From efe635b934bd1e2ff280ccf66a7e6e15424566c9 Mon Sep 17 00:00:00 2001 From: Amit Kapila Date: Fri, 3 Apr 2020 18:51:51 +0530 Subject: [PATCH v14 3/4] Allow pg_stat_statements to track WAL usage statistics. This commit adds three new columns in pg_stat_statements output to display WAL usage statistics added by commit <>. This commit doesn't bump the version of pg_stat_statements as the same is done for this release in commit 17e0328224. Author: Kirill Bychik and Julien Rouhaud Reviewed-by: Julien Rouhaud, Fujii Masao, Dilip Kumar and Amit Kapila Discussion: https://postgr.es/m/CAB-hujrP8ZfUkvL5OYETipQwA=e3n7oqHFU=4ZLxWS_Cza3kQQ@mail.gmail.com --- .../expected/pg_stat_statements.out | 39 +++++++++++++++ .../pg_stat_statements--1.7--1.8.sql | 5 +- contrib/pg_stat_statements/pg_stat_statements.c | 55 ++++++++++++++++++++-- .../pg_stat_statements/sql/pg_stat_statements.sql | 23 +++++++++ doc/src/sgml/pgstatstatements.sgml | 27 +++++++++++ 5 files changed, 145 insertions(+), 4 deletions(-) diff --git a/contrib/pg_stat_statements/expected/pg_stat_statements.out b/contrib/pg_stat_statements/expected/pg_stat_statements.out index 45dbe9e..f615f8c 100644 --- a/contrib/pg_stat_statements/expected/pg_stat_statements.out +++ b/contrib/pg_stat_statements/expected/pg_stat_statements.out @@ -212,6 +212,45 @@ SELECT query, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C"; (10 rows) -- +-- INSERT, UPDATE, DELETE on test table to validate WAL generation metrics +-- +SELECT pg_stat_statements_reset(); + pg_stat_statements_reset +-------------------------- + +(1 row) + +-- utility "create table" should not be shown +CREATE TABLE pgss_test (a int, b char(20)); +INSERT INTO pgss_test VALUES(generate_series(1, 10), 'aaa'); +UPDATE pgss_test SET b = 'bbb' WHERE a > 7; +DELETE FROM pgss_test WHERE a > 9; +-- DROP test table +SET pg_stat_statements.track_utility = TRUE; +DROP TABLE pgss_test; +SET pg_stat_statements.track_utility = FALSE; +-- Check WAL is generated for the above statements +SELECT query, calls, rows, +wal_bytes > 0 as wal_bytes_generated, +wal_records > 0 as wal_records_generated, +wal_records = rows as wal_records_as_rows +FROM pg_stat_statements ORDER BY query COLLATE "C"; + query | calls | rows | wal_bytes_generated | wal_records_generated | wal_records_as_rows +-----------------------------------------------------------+-------+------+---------------------+-----------------------+--------------------- + DELETE FROM pgss_test WHERE a > $1 | 1 | 1 | t | t | t + DROP TABLE pgss_test | 1 | 0 | t | t | f + INSERT INTO pgss_test VALUES(generate_series($1, $2), $3) | 1 | 10 | t | t | t + SELECT pg_stat_statements_reset() | 1 | 1 | f | f | f + SELECT query, calls, rows, +| 0 | 0 | f | f | t + wal_bytes > $1 as wal_bytes_generated, +| | | | | + wal_records > $2 as wal_records_generated, +| | | | | + wal_records = rows as wal_records_as_rows +| | | | | + FROM pg_stat_statements ORDER BY query COLLATE "C" | | | | | + SET pg_stat_statements.track_utility = FALSE | 1 | 0 | f | f | t + UPDATE pgss_test SET b = $1 WHERE a > $2 | 1 | 3 | t | t | t +(7 rows) + +-- -- pg_stat_statements.track = none -- SET pg_stat_statements.track = 'none'; diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql b/contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql index 60d454d..3056657 100644 --- a/contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql +++ b/contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql @@ -41,7 +41,10 @@ CREATE FUNCTION pg_stat_statements(IN showtext boolean, OUT temp_blks_read int8, OUT temp_blks_written int8, OUT blk_read_time float8, - OUT blk_write_time float8 + OUT blk_write_time float8, + OUT wal_records int8, + OUT wal_num_fpw int8, + OUT wal_bytes numeric ) RETURNS SETOF record AS 'MODULE_PATHNAME', 'pg_stat_statements_1_8' diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c index 942922b..04abdab 100644 --- a/contrib/pg_stat_statements/pg_stat_statements.c +++ b/contrib/pg_stat_statements/pg_stat_statements.c @@ -188,6 +188,9 @@ typedef struct Counters double blk_read_time; /* time spent reading, in msec */ double blk_write_time; /* time spent writing, in msec */ double usage; /* usage factor */ + int64 wal_records; /* # of WAL records generated */ + int64 wal_num_fpw; /* # of WAL full page image records generated */ + uint64 wal_bytes; /* total amount of WAL bytes generated */ } Counters; /* @@ -348,6 +351,7 @@ static void pgss_store(const char *query, uint64 queryId, pgssStoreKind kind, double total_time, uint64 rows, const BufferUsage *bufusage, + const WalUsage *walusage, pgssJumbleState *jstate); static void pg_stat_statements_internal(FunctionCallInfo fcinfo, pgssVersion api_version, @@ -891,6 +895,7 @@ pgss_post_parse_analyze(ParseState *pstate, Query *query) 0, 0, NULL, + NULL, &jstate); } @@ -926,9 +931,17 @@ pgss_planner(Query *parse, instr_time duration; BufferUsage bufusage_start, bufusage; + WalUsage walusage_start, + walusage; /* We need to track buffer usage as the planner can access them. */ bufusage_start = pgBufferUsage; + + /* + * Similarly the planner could write some WAL records in some cases + * (e.g. setting a hint bit with those being WAL-logged) + */ + walusage_start = pgWalUsage; INSTR_TIME_SET_CURRENT(start); plan_nested_level++; @@ -954,6 +967,10 @@ pgss_planner(Query *parse, memset(&bufusage, 0, sizeof(BufferUsage)); BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start); + /* calc differences of WAL counters. */ + memset(&walusage, 0, sizeof(WalUsage)); + WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start); + pgss_store(query_string, parse->queryId, parse->stmt_location, @@ -962,6 +979,7 @@ pgss_planner(Query *parse, INSTR_TIME_GET_MILLISEC(duration), 0, &bufusage, + &walusage, NULL); } else @@ -1079,6 +1097,7 @@ pgss_ExecutorEnd(QueryDesc *queryDesc) queryDesc->totaltime->total * 1000.0, /* convert to msec */ queryDesc->estate->es_processed, &queryDesc->totaltime->bufusage, + &queryDesc->totaltime->walusage, NULL); } @@ -1123,8 +1142,11 @@ pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString, uint64 rows; BufferUsage bufusage_start, bufusage; + WalUsage walusage_start, + walusage; bufusage_start = pgBufferUsage; + walusage_start = pgWalUsage; INSTR_TIME_SET_CURRENT(start); exec_nested_level++; @@ -1154,6 +1176,10 @@ pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString, memset(&bufusage, 0, sizeof(BufferUsage)); BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start); + /* calc differences of WAL counters. */ + memset(&walusage, 0, sizeof(WalUsage)); + WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start); + pgss_store(queryString, 0, /* signal that it's a utility stmt */ pstmt->stmt_location, @@ -1162,6 +1188,7 @@ pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString, INSTR_TIME_GET_MILLISEC(duration), rows, &bufusage, + &walusage, NULL); } else @@ -1197,7 +1224,8 @@ pgss_hash_string(const char *str, int len) * * If jstate is not NULL then we're trying to create an entry for which * we have no statistics as yet; we just want to record the normalized - * query string. total_time, rows, bufusage are ignored in this case. + * query string. total_time, rows, bufusage and walusage are ignored in this + * case. * * If kind is PGSS_PLAN or PGSS_EXEC, its value is used as the array position * for the arrays in the Counters field. @@ -1208,6 +1236,7 @@ pgss_store(const char *query, uint64 queryId, pgssStoreKind kind, double total_time, uint64 rows, const BufferUsage *bufusage, + const WalUsage *walusage, pgssJumbleState *jstate) { pgssHashKey key; @@ -1402,6 +1431,9 @@ pgss_store(const char *query, uint64 queryId, e->counters.blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_read_time); e->counters.blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_write_time); e->counters.usage += USAGE_EXEC(total_time); + e->counters.wal_records += walusage->wal_records; + e->counters.wal_num_fpw += walusage->wal_num_fpw; + e->counters.wal_bytes += walusage->wal_bytes; SpinLockRelease(&e->mutex); } @@ -1449,8 +1481,8 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS) #define PG_STAT_STATEMENTS_COLS_V1_1 18 #define PG_STAT_STATEMENTS_COLS_V1_2 19 #define PG_STAT_STATEMENTS_COLS_V1_3 23 -#define PG_STAT_STATEMENTS_COLS_V1_8 29 -#define PG_STAT_STATEMENTS_COLS 29 /* maximum of above */ +#define PG_STAT_STATEMENTS_COLS_V1_8 32 +#define PG_STAT_STATEMENTS_COLS 32 /* maximum of above */ /* * Retrieve statement statistics. @@ -1786,6 +1818,23 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, values[i++] = Float8GetDatumFast(tmp.blk_read_time); values[i++] = Float8GetDatumFast(tmp.blk_write_time); } + if (api_version >= PGSS_V1_8) + { + char buf[256]; + Datum wal_bytes; + + values[i++] = Int64GetDatumFast(tmp.wal_records); + values[i++] = Int64GetDatumFast(tmp.wal_num_fpw); + + snprintf(buf, sizeof buf, UINT64_FORMAT, tmp.wal_bytes); + + /* Convert to numeric. */ + wal_bytes = DirectFunctionCall3(numeric_in, + CStringGetDatum(buf), + ObjectIdGetDatum(0), + Int32GetDatum(-1)); + values[i++] = wal_bytes; + } Assert(i == (api_version == PGSS_V1_0 ? PG_STAT_STATEMENTS_COLS_V1_0 : api_version == PGSS_V1_1 ? PG_STAT_STATEMENTS_COLS_V1_1 : diff --git a/contrib/pg_stat_statements/sql/pg_stat_statements.sql b/contrib/pg_stat_statements/sql/pg_stat_statements.sql index 435d510..75c1055 100644 --- a/contrib/pg_stat_statements/sql/pg_stat_statements.sql +++ b/contrib/pg_stat_statements/sql/pg_stat_statements.sql @@ -102,6 +102,29 @@ SELECT * FROM test WHERE a IN (1, 2, 3, 4, 5); SELECT query, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C"; -- +-- INSERT, UPDATE, DELETE on test table to validate WAL generation metrics +-- +SELECT pg_stat_statements_reset(); + +-- utility "create table" should not be shown +CREATE TABLE pgss_test (a int, b char(20)); + +INSERT INTO pgss_test VALUES(generate_series(1, 10), 'aaa'); +UPDATE pgss_test SET b = 'bbb' WHERE a > 7; +DELETE FROM pgss_test WHERE a > 9; +-- DROP test table +SET pg_stat_statements.track_utility = TRUE; +DROP TABLE pgss_test; +SET pg_stat_statements.track_utility = FALSE; + +-- Check WAL is generated for the above statements +SELECT query, calls, rows, +wal_bytes > 0 as wal_bytes_generated, +wal_records > 0 as wal_records_generated, +wal_records = rows as wal_records_as_rows +FROM pg_stat_statements ORDER BY query COLLATE "C"; + +-- -- pg_stat_statements.track = none -- SET pg_stat_statements.track = 'none'; diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml index b4df84c..3d26108 100644 --- a/doc/src/sgml/pgstatstatements.sgml +++ b/doc/src/sgml/pgstatstatements.sgml @@ -264,6 +264,33 @@ + + wal_bytes + numeric + + + Total amount of WAL bytes generated by the statement + + + + + wal_records + bigint + + + Total count of WAL records generated by the statement + + + + + wal_num_fpw + bigint + + + Total count of WAL full page writes generated by the statement + + + -- 1.8.3.1