duplicates */
2870 : :
2871 : : /* Copy next chunk (what precedes the next constant) */
2872 : 34348 : len_to_wrt = off - last_off;
2873 : 34348 : len_to_wrt -= last_tok_len;
2874 : : Assert(len_to_wrt >= 0);
2875 : 34348 : memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt);
2876 : 34348 : n_quer_loc += len_to_wrt;
2877 : :
2878 : : /*
2879 : : * And insert a param symbol in place of the constant token; and, if
2880 : : * we have a squashable list, insert a placeholder comment starting
2881 : : * from the list's second value.
2882 : : */
2883 : 34348 : n_quer_loc += sprintf(norm_query + n_quer_loc, "$%d%s",
2884 : 34348 : num_constants_replaced + 1 + jstate->highest_extern_param_id,
2885 [ + + ]: 34348 : locs[i].squashed ? " /*, ... */" : "");
2886 : 34348 : num_constants_replaced++;
2887 : :
2888 : : /* move forward */
2889 : 34348 : quer_loc = off + tok_len;
2890 : 34348 : last_off = off;
2891 : 34348 : last_tok_len = tok_len;
2892 : : }
2893 : :
2894 : : /* Clean up, if needed */
2895 [ + - ]: 11660 : if (locs)
2896 : 11660 : pfree(locs);
2897 : :
2898 : : /*
2899 : : * We've copied up until the last ignorable constant. Copy over the
2900 : : * remaining bytes of the original query string.
2901 : : */
2902 : 11660 : len_to_wrt = query_len - quer_loc;
2903 : :
2904 : : Assert(len_to_wrt >= 0);
2905 : 11660 : memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt);
2906 : 11660 : n_quer_loc += len_to_wrt;
2907 : :
2908 : : Assert(n_quer_loc <= norm_query_buflen);
2909 : 11660 : norm_query[n_quer_loc] = '\0';
2910 : :
2911 : 11660 : *query_len_p = n_quer_loc;
2912 : 11660 : return norm_query;
2913 : : }
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