@ -549,15 +549,15 @@ SELECT pg_stat_get_subscription_stats(NULL);
-- Create a regular table and insert some data to generate IOCONTEXT_NORMAL
-- extends.
SELECT sum ( extends ) AS io_sum_shared_before_extends
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' relation ' \ gset
SELECT sum ( writes ) AS writes , sum ( fsyncs ) AS fsyncs
FROM pg_stat_io
WHERE io_ object = ' relation ' \ gset io_sum_shared_before_
WHERE object = ' relation ' \ gset io_sum_shared_before_
CREATE TABLE test_io_shared ( a int ) ;
INSERT INTO test_io_shared SELECT i FROM generate_series ( 1 , 100 ) i ;
SELECT pg_stat_force_next_flush ( ) ;
SELECT sum ( extends ) AS io_sum_shared_after_extends
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' relation ' \ gset
SELECT : io_sum_shared_after_extends > : io_sum_shared_before_extends ;
-- After a checkpoint, there should be some additional IOCONTEXT_NORMAL writes
@ -567,7 +567,7 @@ CHECKPOINT;
CHECKPOINT ;
SELECT sum ( writes ) AS writes , sum ( fsyncs ) AS fsyncs
FROM pg_stat_io
WHERE io_ object = ' relation ' \ gset io_sum_shared_after_
WHERE object = ' relation ' \ gset io_sum_shared_after_
SELECT : io_sum_shared_after_writes > : io_sum_shared_before_writes ;
SELECT current_setting ( ' fsync ' ) = ' off '
OR : io_sum_shared_after_fsyncs > : io_sum_shared_before_fsyncs ;
@ -575,22 +575,22 @@ SELECT current_setting('fsync') = 'off'
-- Change the tablespace so that the table is rewritten directly, then SELECT
-- from it to cause it to be read back into shared buffers.
SELECT sum ( reads ) AS io_sum_shared_before_reads
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' relation ' \ gset
-- Do this in a transaction to prevent spurious failures due to concurrent accesses to our newly
-- rewritten table, e.g. by autovacuum.
BEGIN ;
ALTER TABLE test_io_shared SET TABLESPACE regress_tblspace ;
-- SELECT from the table so that the data is read into shared buffers and
-- io_ context 'normal', io_ object 'relation' reads are counted.
-- context 'normal', object 'relation' reads are counted.
SELECT COUNT ( * ) FROM test_io_shared ;
COMMIT ;
SELECT pg_stat_force_next_flush ( ) ;
SELECT sum ( reads ) AS io_sum_shared_after_reads
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' relation ' \ gset
SELECT : io_sum_shared_after_reads > : io_sum_shared_before_reads ;
SELECT sum ( hits ) AS io_sum_shared_before_hits
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' relation ' \ gset
-- Select from the table again to count hits.
-- Ensure we generate hits by forcing a nested loop self-join with no
-- materialize node. The outer side's buffer will stay pinned, preventing its
@ -604,7 +604,7 @@ SELECT COUNT(*) FROM test_io_shared t1 INNER JOIN test_io_shared t2 USING (a);
COMMIT ;
SELECT pg_stat_force_next_flush ( ) ;
SELECT sum ( hits ) AS io_sum_shared_after_hits
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' relation ' \ gset
SELECT : io_sum_shared_after_hits > : io_sum_shared_before_hits ;
DROP TABLE test_io_shared ;
@ -623,7 +623,7 @@ SET temp_buffers TO 100;
CREATE TEMPORARY TABLE test_io_local ( a int , b TEXT ) ;
SELECT sum ( extends ) AS extends , sum ( evictions ) AS evictions , sum ( writes ) AS writes
FROM pg_stat_io
WHERE io_ context = ' normal ' AND io_ object = ' temp relation ' \ gset io_sum_local_before_
WHERE context = ' normal ' AND object = ' temp relation ' \ gset io_sum_local_before_
-- Insert tuples into the temporary table, generating extends in the stats.
-- Insert enough values that we need to reuse and write out dirty local
-- buffers, generating evictions and writes.
@ -632,7 +632,7 @@ INSERT INTO test_io_local SELECT generate_series(1, 5000) as id, repeat('a', 200
SELECT pg_relation_size ( ' test_io_local ' ) / current_setting ( ' block_size ' ) : : int8 > 100 ;
SELECT sum ( reads ) AS io_sum_local_before_reads
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' temp relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' temp relation ' \ gset
-- Read in evicted buffers, generating reads.
SELECT COUNT ( * ) FROM test_io_local ;
SELECT pg_stat_force_next_flush ( ) ;
@ -641,7 +641,7 @@ SELECT sum(evictions) AS evictions,
sum ( writes ) AS writes ,
sum ( extends ) AS extends
FROM pg_stat_io
WHERE io_ context = ' normal ' AND io_ object = ' temp relation ' \ gset io_sum_local_after_
WHERE context = ' normal ' AND object = ' temp relation ' \ gset io_sum_local_after_
SELECT : io_sum_local_after_evictions > : io_sum_local_before_evictions ,
: io_sum_local_after_reads > : io_sum_local_before_reads ,
: io_sum_local_after_writes > : io_sum_local_before_writes ,
@ -653,7 +653,7 @@ SELECT :io_sum_local_after_evictions > :io_sum_local_before_evictions,
ALTER TABLE test_io_local SET TABLESPACE regress_tblspace ;
SELECT pg_stat_force_next_flush ( ) ;
SELECT sum ( writes ) AS io_sum_local_new_tblspc_writes
FROM pg_stat_io WHERE io_ context = ' normal ' AND io_ object = ' temp relation ' \ gset
FROM pg_stat_io WHERE context = ' normal ' AND object = ' temp relation ' \ gset
SELECT : io_sum_local_new_tblspc_writes > : io_sum_local_after_writes ;
RESET temp_buffers ;
@ -668,7 +668,7 @@ RESET temp_buffers;
-- reads.
SET wal_skip_threshold = ' 1 kB ' ;
SELECT sum ( reuses ) AS reuses , sum ( reads ) AS reads
FROM pg_stat_io WHERE io_ context = ' vacuum ' \ gset io_sum_vac_strategy_before_
FROM pg_stat_io WHERE context = ' vacuum ' \ gset io_sum_vac_strategy_before_
CREATE TABLE test_io_vac_strategy ( a int , b int ) WITH ( autovacuum_enabled = ' false ' ) ;
INSERT INTO test_io_vac_strategy SELECT i , i from generate_series ( 1 , 8000 ) i ;
-- Ensure that the next VACUUM will need to perform IO by rewriting the table
@ -677,7 +677,7 @@ VACUUM (FULL) test_io_vac_strategy;
VACUUM ( PARALLEL 0 ) test_io_vac_strategy ;
SELECT pg_stat_force_next_flush ( ) ;
SELECT sum ( reuses ) AS reuses , sum ( reads ) AS reads
FROM pg_stat_io WHERE io_ context = ' vacuum ' \ gset io_sum_vac_strategy_after_
FROM pg_stat_io WHERE context = ' vacuum ' \ gset io_sum_vac_strategy_after_
SELECT : io_sum_vac_strategy_after_reads > : io_sum_vac_strategy_before_reads ,
: io_sum_vac_strategy_after_reuses > : io_sum_vac_strategy_before_reuses ;
RESET wal_skip_threshold ;
@ -685,11 +685,11 @@ RESET wal_skip_threshold;
-- Test that extends done by a CTAS, which uses a BAS_BULKWRITE
-- BufferAccessStrategy, are tracked in pg_stat_io.
SELECT sum ( extends ) AS io_sum_bulkwrite_strategy_extends_before
FROM pg_stat_io WHERE io_ context = ' bulkwrite ' \ gset
FROM pg_stat_io WHERE context = ' bulkwrite ' \ gset
CREATE TABLE test_io_bulkwrite_strategy AS SELECT i FROM generate_series ( 1 , 100 ) i ;
SELECT pg_stat_force_next_flush ( ) ;
SELECT sum ( extends ) AS io_sum_bulkwrite_strategy_extends_after
FROM pg_stat_io WHERE io_ context = ' bulkwrite ' \ gset
FROM pg_stat_io WHERE context = ' bulkwrite ' \ gset
SELECT : io_sum_bulkwrite_strategy_extends_after > : io_sum_bulkwrite_strategy_extends_before ;
-- Test IO stats reset
Michael Paquier
3 years ago