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Various improvements of skipping index scan during vacuum technics

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- Change vacuum_cleanup_index_scale_factor GUC to PGC_USERSET.
  vacuum_cleanup_index_scale_factor GUC was defined as PGC_SIGHUP.  But this
  GUC affects not only autovacuum.  So it might be useful to change it from user
  session in order to influence manually runned VACUUM.
- Add missing tab-complete support for vacuum_cleanup_index_scale_factor
  reloption.
- Fix condition for B-tree index cleanup.
  Zero value of vacuum_cleanup_index_scale_factor means that user wants B-tree
  index cleanup to be never skipped.
- Documentation and comment improvements

Authors: Justin Pryzby, Alexander Korotkov, Liudmila Mantrova
Reviewed by: all authors and Robert Haas
Discussion: https://www.postgresql.org/message-id/flat/20180502023025.GD7631%40telsasoft.com
This commit is contained in:
Teodor Sigaev
2018-05-10 13:31:47 +03:00
parent ddc1f32ee5
commit 8e12f4a250
5 changed files with 43 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
src/backend/access/nbtree/nbtpage.c
View File

@ -189,7 +189,7 @@ _bt_update_meta_cleanup_info(Relation rel, TransactionId oldestBtpoXact,
if (metad->btm_version < BTREE_VERSION)
_bt_upgrademetapage(metapg);
/* update cleanup-related infromation */
/* update cleanup-related information */
metad->btm_oldest_btpo_xact = oldestBtpoXact;
metad->btm_last_cleanup_num_heap_tuples = numHeapTuples;
MarkBufferDirty(metabuf);

19
src/backend/access/nbtree/nbtree.c
View File

@ -818,10 +818,11 @@ _bt_vacuum_needs_cleanup(IndexVacuumInfo *info)
float8 cleanup_scale_factor;
/*
* If table receives large enough amount of insertions and no cleanup
* was performed, then index might appear to have stalled statistics.
* In order to evade that, we perform cleanup when table receives
* vacuum_cleanup_index_scale_factor fractions of insertions.
* If table receives enough insertions and no cleanup was performed,
* then index would appear have stale statistics. If scale factor
* is set, we avoid that by performing cleanup if the number of
* inserted tuples exceeds vacuum_cleanup_index_scale_factor fraction
* of original tuples count.
*/
relopts = (StdRdOptions *) info->index->rd_options;
cleanup_scale_factor = (relopts &&
@ -829,7 +830,7 @@ _bt_vacuum_needs_cleanup(IndexVacuumInfo *info)
? relopts->vacuum_cleanup_index_scale_factor
: vacuum_cleanup_index_scale_factor;
if (cleanup_scale_factor < 0 ||
if (cleanup_scale_factor <= 0 ||
metad->btm_last_cleanup_num_heap_tuples < 0 ||
info->num_heap_tuples > (1.0 + cleanup_scale_factor) *
metad->btm_last_cleanup_num_heap_tuples)
@ -870,8 +871,8 @@ btbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
&oldestBtpoXact);
/*
* Update cleanup-related information in metapage. These information
* is used only for cleanup but keeping up them to date can avoid
* Update cleanup-related information in metapage. This information
* is used only for cleanup but keeping them up to date can avoid
* unnecessary cleanup even after bulkdelete.
*/
_bt_update_meta_cleanup_info(info->index, oldestBtpoXact,
@ -899,8 +900,8 @@ btvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
* If btbulkdelete was called, we need not do anything, just return the
* stats from the latest btbulkdelete call. If it wasn't called, we might
* still need to do a pass over the index, to recycle any newly-recyclable
* pages and to obtain index statistics. _bt_vacuum_needs_cleanup checks
* is there are newly-recyclable or stalled index statistics.
* pages or to obtain index statistics. _bt_vacuum_needs_cleanup
* determines if either are needed.
*
* Since we aren't going to actually delete any leaf items, there's no
* need to go through all the vacuum-cycle-ID pushups.

2
src/backend/utils/misc/guc.c
View File

@ -3238,7 +3238,7 @@ static struct config_real ConfigureNamesReal[] =
},
{
{"vacuum_cleanup_index_scale_factor", PGC_SIGHUP, AUTOVACUUM,
{"vacuum_cleanup_index_scale_factor", PGC_USERSET, AUTOVACUUM,
gettext_noop("Number of tuple inserts prior to index cleanup as a fraction of reltuples."),
NULL
},

6
src/bin/psql/tab-complete.c
View File

@ -1855,13 +1855,15 @@ psql_completion(const char *text, int start, int end)
COMPLETE_WITH_CONST("(");
/* ALTER INDEX <foo> SET|RESET ( */
else if (Matches5("ALTER", "INDEX", MatchAny, "RESET", "("))
COMPLETE_WITH_LIST7("fillfactor", "recheck_on_update",
COMPLETE_WITH_LIST8("fillfactor", "recheck_on_update",
"vacuum_cleanup_index_scale_factor", /* BTREE */
"fastupdate", "gin_pending_list_limit", /* GIN */
"buffering", /* GiST */
"pages_per_range", "autosummarize" /* BRIN */
);
else if (Matches5("ALTER", "INDEX", MatchAny, "SET", "("))
COMPLETE_WITH_LIST7("fillfactor =", "recheck_on_update =",
COMPLETE_WITH_LIST8("fillfactor =", "recheck_on_update =",
"vacuum_cleanup_index_scale_factor =", /* BTREE */
"fastupdate =", "gin_pending_list_limit =", /* GIN */
"buffering =", /* GiST */
"pages_per_range =", "autosummarize =" /* BRIN */