diff options
| author | Thomas Munro | 2021-04-08 11:03:43 +0000 |
|---|---|---|
| committer | Thomas Munro | 2021-04-08 11:20:42 +0000 |
| commit | 1d257577e08d3e598011d6850fd1025858de8c8c (patch) | |
| tree | 1c2ac92489fe1e54cdc0837dec9b84d17434c4b7 /src/test | |
| parent | f003d9f8721b3249e4aec8a1946034579d40d42c (diff) | |
Optionally prefetch referenced data in recovery.
Introduce a new GUC recovery_prefetch, disabled by default. When
enabled, look ahead in the WAL and try to initiate asynchronous reading
of referenced data blocks that are not yet cached in our buffer pool.
For now, this is done with posix_fadvise(), which has several caveats.
Better mechanisms will follow in later work on the I/O subsystem.
The GUC maintenance_io_concurrency is used to limit the number of
concurrent I/Os we allow ourselves to initiate, based on pessimistic
heuristics used to infer that I/Os have begun and completed.
The GUC wal_decode_buffer_size is used to limit the maximum distance we
are prepared to read ahead in the WAL to find uncached blocks.
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> (parts)
Reviewed-by: Andres Freund <andres@anarazel.de> (parts)
Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> (parts)
Tested-by: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Tested-by: Jakub Wartak <Jakub.Wartak@tomtom.com>
Tested-by: Dmitry Dolgov <9erthalion6@gmail.com>
Tested-by: Sait Talha Nisanci <Sait.Nisanci@microsoft.com>
Discussion: https://postgr.es/m/CA%2BhUKGJ4VJN8ttxScUFM8dOKX0BrBiboo5uz1cq%3DAovOddfHpA%40mail.gmail.com
Diffstat (limited to 'src/test')
| -rw-r--r-- | src/test/regress/expected/rules.out | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index a8a1cc72d0d..186e6c966c6 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1879,6 +1879,17 @@ pg_stat_gssapi| SELECT s.pid, s.gss_enc AS encrypted FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, queryid) WHERE (s.client_port IS NOT NULL); +pg_stat_prefetch_recovery| SELECT s.stats_reset, + s.prefetch, + s.skip_hit, + s.skip_new, + s.skip_fpw, + s.skip_seq, + s.distance, + s.queue_depth, + s.avg_distance, + s.avg_queue_depth + FROM pg_stat_get_prefetch_recovery() s(stats_reset, prefetch, skip_hit, skip_new, skip_fpw, skip_seq, distance, queue_depth, avg_distance, avg_queue_depth); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, |