and the number of times the background writer stopped a cleaning scan

because it had written too many buffers. Also includes

statistics about the shared buffer pool, including buffers written

by backends (that is, not by the background writer) and total buffers

allocated.

by backends (that is, not by the background writer), how many times

those backends had to execute their own fsync calls (normally the

background writer handles those even when the backend does its own

write), and total buffers allocated.

</entry>

</row>

pg_stat_get_bgwriter_buf_written_clean()AS buffers_clean,

pg_stat_get_bgwriter_maxwritten_clean()AS maxwritten_clean,

pg_stat_get_buf_written_backend()AS buffers_backend,

pg_stat_get_buf_fsync_backend()AS buffers_backend_fsync,

pg_stat_get_buf_alloc()AS buffers_alloc;

intckpt_flags;/* checkpoint flags, as defined in xlog.h */

uint32num_backend_writes;/* counts non-bgwriter buffer writes */

uint32num_backend_fsync;/* counts non-bgwriter fsync calls */

intnum_requests;/* current # of requests */

intmax_requests;/* allocated array size */

LWLockAcquire(BgWriterCommLock,LW_EXCLUSIVE);

BgWriterShmem->num_backend_writes++;

if (BgWriterShmem->bgwriter_pid==0||

BgWriterShmem->num_requests >=BgWriterShmem->max_requests)

{

BgWriterShmem->num_backend_fsync++;

LWLockRelease(BgWriterCommLock);

return false;

}

BgWriterStats.m_buf_written_backend+=BgWriterShmem->num_backend_writes;

BgWriterStats.m_buf_fsync_backend+=BgWriterShmem->num_backend_fsync;

BgWriterShmem->num_backend_writes=0;

BgWriterShmem->num_backend_fsync=0;

n=BgWriterShmem->num_requests;

if (n>0)

globalStats.buf_written_clean+=msg->m_buf_written_clean;

globalStats.maxwritten_clean+=msg->m_maxwritten_clean;

globalStats.buf_written_backend+=msg->m_buf_written_backend;

globalStats.buf_fsync_backend+=msg->m_buf_fsync_backend;

globalStats.buf_alloc+=msg->m_buf_alloc;

}

if (ForwardFsyncRequest(reln->smgr_rnode,forknum,seg->mdfd_segno))

return;/* passed it off successfully */

ereport(DEBUG1,

(errmsg("could not forward fsync request because request queue is full")));

if (FileSync(seg->mdfd_vfd)<0)

ereport(ERROR,

(errcode_for_file_access(),

externDatumpg_stat_get_bgwriter_buf_written_clean(PG_FUNCTION_ARGS);

externDatumpg_stat_get_bgwriter_maxwritten_clean(PG_FUNCTION_ARGS);

externDatumpg_stat_get_buf_written_backend(PG_FUNCTION_ARGS);

externDatumpg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS);

externDatumpg_stat_get_buf_alloc(PG_FUNCTION_ARGS);

externDatumpg_stat_get_xact_numscans(PG_FUNCTION_ARGS);

PG_RETURN_INT64(pgstat_fetch_global()->buf_written_backend);

}

pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS)

{

PG_RETURN_INT64(pgstat_fetch_global()->buf_fsync_backend);

}

pg_stat_get_buf_alloc(PG_FUNCTION_ARGS)

{

DESCR("statistics: number of times the bgwriter stopped processing when it had written too many buffers while cleaning");

DATA(insertOID=2775 (pg_stat_get_buf_written_backendPGNSPPGUID12100ffftfs0020""_null__null__null__null_pg_stat_get_buf_written_backend_null__null__null_ ));

DESCR("statistics: number of buffers written by backends");

DATA(insertOID=3063 (pg_stat_get_buf_fsync_backendPGNSPPGUID12100ffftfs0020""_null__null__null__null_pg_stat_get_buf_fsync_backend_null__null__null_ ));

DESCR("statistics: number of backend buffer writes that did their own fsync");

DATA(insertOID=2859 (pg_stat_get_buf_allocPGNSPPGUID12100ffftfs0020""_null__null__null__null_pg_stat_get_buf_alloc_null__null__null_ ));

DESCR("statistics: number of buffer allocations");

PgStat_Counterm_buf_written_clean;

PgStat_Counterm_maxwritten_clean;

PgStat_Counterm_buf_written_backend;

PgStat_Counterm_buf_fsync_backend;

PgStat_Counterm_buf_alloc;

}PgStat_MsgBgWriter;

PgStat_Counterbuf_written_clean;

PgStat_Countermaxwritten_clean;

PgStat_Counterbuf_written_backend;

PgStat_Counterbuf_fsync_backend;

PgStat_Counterbuf_alloc;

}PgStat_GlobalStats;

pg_stat_activity | SELECT s.datid, d.datname, s.procpid, s.usesysid, u.rolname AS usename, s.application_name, s.client_addr, s.client_port, s.backend_start, s.xact_start, s.query_start, s.waiting, s.current_query FROM pg_database d, pg_stat_get_activity(NULL::integer) s(datid, procpid, usesysid, application_name, current_query, waiting, xact_start, query_start, backend_start, client_addr, client_port), pg_authid u WHERE ((s.datid = d.oid) AND (s.usesysid = u.oid));

pg_stat_all_indexes | SELECT c.oid AS relid, i.oid AS indexrelid, n.nspname AS schemaname, c.relname, i.relname AS indexrelname, pg_stat_get_numscans(i.oid) AS idx_scan, pg_stat_get_tuples_returned(i.oid) AS idx_tup_read, pg_stat_get_tuples_fetched(i.oid) AS idx_tup_fetch FROM (((pg_class c JOIN pg_index x ON ((c.oid = x.indrelid))) JOIN pg_class i ON ((i.oid = x.indexrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = ANY (ARRAY['r'::"char", 't'::"char"]));

pg_stat_all_tables | SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, pg_stat_get_numscans(c.oid) AS seq_scan, pg_stat_get_tuples_returned(c.oid) AS seq_tup_read, (sum(pg_stat_get_numscans(i.indexrelid)))::bigint AS idx_scan, ((sum(pg_stat_get_tuples_fetched(i.indexrelid)))::bigint + pg_stat_get_tuples_fetched(c.oid)) AS idx_tup_fetch, pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS n_tup_upd, pg_stat_get_tuples_deleted(c.oid) AS n_tup_del, pg_stat_get_tuples_hot_updated(c.oid) AS n_tup_hot_upd, pg_stat_get_live_tuples(c.oid) AS n_live_tup, pg_stat_get_dead_tuples(c.oid) AS n_dead_tup, pg_stat_get_last_vacuum_time(c.oid) AS last_vacuum, pg_stat_get_last_autovacuum_time(c.oid) AS last_autovacuum, pg_stat_get_last_analyze_time(c.oid) AS last_analyze, pg_stat_get_last_autoanalyze_time(c.oid) AS last_autoanalyze, pg_stat_get_vacuum_count(c.oid) AS vacuum_count, pg_stat_get_autovacuum_count(c.oid) AS autovacuum_count, pg_stat_get_analyze_count(c.oid) AS analyze_count, pg_stat_get_autoanalyze_count(c.oid) AS autoanalyze_count FROM ((pg_class c LEFT JOIN pg_index i ON ((c.oid = i.indrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = ANY (ARRAY['r'::"char", 't'::"char"])) GROUP BY c.oid, n.nspname, c.relname;

pg_stat_bgwriter | SELECT pg_stat_get_bgwriter_timed_checkpoints() AS checkpoints_timed, pg_stat_get_bgwriter_requested_checkpoints() AS checkpoints_req, pg_stat_get_bgwriter_buf_written_checkpoints() AS buffers_checkpoint, pg_stat_get_bgwriter_buf_written_clean() AS buffers_clean, pg_stat_get_bgwriter_maxwritten_clean() AS maxwritten_clean, pg_stat_get_buf_written_backend() AS buffers_backend, pg_stat_get_buf_alloc() AS buffers_alloc;

pg_stat_bgwriter | SELECT pg_stat_get_bgwriter_timed_checkpoints() AS checkpoints_timed, pg_stat_get_bgwriter_requested_checkpoints() AS checkpoints_req, pg_stat_get_bgwriter_buf_written_checkpoints() AS buffers_checkpoint, pg_stat_get_bgwriter_buf_written_clean() AS buffers_clean, pg_stat_get_bgwriter_maxwritten_clean() AS maxwritten_clean, pg_stat_get_buf_written_backend() AS buffers_backend,pg_stat_get_buf_fsync_backend() AS buffers_backend_fsync,pg_stat_get_buf_alloc() AS buffers_alloc;

pg_stat_database | SELECT d.oid AS datid, d.datname, pg_stat_get_db_numbackends(d.oid) AS numbackends, pg_stat_get_db_xact_commit(d.oid) AS xact_commit, pg_stat_get_db_xact_rollback(d.oid) AS xact_rollback, (pg_stat_get_db_blocks_fetched(d.oid) - pg_stat_get_db_blocks_hit(d.oid)) AS blks_read, pg_stat_get_db_blocks_hit(d.oid) AS blks_hit, pg_stat_get_db_tuples_returned(d.oid) AS tup_returned, pg_stat_get_db_tuples_fetched(d.oid) AS tup_fetched, pg_stat_get_db_tuples_inserted(d.oid) AS tup_inserted, pg_stat_get_db_tuples_updated(d.oid) AS tup_updated, pg_stat_get_db_tuples_deleted(d.oid) AS tup_deleted FROM pg_database d;

pg_stat_sys_indexes | SELECT pg_stat_all_indexes.relid, pg_stat_all_indexes.indexrelid, pg_stat_all_indexes.schemaname, pg_stat_all_indexes.relname, pg_stat_all_indexes.indexrelname, pg_stat_all_indexes.idx_scan, pg_stat_all_indexes.idx_tup_read, pg_stat_all_indexes.idx_tup_fetch FROM pg_stat_all_indexes WHERE ((pg_stat_all_indexes.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_indexes.schemaname ~ '^pg_toast'::text));

pg_stat_sys_tables | SELECT pg_stat_all_tables.relid, pg_stat_all_tables.schemaname, pg_stat_all_tables.relname, pg_stat_all_tables.seq_scan, pg_stat_all_tables.seq_tup_read, pg_stat_all_tables.idx_scan, pg_stat_all_tables.idx_tup_fetch, pg_stat_all_tables.n_tup_ins, pg_stat_all_tables.n_tup_upd, pg_stat_all_tables.n_tup_del, pg_stat_all_tables.n_tup_hot_upd, pg_stat_all_tables.n_live_tup, pg_stat_all_tables.n_dead_tup, pg_stat_all_tables.last_vacuum, pg_stat_all_tables.last_autovacuum, pg_stat_all_tables.last_analyze, pg_stat_all_tables.last_autoanalyze, pg_stat_all_tables.vacuum_count, pg_stat_all_tables.autovacuum_count, pg_stat_all_tables.analyze_count, pg_stat_all_tables.autoanalyze_count FROM pg_stat_all_tables WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));