Don't reset changes_since_analyze after a selective-columns ANALYZE.

If we ANALYZE only selected columns of a table, we should not postpone
auto-analyze because of that; other columns may well still need stats
updates.  As committed, the counter is left alone if a column list is
given, whether or not it includes all analyzable columns of the table.
Per complaint from Tomasz Ostrowski.

It's been like this a long time, so back-patch to all supported branches.

Report: <ef99c1bd-ff60-5f32-2733-c7b504eb960c@ato.waw.pl>

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 0962933da40adaf6697b84bc28b50c343ffdbed6..8be58fcbdac818ba65282dc15aefc30b0dc6f255 100644 (file)
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -616,10 +616,13 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
        /*
         * Report ANALYZE to the stats collector, too.  However, if doing
         * inherited stats we shouldn't report, because the stats collector only
-        * tracks per-table stats.
+        * tracks per-table stats.  Reset the changes_since_analyze counter only
+        * if we analyzed all columns; otherwise, there is still work for
+        * auto-analyze to do.
         */
        if (!inh)
-               pgstat_report_analyze(onerel, totalrows, totaldeadrows);
+               pgstat_report_analyze(onerel, totalrows, totaldeadrows,
+                                                         (vacstmt->va_cols == NIL));
 
        /* If this isn't part of VACUUM ANALYZE, let index AMs do cleanup */
        if (!(vacstmt->options & VACOPT_VACUUM))

diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 4b0966ba83edb54a9dd637a3f13a5a68a4497d44..6838b3e2b1aade0ed91b1b57301583de891fb31d 100644 (file)
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -1329,11 +1329,15 @@ pgstat_report_vacuum(Oid tableoid, bool shared, PgStat_Counter tuples)
  * pgstat_report_analyze() -
  *
  *     Tell the collector about the table we just analyzed.
+ *
+ * Caller must provide new live- and dead-tuples estimates, as well as a
+ * flag indicating whether to reset the changes_since_analyze counter.
  * --------
  */
 void
 pgstat_report_analyze(Relation rel,
-                                         PgStat_Counter livetuples, PgStat_Counter deadtuples)
+                                         PgStat_Counter livetuples, PgStat_Counter deadtuples,
+                                         bool resetcounter)
 {
        PgStat_MsgAnalyze msg;
 
@@ -1370,6 +1374,7 @@ pgstat_report_analyze(Relation rel,
        msg.m_databaseid = rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId;
        msg.m_tableoid = RelationGetRelid(rel);
        msg.m_autovacuum = IsAutoVacuumWorkerProcess();
+       msg.m_resetcounter = resetcounter;
        msg.m_analyzetime = GetCurrentTimestamp();
        msg.m_live_tuples = livetuples;
        msg.m_dead_tuples = deadtuples;
@@ -4842,10 +4847,12 @@ pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len)
        tabentry->n_dead_tuples = msg->m_dead_tuples;
 
        /*
-        * We reset changes_since_analyze to zero, forgetting any changes that
-        * occurred while the ANALYZE was in progress.
+        * If commanded, reset changes_since_analyze to zero.  This forgets any
+        * changes that were committed while the ANALYZE was in progress, but we
+        * have no good way to estimate how many of those there were.
         */
-       tabentry->changes_since_analyze = 0;
+       if (msg->m_resetcounter)
+               tabentry->changes_since_analyze = 0;
 
        if (msg->m_autovacuum)
        {

diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 3dac0220c016ba8af3cea12579bfc42e942dc5cd..6df6f380c4a1ecafab7ecfee6d1482c04b926a68 100644 (file)
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -359,6 +359,7 @@ typedef struct PgStat_MsgAnalyze
        Oid                     m_databaseid;
        Oid                     m_tableoid;
        bool            m_autovacuum;
+       bool            m_resetcounter;
        TimestampTz m_analyzetime;
        PgStat_Counter m_live_tuples;
        PgStat_Counter m_dead_tuples;
@@ -788,7 +789,8 @@ extern void pgstat_report_autovac(Oid dboid);
 extern void pgstat_report_vacuum(Oid tableoid, bool shared,
                                         PgStat_Counter tuples);
 extern void pgstat_report_analyze(Relation rel,
-                                         PgStat_Counter livetuples, PgStat_Counter deadtuples);
+                                         PgStat_Counter livetuples, PgStat_Counter deadtuples,
+                                         bool resetcounter);
 
 extern void pgstat_report_recovery_conflict(int reason);
 extern void pgstat_report_deadlock(void);