src/include/pgstat.h

   1 /* ----------
   2  *      pgstat.h
   3  *
   4  *      Definitions for the PostgreSQL statistics collector daemon.
   5  *
   6  *      Copyright (c) 2001-2008, PostgreSQL Global Development Group
   7  *
   8  *      $PostgreSQL$
   9  * ----------
  10  */
  11 #ifndef PGSTAT_H
  12 #define PGSTAT_H
  13
  14 #include "libpq/pqcomm.h"
  15 #include "portability/instr_time.h"
  16 #include "utils/hsearch.h"
  17 #include "utils/relcache.h"
  18 #include "utils/timestamp.h"
  19
  20
  21 /* Values for track_functions GUC variable --- order is significant! */
  22 typedef enum TrackFunctionsLevel
  23 {
  24         TRACK_FUNC_OFF,
  25         TRACK_FUNC_PL,
  26         TRACK_FUNC_ALL
  27 } TrackFunctionsLevel;
  28
  29 /* ----------
  30  * The types of backend -> collector messages
  31  * ----------
  32  */
  33 typedef enum StatMsgType
  34 {
  35         PGSTAT_MTYPE_DUMMY,
  36         PGSTAT_MTYPE_TABSTAT,
  37         PGSTAT_MTYPE_TABPURGE,
  38         PGSTAT_MTYPE_DROPDB,
  39         PGSTAT_MTYPE_RESETCOUNTER,
  40         PGSTAT_MTYPE_AUTOVAC_START,
  41         PGSTAT_MTYPE_VACUUM,
  42         PGSTAT_MTYPE_ANALYZE,
  43         PGSTAT_MTYPE_BGWRITER,
  44         PGSTAT_MTYPE_FUNCSTAT,
  45         PGSTAT_MTYPE_FUNCPURGE
  46 } StatMsgType;
  47
  48 /* ----------
  49  * The data type used for counters.
  50  * ----------
  51  */
  52 typedef int64 PgStat_Counter;
  53
  54 /* ----------
  55  * PgStat_TableCounts                   The actual per-table counts kept by a backend
  56  *
  57  * This struct should contain only actual event counters, because we memcmp
  58  * it against zeroes to detect whether there are any counts to transmit.
  59  * It is a component of PgStat_TableStatus (within-backend state) and
  60  * PgStat_TableEntry (the transmitted message format).
  61  *
  62  * Note: for a table, tuples_returned is the number of tuples successfully
  63  * fetched by heap_getnext, while tuples_fetched is the number of tuples
  64  * successfully fetched by heap_fetch under the control of bitmap indexscans.
  65  * For an index, tuples_returned is the number of index entries returned by
  66  * the index AM, while tuples_fetched is the number of tuples successfully
  67  * fetched by heap_fetch under the control of simple indexscans for this index.
  68  *
  69  * tuples_inserted/updated/deleted/hot_updated count attempted actions,
  70  * regardless of whether the transaction committed.  new_live_tuples and
  71  * new_dead_tuples are properly adjusted depending on commit or abort.
  72  * Note that new_live_tuples and new_dead_tuples can be negative!
  73  * ----------
  74  */
  75 typedef struct PgStat_TableCounts
  76 {
  77         PgStat_Counter t_numscans;
  78
  79         PgStat_Counter t_tuples_returned;
  80         PgStat_Counter t_tuples_fetched;
  81
  82         PgStat_Counter t_tuples_inserted;
  83         PgStat_Counter t_tuples_updated;
  84         PgStat_Counter t_tuples_deleted;
  85         PgStat_Counter t_tuples_hot_updated;
  86
  87         PgStat_Counter t_new_live_tuples;
  88         PgStat_Counter t_new_dead_tuples;
  89
  90         PgStat_Counter t_blocks_fetched;
  91         PgStat_Counter t_blocks_hit;
  92 } PgStat_TableCounts;
  93
  94
  95 /* ------------------------------------------------------------
  96  * Structures kept in backend local memory while accumulating counts
  97  * ------------------------------------------------------------
  98  */
  99
 100
 101 /* ----------
 102  * PgStat_TableStatus                   Per-table status within a backend
 103  *
 104  * Most of the event counters are nontransactional, ie, we count events
 105  * in committed and aborted transactions alike.  For these, we just count
 106  * directly in the PgStat_TableStatus.  However, new_live_tuples and
 107  * new_dead_tuples must be derived from tuple insertion and deletion counts
 108  * with awareness of whether the transaction or subtransaction committed or
 109  * aborted.  Hence, we also keep a stack of per-(sub)transaction status
 110  * records for every table modified in the current transaction.  At commit
 111  * or abort, we propagate tuples_inserted and tuples_deleted up to the
 112  * parent subtransaction level, or out to the parent PgStat_TableStatus,
 113  * as appropriate.
 114  * ----------
 115  */
 116 typedef struct PgStat_TableStatus
 117 {
 118         Oid                     t_id;                   /* table's OID */
 119         bool            t_shared;               /* is it a shared catalog? */
 120         struct PgStat_TableXactStatus *trans;           /* lowest subxact's counts */
 121         PgStat_TableCounts t_counts;    /* event counts to be sent */
 122 } PgStat_TableStatus;
 123
 124 /* ----------
 125  * PgStat_TableXactStatus               Per-table, per-subtransaction status
 126  * ----------
 127  */
 128 typedef struct PgStat_TableXactStatus
 129 {
 130         PgStat_Counter tuples_inserted;         /* tuples inserted in (sub)xact */
 131         PgStat_Counter tuples_deleted;          /* tuples deleted in (sub)xact */
 132         int                     nest_level;             /* subtransaction nest level */
 133         /* links to other structs for same relation: */
 134         struct PgStat_TableXactStatus *upper;           /* next higher subxact if any */
 135         PgStat_TableStatus *parent; /* per-table status */
 136         /* structs of same subxact level are linked here: */
 137         struct PgStat_TableXactStatus *next;            /* next of same subxact */
 138 } PgStat_TableXactStatus;
 139
 140
 141 /* ------------------------------------------------------------
 142  * Message formats follow
 143  * ------------------------------------------------------------
 144  */
 145
 146
 147 /* ----------
 148  * PgStat_MsgHdr                                The common message header
 149  * ----------
 150  */
 151 typedef struct PgStat_MsgHdr
 152 {
 153         StatMsgType m_type;
 154         int                     m_size;
 155 } PgStat_MsgHdr;
 156
 157 /* ----------
 158  * Space available in a message.  This will keep the UDP packets below 1K,
 159  * which should fit unfragmented into the MTU of the lo interface on most
 160  * platforms. Does anybody care for platforms where it doesn't?
 161  * ----------
 162  */
 163 #define PGSTAT_MSG_PAYLOAD      (1000 - sizeof(PgStat_MsgHdr))
 164
 165
 166 /* ----------
 167  * PgStat_MsgDummy                              A dummy message, ignored by the collector
 168  * ----------
 169  */
 170 typedef struct PgStat_MsgDummy
 171 {
 172         PgStat_MsgHdr m_hdr;
 173 } PgStat_MsgDummy;
 174
 175
 176 /* ----------
 177  * PgStat_TableEntry                    Per-table info in a MsgTabstat
 178  * ----------
 179  */
 180 typedef struct PgStat_TableEntry
 181 {
 182         Oid                     t_id;
 183         PgStat_TableCounts t_counts;
 184 } PgStat_TableEntry;
 185
 186 /* ----------
 187  * PgStat_MsgTabstat                    Sent by the backend to report table
 188  *                                                              and buffer access statistics.
 189  * ----------
 190  */
 191 #define PGSTAT_NUM_TABENTRIES  \
 192         ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - 3 * sizeof(int))  \
 193          / sizeof(PgStat_TableEntry))
 194
 195 typedef struct PgStat_MsgTabstat
 196 {
 197         PgStat_MsgHdr m_hdr;
 198         Oid                     m_databaseid;
 199         int                     m_nentries;
 200         int                     m_xact_commit;
 201         int                     m_xact_rollback;
 202         PgStat_TableEntry m_entry[PGSTAT_NUM_TABENTRIES];
 203 } PgStat_MsgTabstat;
 204
 205
 206 /* ----------
 207  * PgStat_MsgTabpurge                   Sent by the backend to tell the collector
 208  *                                                              about dead tables.
 209  * ----------
 210  */
 211 #define PGSTAT_NUM_TABPURGE  \
 212         ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
 213          / sizeof(Oid))
 214
 215 typedef struct PgStat_MsgTabpurge
 216 {
 217         PgStat_MsgHdr m_hdr;
 218         Oid                     m_databaseid;
 219         int                     m_nentries;
 220         Oid                     m_tableid[PGSTAT_NUM_TABPURGE];
 221 } PgStat_MsgTabpurge;
 222
 223
 224 /* ----------
 225  * PgStat_MsgDropdb                             Sent by the backend to tell the collector
 226  *                                                              about a dropped database
 227  * ----------
 228  */
 229 typedef struct PgStat_MsgDropdb
 230 {
 231         PgStat_MsgHdr m_hdr;
 232         Oid                     m_databaseid;
 233 } PgStat_MsgDropdb;
 234
 235
 236 /* ----------
 237  * PgStat_MsgResetcounter               Sent by the backend to tell the collector
 238  *                                                              to reset counters
 239  * ----------
 240  */
 241 typedef struct PgStat_MsgResetcounter
 242 {
 243         PgStat_MsgHdr m_hdr;
 244         Oid                     m_databaseid;
 245 } PgStat_MsgResetcounter;
 246
 247
 248 /* ----------
 249  * PgStat_MsgAutovacStart               Sent by the autovacuum daemon to signal
 250  *                                                              that a database is going to be processed
 251  * ----------
 252  */
 253 typedef struct PgStat_MsgAutovacStart
 254 {
 255         PgStat_MsgHdr m_hdr;
 256         Oid                     m_databaseid;
 257         TimestampTz m_start_time;
 258 } PgStat_MsgAutovacStart;
 259
 260
 261 /* ----------
 262  * PgStat_MsgVacuum                             Sent by the backend or autovacuum daemon
 263  *                                                              after VACUUM or VACUUM ANALYZE
 264  * ----------
 265  */
 266 typedef struct PgStat_MsgVacuum
 267 {
 268         PgStat_MsgHdr m_hdr;
 269         Oid                     m_databaseid;
 270         Oid                     m_tableoid;
 271         bool            m_analyze;
 272         bool            m_autovacuum;
 273         TimestampTz m_vacuumtime;
 274         PgStat_Counter m_tuples;
 275 } PgStat_MsgVacuum;
 276
 277
 278 /* ----------
 279  * PgStat_MsgAnalyze                    Sent by the backend or autovacuum daemon
 280  *                                                              after ANALYZE
 281  * ----------
 282  */
 283 typedef struct PgStat_MsgAnalyze
 284 {
 285         PgStat_MsgHdr m_hdr;
 286         Oid                     m_databaseid;
 287         Oid                     m_tableoid;
 288         bool            m_autovacuum;
 289         TimestampTz m_analyzetime;
 290         PgStat_Counter m_live_tuples;
 291         PgStat_Counter m_dead_tuples;
 292 } PgStat_MsgAnalyze;
 293
 294
 295 /* ----------
 296  * PgStat_MsgBgWriter                   Sent by the bgwriter to update statistics.
 297  * ----------
 298  */
 299 typedef struct PgStat_MsgBgWriter
 300 {
 301         PgStat_MsgHdr m_hdr;
 302
 303         PgStat_Counter m_timed_checkpoints;
 304         PgStat_Counter m_requested_checkpoints;
 305         PgStat_Counter m_buf_written_checkpoints;
 306         PgStat_Counter m_buf_written_clean;
 307         PgStat_Counter m_maxwritten_clean;
 308         PgStat_Counter m_buf_written_backend;
 309         PgStat_Counter m_buf_alloc;
 310 } PgStat_MsgBgWriter;
 311
 312
 313 /* ----------
 314  * PgStat_FunctionCounts        The actual per-function counts kept by a backend
 315  *
 316  * This struct should contain only actual event counters, because we memcmp
 317  * it against zeroes to detect whether there are any counts to transmit.
 318  *
 319  * Note that the time counters are in instr_time format here.  We convert to
 320  * microseconds in PgStat_Counter format when transmitting to the collector.
 321  * ----------
 322  */
 323 typedef struct PgStat_FunctionCounts
 324 {
 325         PgStat_Counter f_numcalls;
 326         instr_time      f_time;
 327         instr_time      f_time_self;
 328 } PgStat_FunctionCounts;
 329
 330 /* ----------
 331  * PgStat_BackendFunctionEntry  Entry in backend's per-function hash table
 332  * ----------
 333  */
 334 typedef struct PgStat_BackendFunctionEntry
 335 {
 336         Oid                     f_id;
 337         PgStat_FunctionCounts f_counts;
 338 } PgStat_BackendFunctionEntry;
 339
 340 /* ----------
 341  * PgStat_FunctionEntry                 Per-function info in a MsgFuncstat
 342  * ----------
 343  */
 344 typedef struct PgStat_FunctionEntry
 345 {
 346         Oid                     f_id;
 347         PgStat_Counter f_numcalls;
 348         PgStat_Counter f_time;          /* times in microseconds */
 349         PgStat_Counter f_time_self;
 350 } PgStat_FunctionEntry;
 351
 352 /* ----------
 353  * PgStat_MsgFuncstat                   Sent by the backend to report function
 354  *                                                              usage statistics.
 355  * ----------
 356  */
 357 #define PGSTAT_NUM_FUNCENTRIES  \
 358         ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
 359          / sizeof(PgStat_FunctionEntry))
 360
 361 typedef struct PgStat_MsgFuncstat
 362 {
 363         PgStat_MsgHdr m_hdr;
 364         Oid                     m_databaseid;
 365         int                     m_nentries;
 366         PgStat_FunctionEntry m_entry[PGSTAT_NUM_FUNCENTRIES];
 367 } PgStat_MsgFuncstat;
 368
 369 /* ----------
 370  * PgStat_MsgFuncpurge                  Sent by the backend to tell the collector
 371  *                                                              about dead functions.
 372  * ----------
 373  */
 374 #define PGSTAT_NUM_FUNCPURGE  \
 375         ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
 376          / sizeof(Oid))
 377
 378 typedef struct PgStat_MsgFuncpurge
 379 {
 380         PgStat_MsgHdr m_hdr;
 381         Oid                     m_databaseid;
 382         int                     m_nentries;
 383         Oid                     m_functionid[PGSTAT_NUM_FUNCPURGE];
 384 } PgStat_MsgFuncpurge;
 385
 386
 387 /* ----------
 388  * PgStat_Msg                                   Union over all possible messages.
 389  * ----------
 390  */
 391 typedef union PgStat_Msg
 392 {
 393         PgStat_MsgHdr msg_hdr;
 394         PgStat_MsgDummy msg_dummy;
 395         PgStat_MsgTabstat msg_tabstat;
 396         PgStat_MsgTabpurge msg_tabpurge;
 397         PgStat_MsgDropdb msg_dropdb;
 398         PgStat_MsgResetcounter msg_resetcounter;
 399         PgStat_MsgAutovacStart msg_autovacuum;
 400         PgStat_MsgVacuum msg_vacuum;
 401         PgStat_MsgAnalyze msg_analyze;
 402         PgStat_MsgBgWriter msg_bgwriter;
 403         PgStat_MsgFuncstat msg_funcstat;
 404         PgStat_MsgFuncpurge msg_funcpurge;
 405 } PgStat_Msg;
 406
 407
 408 /* ------------------------------------------------------------
 409  * Statistic collector data structures follow
 410  *
 411  * PGSTAT_FILE_FORMAT_ID should be changed whenever any of these
 412  * data structures change.
 413  * ------------------------------------------------------------
 414  */
 415
 416 #define PGSTAT_FILE_FORMAT_ID   0x01A5BC97
 417
 418 /* ----------
 419  * PgStat_StatDBEntry                   The collector's data per database
 420  * ----------
 421  */
 422 typedef struct PgStat_StatDBEntry
 423 {
 424         Oid                     databaseid;
 425         PgStat_Counter n_xact_commit;
 426         PgStat_Counter n_xact_rollback;
 427         PgStat_Counter n_blocks_fetched;
 428         PgStat_Counter n_blocks_hit;
 429         PgStat_Counter n_tuples_returned;
 430         PgStat_Counter n_tuples_fetched;
 431         PgStat_Counter n_tuples_inserted;
 432         PgStat_Counter n_tuples_updated;
 433         PgStat_Counter n_tuples_deleted;
 434         TimestampTz last_autovac_time;
 435
 436         /*
 437          * tables and functions must be last in the struct, because we don't
 438          * write the pointers out to the stats file.
 439          */
 440         HTAB       *tables;
 441         HTAB       *functions;
 442 } PgStat_StatDBEntry;
 443
 444
 445 /* ----------
 446  * PgStat_StatTabEntry                  The collector's data per table (or index)
 447  * ----------
 448  */
 449 typedef struct PgStat_StatTabEntry
 450 {
 451         Oid                     tableid;
 452
 453         PgStat_Counter numscans;
 454
 455         PgStat_Counter tuples_returned;
 456         PgStat_Counter tuples_fetched;
 457
 458         PgStat_Counter tuples_inserted;
 459         PgStat_Counter tuples_updated;
 460         PgStat_Counter tuples_deleted;
 461         PgStat_Counter tuples_hot_updated;
 462
 463         PgStat_Counter n_live_tuples;
 464         PgStat_Counter n_dead_tuples;
 465         PgStat_Counter last_anl_tuples;
 466
 467         PgStat_Counter blocks_fetched;
 468         PgStat_Counter blocks_hit;
 469
 470         TimestampTz vacuum_timestamp;           /* user initiated vacuum */
 471         TimestampTz autovac_vacuum_timestamp;           /* autovacuum initiated */
 472         TimestampTz analyze_timestamp;          /* user initiated */
 473         TimestampTz autovac_analyze_timestamp;          /* autovacuum initiated */
 474 } PgStat_StatTabEntry;
 475
 476
 477 /* ----------
 478  * PgStat_StatFuncEntry                 The collector's data per function
 479  * ----------
 480  */
 481 typedef struct PgStat_StatFuncEntry
 482 {
 483         Oid                     functionid;
 484
 485         PgStat_Counter f_numcalls;
 486
 487         PgStat_Counter f_time;          /* times in microseconds */
 488         PgStat_Counter f_time_self;
 489 } PgStat_StatFuncEntry;
 490
 491
 492 /*
 493  * Global statistics kept in the stats collector
 494  */
 495 typedef struct PgStat_GlobalStats
 496 {
 497         PgStat_Counter timed_checkpoints;
 498         PgStat_Counter requested_checkpoints;
 499         PgStat_Counter buf_written_checkpoints;
 500         PgStat_Counter buf_written_clean;
 501         PgStat_Counter maxwritten_clean;
 502         PgStat_Counter buf_written_backend;
 503         PgStat_Counter buf_alloc;
 504 } PgStat_GlobalStats;
 505
 506
 507 /* ----------
 508  * Shared-memory data structures
 509  * ----------
 510  */
 511
 512 /* ----------
 513  * PgBackendStatus
 514  *
 515  * Each live backend maintains a PgBackendStatus struct in shared memory
 516  * showing its current activity.  (The structs are allocated according to
 517  * BackendId, but that is not critical.)  Note that the collector process
 518  * has no involvement in, or even access to, these structs.
 519  * ----------
 520  */
 521 typedef struct PgBackendStatus
 522 {
 523         /*
 524          * To avoid locking overhead, we use the following protocol: a backend
 525          * increments st_changecount before modifying its entry, and again after
 526          * finishing a modification.  A would-be reader should note the value of
 527          * st_changecount, copy the entry into private memory, then check
 528          * st_changecount again.  If the value hasn't changed, and if it's even,
 529          * the copy is valid; otherwise start over.  This makes updates cheap
 530          * while reads are potentially expensive, but that's the tradeoff we want.
 531          */
 532         int                     st_changecount;
 533
 534         /* The entry is valid iff st_procpid > 0, unused if st_procpid == 0 */
 535         int                     st_procpid;
 536
 537         /* Times when current backend, transaction, and activity started */
 538         TimestampTz st_proc_start_timestamp;
 539         TimestampTz st_xact_start_timestamp;
 540         TimestampTz st_activity_start_timestamp;
 541
 542         /* Database OID, owning user's OID, connection client address */
 543         Oid                     st_databaseid;
 544         Oid                     st_userid;
 545         SockAddr        st_clientaddr;
 546
 547         /* Is backend currently waiting on an lmgr lock? */
 548         bool            st_waiting;
 549
 550         /* current command string; MUST be null-terminated */
 551         char       *st_activity;
 552 } PgBackendStatus;
 553
 554 /*
 555  * Working state needed to accumulate per-function-call timing statistics.
 556  */
 557 typedef struct PgStat_FunctionCallUsage
 558 {
 559         /* Link to function's hashtable entry (must still be there at exit!) */
 560         /* NULL means we are not tracking the current function call */
 561         PgStat_FunctionCounts *fs;
 562         /* Total time previously charged to function, as of function start */
 563         instr_time              save_f_time;
 564         /* Backend-wide total time as of function start */
 565         instr_time              save_total;
 566         /* system clock as of function start */
 567         instr_time              f_start;
 568 } PgStat_FunctionCallUsage;
 569
 570
 571 /* ----------
 572  * GUC parameters
 573  * ----------
 574  */
 575 extern bool pgstat_track_activities;
 576 extern bool pgstat_track_counts;
 577 extern int      pgstat_track_functions;
 578 extern int      pgstat_track_activity_query_size;
 579 extern char *pgstat_stat_tmpname;
 580 extern char *pgstat_stat_filename;
 581
 582 /*
 583  * BgWriter statistics counters are updated directly by bgwriter and bufmgr
 584  */
 585 extern PgStat_MsgBgWriter BgWriterStats;
 586
 587 /* ----------
 588  * Functions called from postmaster
 589  * ----------
 590  */
 591 extern Size BackendStatusShmemSize(void);
 592 extern void CreateSharedBackendStatus(void);
 593
 594 extern void pgstat_init(void);
 595 extern int      pgstat_start(void);
 596 extern void pgstat_reset_all(void);
 597 extern void allow_immediate_pgstat_restart(void);
 598
 599 #ifdef EXEC_BACKEND
 600 extern void PgstatCollectorMain(int argc, char *argv[]);
 601 #endif
 602
 603
 604 /* ----------
 605  * Functions called from backends
 606  * ----------
 607  */
 608 extern void pgstat_ping(void);
 609
 610 extern void pgstat_report_stat(bool force);
 611 extern void pgstat_vacuum_stat(void);
 612 extern void pgstat_drop_database(Oid databaseid);
 613
 614 extern void pgstat_clear_snapshot(void);
 615 extern void pgstat_reset_counters(void);
 616
 617 extern void pgstat_report_autovac(Oid dboid);
 618 extern void pgstat_report_vacuum(Oid tableoid, bool shared,
 619                                          bool analyze, PgStat_Counter tuples);
 620 extern void pgstat_report_analyze(Relation rel,
 621                                           PgStat_Counter livetuples,
 622                                           PgStat_Counter deadtuples);
 623
 624 extern void pgstat_initialize(void);
 625 extern void pgstat_bestart(void);
 626
 627 extern void pgstat_report_activity(const char *what);
 628 extern void pgstat_report_xact_timestamp(TimestampTz tstamp);
 629 extern void pgstat_report_waiting(bool waiting);
 630 extern const char *pgstat_get_backend_current_activity(int pid, bool checkUser);
 631
 632 extern void pgstat_initstats(Relation rel);
 633
 634 /* nontransactional event counts are simple enough to inline */
 635
 636 #define pgstat_count_heap_scan(rel)                                                                     \
 637         do {                                                                                                                    \
 638                 if (pgstat_track_counts && (rel)->pgstat_info != NULL)          \
 639                         (rel)->pgstat_info->t_counts.t_numscans++;                              \
 640         } while (0)
 641 #define pgstat_count_heap_getnext(rel)                                                          \
 642         do {                                                                                                                    \
 643                 if (pgstat_track_counts && (rel)->pgstat_info != NULL)          \
 644                         (rel)->pgstat_info->t_counts.t_tuples_returned++;               \
 645         } while (0)
 646 #define pgstat_count_heap_fetch(rel)                                                            \
 647         do {                                                                                                                    \
 648                 if (pgstat_track_counts && (rel)->pgstat_info != NULL)          \
 649                         (rel)->pgstat_info->t_counts.t_tuples_fetched++;                \
 650         } while (0)
 651 #define pgstat_count_index_scan(rel)                                                            \
 652         do {                                                                                                                    \
 653                 if (pgstat_track_counts && (rel)->pgstat_info != NULL)          \
 654                         (rel)->pgstat_info->t_counts.t_numscans++;                              \
 655         } while (0)
 656 #define pgstat_count_index_tuples(rel, n)                                                       \
 657         do {                                                                                                                    \
 658                 if (pgstat_track_counts && (rel)->pgstat_info != NULL)          \
 659                         (rel)->pgstat_info->t_counts.t_tuples_returned += (n);  \
 660         } while (0)
 661 #define pgstat_count_buffer_read(rel)                                                           \
 662         do {                                                                                                                    \
 663                 if (pgstat_track_counts && (rel)->pgstat_info != NULL)          \
 664                         (rel)->pgstat_info->t_counts.t_blocks_fetched++;                \
 665         } while (0)
 666 #define pgstat_count_buffer_hit(rel)                                                            \
 667         do {                                                                                                                    \
 668                 if (pgstat_track_counts && (rel)->pgstat_info != NULL)          \
 669                         (rel)->pgstat_info->t_counts.t_blocks_hit++;                    \
 670         } while (0)
 671
 672 extern void pgstat_count_heap_insert(Relation rel);
 673 extern void pgstat_count_heap_update(Relation rel, bool hot);
 674 extern void pgstat_count_heap_delete(Relation rel);
 675 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 676
 677 extern void pgstat_init_function_usage(FunctionCallInfoData *fcinfo,
 678                                                                            PgStat_FunctionCallUsage *fcu);
 679 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 680                                                                           bool finalize);
 681
 682 extern void AtEOXact_PgStat(bool isCommit);
 683 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 684
 685 extern void AtPrepare_PgStat(void);
 686 extern void PostPrepare_PgStat(void);
 687
 688 extern void pgstat_twophase_postcommit(TransactionId xid, uint16 info,
 689                                                    void *recdata, uint32 len);
 690 extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
 691                                                   void *recdata, uint32 len);
 692
 693 extern void pgstat_send_bgwriter(void);
 694
 695 /* ----------
 696  * Support functions for the SQL-callable functions to
 697  * generate the pgstat* views.
 698  * ----------
 699  */
 700 extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
 701 extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 702 extern PgBackendStatus *pgstat_fetch_stat_beentry(int beid);
 703 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 704 extern int      pgstat_fetch_stat_numbackends(void);
 705 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 706
 707 #endif   /* PGSTAT_H */