diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/test/regress/expected/stats.out | 30 | ||||
| -rw-r--r-- | src/test/regress/sql/stats.sql | 19 |
2 files changed, 32 insertions, 17 deletions
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index 8e633407829..319164a5e9e 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1385,7 +1385,11 @@ SELECT :io_sum_local_new_tblspc_writes > :io_sum_local_after_writes; RESET temp_buffers; -- Test that reuse of strategy buffers and reads of blocks into these reused --- buffers while VACUUMing are tracked in pg_stat_io. +-- buffers while VACUUMing are tracked in pg_stat_io. If there is sufficient +-- demand for shared buffers from concurrent queries, some buffers may be +-- pinned by other backends before they can be reused. In such cases, the +-- backend will evict a buffer from outside the ring and add it to the +-- ring. This is considered an eviction and not a reuse. -- Set wal_skip_threshold smaller than the expected size of -- test_io_vac_strategy so that, even if wal_level is minimal, VACUUM FULL will -- fsync the newly rewritten test_io_vac_strategy instead of writing it to WAL. @@ -1393,15 +1397,15 @@ RESET temp_buffers; -- shared buffers -- preventing us from testing BAS_VACUUM BufferAccessStrategy -- reads. SET wal_skip_threshold = '1 kB'; -SELECT sum(reuses) AS reuses, sum(reads) AS reads +SELECT sum(reuses) AS reuses, sum(reads) AS reads, sum(evictions) AS evictions 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, 4500)i; -- Ensure that the next VACUUM will need to perform IO by rewriting the table -- first with VACUUM (FULL). VACUUM (FULL) test_io_vac_strategy; --- Use the minimum BUFFER_USAGE_LIMIT to cause reuses with the smallest table --- possible. +-- Use the minimum BUFFER_USAGE_LIMIT to cause reuses or evictions with the +-- smallest table possible. VACUUM (PARALLEL 0, BUFFER_USAGE_LIMIT 128) test_io_vac_strategy; SELECT pg_stat_force_next_flush(); pg_stat_force_next_flush @@ -1409,13 +1413,19 @@ SELECT pg_stat_force_next_flush(); (1 row) -SELECT sum(reuses) AS reuses, sum(reads) AS reads +SELECT sum(reuses) AS reuses, sum(reads) AS reads, sum(evictions) AS evictions 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; - ?column? | ?column? -----------+---------- - t | t +SELECT :io_sum_vac_strategy_after_reads > :io_sum_vac_strategy_before_reads; + ?column? +---------- + t +(1 row) + +SELECT (:io_sum_vac_strategy_after_reuses + :io_sum_vac_strategy_after_evictions) > + (:io_sum_vac_strategy_before_reuses + :io_sum_vac_strategy_before_evictions); + ?column? +---------- + t (1 row) RESET wal_skip_threshold; diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index fddf5a8277d..9a16df1c498 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -678,7 +678,11 @@ SELECT :io_sum_local_new_tblspc_writes > :io_sum_local_after_writes; RESET temp_buffers; -- Test that reuse of strategy buffers and reads of blocks into these reused --- buffers while VACUUMing are tracked in pg_stat_io. +-- buffers while VACUUMing are tracked in pg_stat_io. If there is sufficient +-- demand for shared buffers from concurrent queries, some buffers may be +-- pinned by other backends before they can be reused. In such cases, the +-- backend will evict a buffer from outside the ring and add it to the +-- ring. This is considered an eviction and not a reuse. -- Set wal_skip_threshold smaller than the expected size of -- test_io_vac_strategy so that, even if wal_level is minimal, VACUUM FULL will @@ -687,21 +691,22 @@ RESET temp_buffers; -- shared buffers -- preventing us from testing BAS_VACUUM BufferAccessStrategy -- reads. SET wal_skip_threshold = '1 kB'; -SELECT sum(reuses) AS reuses, sum(reads) AS reads +SELECT sum(reuses) AS reuses, sum(reads) AS reads, sum(evictions) AS evictions 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, 4500)i; -- Ensure that the next VACUUM will need to perform IO by rewriting the table -- first with VACUUM (FULL). VACUUM (FULL) test_io_vac_strategy; --- Use the minimum BUFFER_USAGE_LIMIT to cause reuses with the smallest table --- possible. +-- Use the minimum BUFFER_USAGE_LIMIT to cause reuses or evictions with the +-- smallest table possible. VACUUM (PARALLEL 0, BUFFER_USAGE_LIMIT 128) test_io_vac_strategy; SELECT pg_stat_force_next_flush(); -SELECT sum(reuses) AS reuses, sum(reads) AS reads +SELECT sum(reuses) AS reuses, sum(reads) AS reads, sum(evictions) AS evictions 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; +SELECT :io_sum_vac_strategy_after_reads > :io_sum_vac_strategy_before_reads; +SELECT (:io_sum_vac_strategy_after_reuses + :io_sum_vac_strategy_after_evictions) > + (:io_sum_vac_strategy_before_reuses + :io_sum_vac_strategy_before_evictions); RESET wal_skip_threshold; -- Test that extends done by a CTAS, which uses a BAS_BULKWRITE |