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Sourcecode: postgresql-8.4 version File versions

pgstat.h

/* ----------
 *    pgstat.h
 *
 *    Definitions for the PostgreSQL statistics collector daemon.
 *
 *    Copyright (c) 2001-2009, PostgreSQL Global Development Group
 *
 *    $PostgreSQL$
 * ----------
 */
#ifndef PGSTAT_H
#define PGSTAT_H

#include "libpq/pqcomm.h"
#include "portability/instr_time.h"
#include "utils/hsearch.h"
#include "utils/relcache.h"
#include "utils/timestamp.h"


/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
      TRACK_FUNC_OFF,
      TRACK_FUNC_PL,
      TRACK_FUNC_ALL
} TrackFunctionsLevel;

/* ----------
 * The types of backend -> collector messages
 * ----------
 */
typedef enum StatMsgType
{
      PGSTAT_MTYPE_DUMMY,
      PGSTAT_MTYPE_INQUIRY,
      PGSTAT_MTYPE_TABSTAT,
      PGSTAT_MTYPE_TABPURGE,
      PGSTAT_MTYPE_DROPDB,
      PGSTAT_MTYPE_RESETCOUNTER,
      PGSTAT_MTYPE_AUTOVAC_START,
      PGSTAT_MTYPE_VACUUM,
      PGSTAT_MTYPE_ANALYZE,
      PGSTAT_MTYPE_BGWRITER,
      PGSTAT_MTYPE_FUNCSTAT,
      PGSTAT_MTYPE_FUNCPURGE
} StatMsgType;

/* ----------
 * The data type used for counters.
 * ----------
 */
typedef int64 PgStat_Counter;

/* ----------
 * PgStat_TableCounts               The actual per-table counts kept by a backend
 *
 * This struct should contain only actual event counters, because we memcmp
 * it against zeroes to detect whether there are any counts to transmit.
 * It is a component of PgStat_TableStatus (within-backend state) and
 * PgStat_TableEntry (the transmitted message format).
 *
 * Note: for a table, tuples_returned is the number of tuples successfully
 * fetched by heap_getnext, while tuples_fetched is the number of tuples
 * successfully fetched by heap_fetch under the control of bitmap indexscans.
 * For an index, tuples_returned is the number of index entries returned by
 * the index AM, while tuples_fetched is the number of tuples successfully
 * fetched by heap_fetch under the control of simple indexscans for this index.
 *
 * tuples_inserted/updated/deleted/hot_updated count attempted actions,
 * regardless of whether the transaction committed.  new_live_tuples and
 * new_dead_tuples are properly adjusted depending on commit or abort.
 * Note that new_live_tuples and new_dead_tuples can be negative!
 * ----------
 */
typedef struct PgStat_TableCounts
{
      PgStat_Counter t_numscans;

      PgStat_Counter t_tuples_returned;
      PgStat_Counter t_tuples_fetched;

      PgStat_Counter t_tuples_inserted;
      PgStat_Counter t_tuples_updated;
      PgStat_Counter t_tuples_deleted;
      PgStat_Counter t_tuples_hot_updated;

      PgStat_Counter t_new_live_tuples;
      PgStat_Counter t_new_dead_tuples;

      PgStat_Counter t_blocks_fetched;
      PgStat_Counter t_blocks_hit;
} PgStat_TableCounts;


/* ------------------------------------------------------------
 * Structures kept in backend local memory while accumulating counts
 * ------------------------------------------------------------
 */


/* ----------
 * PgStat_TableStatus               Per-table status within a backend
 *
 * Most of the event counters are nontransactional, ie, we count events
 * in committed and aborted transactions alike.  For these, we just count
 * directly in the PgStat_TableStatus.    However, new_live_tuples and
 * new_dead_tuples must be derived from tuple insertion and deletion counts
 * with awareness of whether the transaction or subtransaction committed or
 * aborted.  Hence, we also keep a stack of per-(sub)transaction status
 * records for every table modified in the current transaction.  At commit
 * or abort, we propagate tuples_inserted and tuples_deleted up to the
 * parent subtransaction level, or out to the parent PgStat_TableStatus,
 * as appropriate.
 * ----------
 */
typedef struct PgStat_TableStatus
{
      Oid               t_id;             /* table's OID */
      bool        t_shared;         /* is it a shared catalog? */
      struct PgStat_TableXactStatus *trans;           /* lowest subxact's counts */
      PgStat_TableCounts t_counts;  /* event counts to be sent */
} PgStat_TableStatus;

/* ----------
 * PgStat_TableXactStatus           Per-table, per-subtransaction status
 * ----------
 */
typedef struct PgStat_TableXactStatus
{
      PgStat_Counter tuples_inserted;           /* tuples inserted in (sub)xact */
      PgStat_Counter tuples_deleted;            /* tuples deleted in (sub)xact */
      int               nest_level;       /* subtransaction nest level */
      /* links to other structs for same relation: */
      struct PgStat_TableXactStatus *upper;           /* next higher subxact if any */
      PgStat_TableStatus *parent; /* per-table status */
      /* structs of same subxact level are linked here: */
      struct PgStat_TableXactStatus *next;            /* next of same subxact */
} PgStat_TableXactStatus;


/* ------------------------------------------------------------
 * Message formats follow
 * ------------------------------------------------------------
 */


/* ----------
 * PgStat_MsgHdr                    The common message header
 * ----------
 */
typedef struct PgStat_MsgHdr
{
      StatMsgType m_type;
      int               m_size;
} PgStat_MsgHdr;

/* ----------
 * Space available in a message.  This will keep the UDP packets below 1K,
 * which should fit unfragmented into the MTU of the lo interface on most
 * platforms. Does anybody care for platforms where it doesn't?
 * ----------
 */
#define PGSTAT_MSG_PAYLOAD    (1000 - sizeof(PgStat_MsgHdr))


/* ----------
 * PgStat_MsgDummy                        A dummy message, ignored by the collector
 * ----------
 */
typedef struct PgStat_MsgDummy
{
      PgStat_MsgHdr m_hdr;
} PgStat_MsgDummy;


/* ----------
 * PgStat_MsgInquiry                Sent by a backend to ask the collector
 *                                              to write the stats file.
 * ----------
 */

typedef struct PgStat_MsgInquiry
{
      PgStat_MsgHdr     m_hdr;
      TimestampTz       inquiry_time;     /* minimum acceptable file timestamp */
} PgStat_MsgInquiry;


/* ----------
 * PgStat_TableEntry                Per-table info in a MsgTabstat
 * ----------
 */
typedef struct PgStat_TableEntry
{
      Oid               t_id;
      PgStat_TableCounts t_counts;
} PgStat_TableEntry;

/* ----------
 * PgStat_MsgTabstat                Sent by the backend to report table
 *                                              and buffer access statistics.
 * ----------
 */
#define PGSTAT_NUM_TABENTRIES  \
      ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - 3 * sizeof(int))  \
       / sizeof(PgStat_TableEntry))

typedef struct PgStat_MsgTabstat
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
      int               m_nentries;
      int               m_xact_commit;
      int               m_xact_rollback;
      PgStat_TableEntry m_entry[PGSTAT_NUM_TABENTRIES];
} PgStat_MsgTabstat;


/* ----------
 * PgStat_MsgTabpurge               Sent by the backend to tell the collector
 *                                              about dead tables.
 * ----------
 */
#define PGSTAT_NUM_TABPURGE  \
      ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
       / sizeof(Oid))

typedef struct PgStat_MsgTabpurge
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
      int               m_nentries;
      Oid               m_tableid[PGSTAT_NUM_TABPURGE];
} PgStat_MsgTabpurge;


/* ----------
 * PgStat_MsgDropdb                       Sent by the backend to tell the collector
 *                                              about a dropped database
 * ----------
 */
typedef struct PgStat_MsgDropdb
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
} PgStat_MsgDropdb;


/* ----------
 * PgStat_MsgResetcounter           Sent by the backend to tell the collector
 *                                              to reset counters
 * ----------
 */
typedef struct PgStat_MsgResetcounter
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
} PgStat_MsgResetcounter;


/* ----------
 * PgStat_MsgAutovacStart           Sent by the autovacuum daemon to signal
 *                                              that a database is going to be processed
 * ----------
 */
typedef struct PgStat_MsgAutovacStart
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
      TimestampTz m_start_time;
} PgStat_MsgAutovacStart;


/* ----------
 * PgStat_MsgVacuum                       Sent by the backend or autovacuum daemon
 *                                              after VACUUM or VACUUM ANALYZE
 * ----------
 */
typedef struct PgStat_MsgVacuum
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
      Oid               m_tableoid;
      bool        m_analyze;
      bool        m_autovacuum;
      bool        m_scanned_all;
      TimestampTz m_vacuumtime;
      PgStat_Counter m_tuples;
} PgStat_MsgVacuum;


/* ----------
 * PgStat_MsgAnalyze                Sent by the backend or autovacuum daemon
 *                                              after ANALYZE
 * ----------
 */
typedef struct PgStat_MsgAnalyze
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
      Oid               m_tableoid;
      bool        m_autovacuum;
      TimestampTz m_analyzetime;
      PgStat_Counter m_live_tuples;
      PgStat_Counter m_dead_tuples;
} PgStat_MsgAnalyze;


/* ----------
 * PgStat_MsgBgWriter               Sent by the bgwriter to update statistics.
 * ----------
 */
typedef struct PgStat_MsgBgWriter
{
      PgStat_MsgHdr m_hdr;

      PgStat_Counter m_timed_checkpoints;
      PgStat_Counter m_requested_checkpoints;
      PgStat_Counter m_buf_written_checkpoints;
      PgStat_Counter m_buf_written_clean;
      PgStat_Counter m_maxwritten_clean;
      PgStat_Counter m_buf_written_backend;
      PgStat_Counter m_buf_alloc;
} PgStat_MsgBgWriter;


/* ----------
 * PgStat_FunctionCounts      The actual per-function counts kept by a backend
 *
 * This struct should contain only actual event counters, because we memcmp
 * it against zeroes to detect whether there are any counts to transmit.
 *
 * Note that the time counters are in instr_time format here.  We convert to
 * microseconds in PgStat_Counter format when transmitting to the collector.
 * ----------
 */
typedef struct PgStat_FunctionCounts
{
      PgStat_Counter f_numcalls;
      instr_time  f_time;
      instr_time  f_time_self;
} PgStat_FunctionCounts;

/* ----------
 * PgStat_BackendFunctionEntry      Entry in backend's per-function hash table
 * ----------
 */
typedef struct PgStat_BackendFunctionEntry
{
      Oid               f_id;
      PgStat_FunctionCounts f_counts;
} PgStat_BackendFunctionEntry;

/* ----------
 * PgStat_FunctionEntry             Per-function info in a MsgFuncstat
 * ----------
 */
typedef struct PgStat_FunctionEntry
{
      Oid               f_id;
      PgStat_Counter f_numcalls;
      PgStat_Counter f_time;        /* times in microseconds */
      PgStat_Counter f_time_self;
} PgStat_FunctionEntry;

/* ----------
 * PgStat_MsgFuncstat               Sent by the backend to report function
 *                                              usage statistics.
 * ----------
 */
#define PGSTAT_NUM_FUNCENTRIES  \
      ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
       / sizeof(PgStat_FunctionEntry))

typedef struct PgStat_MsgFuncstat
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
      int               m_nentries;
      PgStat_FunctionEntry m_entry[PGSTAT_NUM_FUNCENTRIES];
} PgStat_MsgFuncstat;

/* ----------
 * PgStat_MsgFuncpurge              Sent by the backend to tell the collector
 *                                              about dead functions.
 * ----------
 */
#define PGSTAT_NUM_FUNCPURGE  \
      ((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
       / sizeof(Oid))

typedef struct PgStat_MsgFuncpurge
{
      PgStat_MsgHdr m_hdr;
      Oid               m_databaseid;
      int               m_nentries;
      Oid               m_functionid[PGSTAT_NUM_FUNCPURGE];
} PgStat_MsgFuncpurge;


/* ----------
 * PgStat_Msg                             Union over all possible messages.
 * ----------
 */
typedef union PgStat_Msg
{
      PgStat_MsgHdr msg_hdr;
      PgStat_MsgDummy msg_dummy;
      PgStat_MsgInquiry msg_inquiry;
      PgStat_MsgTabstat msg_tabstat;
      PgStat_MsgTabpurge msg_tabpurge;
      PgStat_MsgDropdb msg_dropdb;
      PgStat_MsgResetcounter msg_resetcounter;
      PgStat_MsgAutovacStart msg_autovacuum;
      PgStat_MsgVacuum msg_vacuum;
      PgStat_MsgAnalyze msg_analyze;
      PgStat_MsgBgWriter msg_bgwriter;
      PgStat_MsgFuncstat msg_funcstat;
      PgStat_MsgFuncpurge msg_funcpurge;
} PgStat_Msg;


/* ------------------------------------------------------------
 * Statistic collector data structures follow
 *
 * PGSTAT_FILE_FORMAT_ID should be changed whenever any of these
 * data structures change.
 * ------------------------------------------------------------
 */

#define PGSTAT_FILE_FORMAT_ID 0x01A5BC98

/* ----------
 * PgStat_StatDBEntry               The collector's data per database
 * ----------
 */
typedef struct PgStat_StatDBEntry
{
      Oid               databaseid;
      PgStat_Counter n_xact_commit;
      PgStat_Counter n_xact_rollback;
      PgStat_Counter n_blocks_fetched;
      PgStat_Counter n_blocks_hit;
      PgStat_Counter n_tuples_returned;
      PgStat_Counter n_tuples_fetched;
      PgStat_Counter n_tuples_inserted;
      PgStat_Counter n_tuples_updated;
      PgStat_Counter n_tuples_deleted;
      TimestampTz last_autovac_time;

      /*
       * tables and functions must be last in the struct, because we don't
       * write the pointers out to the stats file.
       */
      HTAB     *tables;
      HTAB     *functions;
} PgStat_StatDBEntry;


/* ----------
 * PgStat_StatTabEntry              The collector's data per table (or index)
 * ----------
 */
typedef struct PgStat_StatTabEntry
{
      Oid               tableid;

      PgStat_Counter numscans;

      PgStat_Counter tuples_returned;
      PgStat_Counter tuples_fetched;

      PgStat_Counter tuples_inserted;
      PgStat_Counter tuples_updated;
      PgStat_Counter tuples_deleted;
      PgStat_Counter tuples_hot_updated;

      PgStat_Counter n_live_tuples;
      PgStat_Counter n_dead_tuples;
      PgStat_Counter last_anl_tuples;

      PgStat_Counter blocks_fetched;
      PgStat_Counter blocks_hit;

      TimestampTz vacuum_timestamp;       /* user initiated vacuum */
      TimestampTz autovac_vacuum_timestamp;           /* autovacuum initiated */
      TimestampTz analyze_timestamp;            /* user initiated */
      TimestampTz autovac_analyze_timestamp;          /* autovacuum initiated */
} PgStat_StatTabEntry;


/* ----------
 * PgStat_StatFuncEntry             The collector's data per function
 * ----------
 */
typedef struct PgStat_StatFuncEntry
{
      Oid               functionid;

      PgStat_Counter f_numcalls;

      PgStat_Counter f_time;        /* times in microseconds */
      PgStat_Counter f_time_self;
} PgStat_StatFuncEntry;


/*
 * Global statistics kept in the stats collector
 */
typedef struct PgStat_GlobalStats
{
      TimestampTz stats_timestamp;        /* time of stats file update */
      PgStat_Counter timed_checkpoints;
      PgStat_Counter requested_checkpoints;
      PgStat_Counter buf_written_checkpoints;
      PgStat_Counter buf_written_clean;
      PgStat_Counter maxwritten_clean;
      PgStat_Counter buf_written_backend;
      PgStat_Counter buf_alloc;
} PgStat_GlobalStats;


/* ----------
 * Shared-memory data structures
 * ----------
 */

/* ----------
 * PgBackendStatus
 *
 * Each live backend maintains a PgBackendStatus struct in shared memory
 * showing its current activity.  (The structs are allocated according to
 * BackendId, but that is not critical.)  Note that the collector process
 * has no involvement in, or even access to, these structs.
 * ----------
 */
typedef struct PgBackendStatus
{
      /*
       * To avoid locking overhead, we use the following protocol: a backend
       * increments st_changecount before modifying its entry, and again after
       * finishing a modification.  A would-be reader should note the value of
       * st_changecount, copy the entry into private memory, then check
       * st_changecount again.  If the value hasn't changed, and if it's even,
       * the copy is valid; otherwise start over.  This makes updates cheap
       * while reads are potentially expensive, but that's the tradeoff we want.
       */
      int               st_changecount;

      /* The entry is valid iff st_procpid > 0, unused if st_procpid == 0 */
      int               st_procpid;

      /* Times when current backend, transaction, and activity started */
      TimestampTz st_proc_start_timestamp;
      TimestampTz st_xact_start_timestamp;
      TimestampTz st_activity_start_timestamp;

      /* Database OID, owning user's OID, connection client address */
      Oid               st_databaseid;
      Oid               st_userid;
      SockAddr    st_clientaddr;

      /* Is backend currently waiting on an lmgr lock? */
      bool        st_waiting;

      /* current command string; MUST be null-terminated */
      char     *st_activity;
} PgBackendStatus;

/*
 * Working state needed to accumulate per-function-call timing statistics.
 */
typedef struct PgStat_FunctionCallUsage
{
      /* Link to function's hashtable entry (must still be there at exit!) */
      /* NULL means we are not tracking the current function call */
      PgStat_FunctionCounts *fs;
      /* Total time previously charged to function, as of function start */
      instr_time        save_f_time;
      /* Backend-wide total time as of function start */
      instr_time        save_total;
      /* system clock as of function start */
      instr_time        f_start;
} PgStat_FunctionCallUsage;


/* ----------
 * GUC parameters
 * ----------
 */
extern bool pgstat_track_activities;
extern bool pgstat_track_counts;
extern int  pgstat_track_functions;
extern PGDLLIMPORT int  pgstat_track_activity_query_size;
extern char *pgstat_stat_tmpname;
extern char *pgstat_stat_filename;

/*
 * BgWriter statistics counters are updated directly by bgwriter and bufmgr
 */
extern PgStat_MsgBgWriter BgWriterStats;

/* ----------
 * Functions called from postmaster
 * ----------
 */
extern Size BackendStatusShmemSize(void);
extern void CreateSharedBackendStatus(void);

extern void pgstat_init(void);
extern int  pgstat_start(void);
extern void pgstat_reset_all(void);
extern void allow_immediate_pgstat_restart(void);

#ifdef EXEC_BACKEND
extern void PgstatCollectorMain(int argc, char *argv[]);
#endif


/* ----------
 * Functions called from backends
 * ----------
 */
extern void pgstat_ping(void);

extern void pgstat_report_stat(bool force);
extern void pgstat_vacuum_stat(void);
extern void pgstat_drop_database(Oid databaseid);

extern void pgstat_clear_snapshot(void);
extern void pgstat_reset_counters(void);

extern void pgstat_report_autovac(Oid dboid);
extern void pgstat_report_vacuum(Oid tableoid, bool shared, bool scanned_all,
                               bool analyze, PgStat_Counter tuples);
extern void pgstat_report_analyze(Relation rel,
                                PgStat_Counter livetuples,
                                PgStat_Counter deadtuples);

extern void pgstat_initialize(void);
extern void pgstat_bestart(void);

extern void pgstat_report_activity(const char *what);
extern void pgstat_report_xact_timestamp(TimestampTz tstamp);
extern void pgstat_report_waiting(bool waiting);
extern const char *pgstat_get_backend_current_activity(int pid, bool checkUser);

extern void pgstat_initstats(Relation rel);

/* nontransactional event counts are simple enough to inline */

#define pgstat_count_heap_scan(rel)                                                 \
      do {                                                                                      \
            if (pgstat_track_counts && (rel)->pgstat_info != NULL)            \
                  (rel)->pgstat_info->t_counts.t_numscans++;                        \
      } while (0)
#define pgstat_count_heap_getnext(rel)                                              \
      do {                                                                                      \
            if (pgstat_track_counts && (rel)->pgstat_info != NULL)            \
                  (rel)->pgstat_info->t_counts.t_tuples_returned++;           \
      } while (0)
#define pgstat_count_heap_fetch(rel)                                                \
      do {                                                                                      \
            if (pgstat_track_counts && (rel)->pgstat_info != NULL)            \
                  (rel)->pgstat_info->t_counts.t_tuples_fetched++;            \
      } while (0)
#define pgstat_count_index_scan(rel)                                                \
      do {                                                                                      \
            if (pgstat_track_counts && (rel)->pgstat_info != NULL)            \
                  (rel)->pgstat_info->t_counts.t_numscans++;                        \
      } while (0)
#define pgstat_count_index_tuples(rel, n)                                     \
      do {                                                                                      \
            if (pgstat_track_counts && (rel)->pgstat_info != NULL)            \
                  (rel)->pgstat_info->t_counts.t_tuples_returned += (n);      \
      } while (0)
#define pgstat_count_buffer_read(rel)                                               \
      do {                                                                                      \
            if (pgstat_track_counts && (rel)->pgstat_info != NULL)            \
                  (rel)->pgstat_info->t_counts.t_blocks_fetched++;            \
      } while (0)
#define pgstat_count_buffer_hit(rel)                                                \
      do {                                                                                      \
            if (pgstat_track_counts && (rel)->pgstat_info != NULL)            \
                  (rel)->pgstat_info->t_counts.t_blocks_hit++;                \
      } while (0)

extern void pgstat_count_heap_insert(Relation rel);
extern void pgstat_count_heap_update(Relation rel, bool hot);
extern void pgstat_count_heap_delete(Relation rel);
extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);

extern void pgstat_init_function_usage(FunctionCallInfoData *fcinfo,
                                                         PgStat_FunctionCallUsage *fcu);
extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
                                                        bool finalize);

extern void AtEOXact_PgStat(bool isCommit);
extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);

extern void AtPrepare_PgStat(void);
extern void PostPrepare_PgStat(void);

extern void pgstat_twophase_postcommit(TransactionId xid, uint16 info,
                                       void *recdata, uint32 len);
extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
                                      void *recdata, uint32 len);

extern void pgstat_send_bgwriter(void);

/* ----------
 * Support functions for the SQL-callable functions to
 * generate the pgstat* views.
 * ----------
 */
extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
extern PgBackendStatus *pgstat_fetch_stat_beentry(int beid);
extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
extern int  pgstat_fetch_stat_numbackends(void);
extern PgStat_GlobalStats *pgstat_fetch_global(void);

#endif   /* PGSTAT_H */

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