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  • Committer: Bazaar Package Importer
  • Author(s): Martin Pitt
  • Date: 2009-07-01 17:41:41 UTC
  • mfrom: (1.1.4 upstream)
  • mto: This revision was merged to the branch mainline in revision 6.
  • Revision ID: james.westby@ubuntu.com-20090701174141-jfmn9tt8e69m950x
Tags: 8.4.0-1
* Final 8.4.0 release. Major enhancements:
  - Windowing Functions
  - Common Table Expressions and Recursive Queries
  - Default and variadic parameters for functions
  - Parallel Restore
  - Column Permissions
  - Per-database locale settings
  - Improved hash indexes
  - Improved join performance for EXISTS and NOT EXISTS queries
  - Easier-to-use Warm Standby
  - Automatic sizing of the Free Space Map
  - Visibility Map (greatly reduces vacuum overhead for slowly-changing
    tables)
  - Version-aware psql (backslash commands work against older servers)
  - Support SSL certificates for user authentication
  - Per-function runtime statistics
  - Easy editing of functions in psql
  - New contrib modules: pg_stat_statements, auto_explain, citext,
    btree_gin 
  Upload to unstable, 8.4 is the new default. 
* debian/control: Build the versionless metapackages and have them point to
  8.4.

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src/backend/commands/vacuumlazy.c
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 *
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 *
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 * IDENTIFICATION
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 *        $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.119 2009/03/24 20:17:14 tgl Exp $
 
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 *        $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.121 2009/06/11 14:48:56 momjian Exp $
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 *
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 *-------------------------------------------------------------------------
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 */
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{
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        /* hasindex = true means two-pass strategy; false means one-pass */
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        bool            hasindex;
 
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        bool            scanned_all;    /* have we scanned all pages (this far)? */
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        /* Overall statistics about rel */
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        BlockNumber rel_pages;
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        double          rel_tuples;
 
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        double          old_rel_tuples; /* previous value of pg_class.reltuples */
 
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        double          rel_tuples;             /* counts only tuples on scanned pages */
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        BlockNumber pages_removed;
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        double          tuples_deleted;
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        BlockNumber nonempty_pages; /* actually, last nonempty page + 1 */
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        int                     max_dead_tuples;        /* # slots allocated in array */
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        ItemPointer dead_tuples;        /* array of ItemPointerData */
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        int                     num_index_scans;
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        bool            scanned_all;    /* have we scanned all pages (this far)? */
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} LVRelStats;
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        vacrelstats = (LVRelStats *) palloc0(sizeof(LVRelStats));
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        vacrelstats->scanned_all = true;        /* will be cleared if we skip a page */
 
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        vacrelstats->old_rel_tuples = onerel->rd_rel->reltuples;
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        vacrelstats->num_index_scans = 0;
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        vacrelstats->scanned_all = true; /* will be cleared if we skip a page */
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        /* Open all indexes of the relation */
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        vac_open_indexes(onerel, RowExclusiveLock, &nindexes, &Irel);
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        vacrelstats->hasindex = (nindexes > 0);
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        /* Do the vacuuming */
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        lazy_scan_heap(onerel, vacrelstats, Irel, nindexes, scan_all);
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         * Update statistics in pg_class.  But only if we didn't skip any pages;
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         * the tuple count only includes tuples from the pages we've visited, and
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         * we haven't frozen tuples in unvisited pages either.  The page count is
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         * accurate in any case, but because we use the reltuples / relpages
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         * ratio in the planner, it's better to not update relpages either if we
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         * can't update reltuples.
 
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         * accurate in any case, but because we use the reltuples / relpages ratio
 
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         * in the planner, it's better to not update relpages either if we can't
 
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         * update reltuples.
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         */
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        if (vacrelstats->scanned_all)
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                vac_update_relstats(onerel,
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        int                     i;
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        PGRUsage        ru0;
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        Buffer          vmbuffer = InvalidBuffer;
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        BlockNumber     all_visible_streak;
 
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        BlockNumber all_visible_streak;
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        pg_rusage_init(&ru0);
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                bool            all_visible;
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                /*
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                 * Skip pages that don't require vacuuming according to the
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                 * visibility map. But only if we've seen a streak of at least
 
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                 * Skip pages that don't require vacuuming according to the visibility
 
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                 * map. But only if we've seen a streak of at least
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                 * SKIP_PAGES_THRESHOLD pages marked as clean. Since we're reading
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                 * sequentially, the OS should be doing readahead for us and there's
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                 * no gain in skipping a page now and then. You need a longer run of
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                                                        all_visible = false;
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                                                        break;
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                                                }
 
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                                                /*
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                                                 * The inserter definitely committed. But is it
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                                                 * old enough that everyone sees it as committed?
 
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                                                 * The inserter definitely committed. But is it old
 
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                                                 * enough that everyone sees it as committed?
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                                                 */
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                                                xmin = HeapTupleHeaderGetXmin(tuple.t_data);
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                                                if (!TransactionIdPrecedes(xmin, OldestXmin))
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        ivinfo.index = indrel;
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        ivinfo.vacuum_full = false;
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        ivinfo.analyze_only = false;
 
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        ivinfo.estimated_count = true;
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        ivinfo.message_level = elevel;
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        /* We don't yet know rel_tuples, so pass -1 */
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        ivinfo.num_heap_tuples = -1;
 
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        ivinfo.num_heap_tuples = vacrelstats->old_rel_tuples;
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        ivinfo.strategy = vac_strategy;
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        /* Do bulk deletion */
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        ivinfo.index = indrel;
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        ivinfo.vacuum_full = false;
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        ivinfo.analyze_only = false;
 
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        ivinfo.estimated_count = !vacrelstats->scanned_all;
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        ivinfo.message_level = elevel;
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        ivinfo.num_heap_tuples = vacrelstats->rel_tuples;
 
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        /* use rel_tuples only if we scanned all pages, else fall back */
 
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        ivinfo.num_heap_tuples = vacrelstats->scanned_all ? vacrelstats->rel_tuples : vacrelstats->old_rel_tuples;
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        ivinfo.strategy = vac_strategy;
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        stats = index_vacuum_cleanup(&ivinfo, stats);
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        if (!stats)
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                return;
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        /* now update statistics in pg_class */
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        vac_update_relstats(indrel,
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                                                stats->num_pages, stats->num_index_tuples,
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                                                false, InvalidTransactionId);
 
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        /*
 
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         * Now update statistics in pg_class, but only if the index says the count
 
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         * is accurate.
 
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         */
 
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        if (!stats->estimated_count)
 
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                vac_update_relstats(indrel,
 
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                                                        stats->num_pages, stats->num_index_tuples,
 
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                                                        false, InvalidTransactionId);
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        ereport(elevel,
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                        (errmsg("index \"%s\" now contains %.0f row versions in %u pages",