Fix REFRESH MATERIALIZED VIEW to report activity to the stats collector.

The non-concurrent code path for REFRESH MATERIALIZED VIEW failed to
report its updates to the stats collector.  This is bad since it means
auto-analyze doesn't know there's any work to be done.  Adjust it to
report the refresh as a table truncate followed by insertion of an
appropriate number of rows.

Since a matview could contain more than INT_MAX rows, change the
signature of pgstat_count_heap_insert() to accept an int64 rowcount.
(The accumulator it's adding into is already int64, but existing
callers could not insert more than a small number of rows at once,
so the argument had been declared just "int n".)

This is surely a bug fix, but changing pgstat_count_heap_insert()'s API
seems too risky for the back branches.  Given the lack of previous
complaints, I'm not sure it's a big enough problem to justify a kluge
solution that would avoid that.  So, no back-patch, at least for now.

Jim Mlodgenski, adjusted a bit by me

Discussion: https://postgr.es/m/CAB_5SRchSz7-WmdO5szdiknG8Oj_GGqJytrk1KRd11yhcMs1KQ@mail.gmail.com

diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index a18c9173360d5adf322d82102ba8b27f64b118f1..c952dea6ead81ca6986d340072253932d6a35900 100644 (file)
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -30,6 +30,7 @@
 #include "executor/spi.h"
 #include "miscadmin.h"
 #include "parser/parse_relation.h"
+#include "pgstat.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
 #include "storage/smgr.h"
@@ -59,7 +60,7 @@ static void transientrel_startup(DestReceiver *self, int operation, TupleDesc ty
 static bool transientrel_receive(TupleTableSlot *slot, DestReceiver *self);
 static void transientrel_shutdown(DestReceiver *self);
 static void transientrel_destroy(DestReceiver *self);
-static void refresh_matview_datafill(DestReceiver *dest, Query *query,
+static uint64 refresh_matview_datafill(DestReceiver *dest, Query *query,
                         const char *queryString);
 
 static char *make_temptable_name_n(char *tempname, int n);
@@ -145,6 +146,7 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
    Oid         relowner;
    Oid         OIDNewHeap;
    DestReceiver *dest;
+   uint64      processed = 0;
    bool        concurrent;
    LOCKMODE    lockmode;
    char        relpersistence;
@@ -322,7 +324,7 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
 
    /* Generate the data, if wanted. */
    if (!stmt->skipData)
-       refresh_matview_datafill(dest, dataQuery, queryString);
+       processed = refresh_matview_datafill(dest, dataQuery, queryString);
 
    heap_close(matviewRel, NoLock);
 
@@ -345,8 +347,20 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
        Assert(matview_maintenance_depth == old_depth);
    }
    else
+   {
        refresh_by_heap_swap(matviewOid, OIDNewHeap, relpersistence);
 
+       /*
+        * Inform stats collector about our activity: basically, we truncated
+        * the matview and inserted some new data.  (The concurrent code path
+        * above doesn't need to worry about this because the inserts and
+        * deletes it issues get counted by lower-level code.)
+        */
+       pgstat_count_truncate(matviewRel);
+       if (!stmt->skipData)
+           pgstat_count_heap_insert(matviewRel, processed);
+   }
+
    /* Roll back any GUC changes */
    AtEOXact_GUC(false, save_nestlevel);
 
@@ -360,8 +374,13 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
 
 /*
  * refresh_matview_datafill
+ *
+ * Execute the given query, sending result rows to "dest" (which will
+ * insert them into the target matview).
+ *
+ * Returns number of rows inserted.
  */
-static void
+static uint64
 refresh_matview_datafill(DestReceiver *dest, Query *query,
                         const char *queryString)
 {
@@ -369,6 +388,7 @@ refresh_matview_datafill(DestReceiver *dest, Query *query,
    PlannedStmt *plan;
    QueryDesc  *queryDesc;
    Query      *copied_query;
+   uint64      processed;
 
    /* Lock and rewrite, using a copy to preserve the original query. */
    copied_query = copyObject(query);
@@ -406,6 +426,8 @@ refresh_matview_datafill(DestReceiver *dest, Query *query,
    /* run the plan */
    ExecutorRun(queryDesc, ForwardScanDirection, 0L);
 
+   processed = queryDesc->estate->es_processed;
+
    /* and clean up */
    ExecutorFinish(queryDesc);
    ExecutorEnd(queryDesc);
@@ -413,6 +435,8 @@ refresh_matview_datafill(DestReceiver *dest, Query *query,
    FreeQueryDesc(queryDesc);
 
    PopActiveSnapshot();
+
+   return processed;
 }
 
 DestReceiver *

diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 5fe9f35199ae8296dd8d425f3e5327d2841e7dbe..3a50488db3286036583d9fed2d18ea956cad4cdd 100644 (file)
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -1803,7 +1803,7 @@ add_tabstat_xact_level(PgStat_TableStatus *pgstat_info, int nest_level)
  * pgstat_count_heap_insert - count a tuple insertion of n tuples
  */
 void
-pgstat_count_heap_insert(Relation rel, int n)
+pgstat_count_heap_insert(Relation rel, PgStat_Counter n)
 {
    PgStat_TableStatus *pgstat_info = rel->pgstat_info;
 

diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9d2e1fe19f43b6f95237a605011d26c12153c100..f2daf32e1abaa868cd9d7cec18fdfc1f14efe8b7 100644 (file)
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -1256,7 +1256,7 @@ pgstat_report_wait_end(void)
 #define pgstat_count_buffer_write_time(n)                          \
    (pgStatBlockWriteTime += (n))
 
-extern void pgstat_count_heap_insert(Relation rel, int n);
+extern void pgstat_count_heap_insert(Relation rel, PgStat_Counter n);
 extern void pgstat_count_heap_update(Relation rel, bool hot);
 extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);