Prevent core dump in contrib version of autovacuum when a table has been

dropped.  Per report from daveg (not his patch, though).

diff --git a/contrib/pg_autovacuum/pg_autovacuum.c b/contrib/pg_autovacuum/pg_autovacuum.c
index 3775157d668fe97a14e0ded3691b33bf5dd7996a..d202d1898597e872f54b14458c26d78a2f32ee2f 100644 (file)
--- a/contrib/pg_autovacuum/pg_autovacuum.c
+++ b/contrib/pg_autovacuum/pg_autovacuum.c
@@ -142,7 +142,7 @@ init_table_info(PGresult *res, int row, db_info * dbi)
 void
 update_table_thresholds(db_info * dbi, tbl_info * tbl, int vacuum_type)
 {
-       PGresult   *res = NULL;
+       PGresult   *res;
        int                     disconnect = 0;
        char            query[128];
 
@@ -156,7 +156,7 @@ update_table_thresholds(db_info * dbi, tbl_info * tbl, int vacuum_type)
        {
                snprintf(query, sizeof(query), PAGES_QUERY, tbl->relid);
                res = send_query(query, dbi);
-               if (res != NULL)
+               if (res != NULL && PQntuples(res) > 0)
                {
                        tbl->reltuples =
                                atof(PQgetvalue(res, 0, PQfnumber(res, "reltuples")));
@@ -178,8 +178,6 @@ update_table_thresholds(db_info * dbi, tbl_info * tbl, int vacuum_type)
                                (args->analyze_base_threshold + args->analyze_scaling_factor * tbl->reltuples);
                        tbl->CountAtLastAnalyze = tbl->curr_analyze_count;
 
-                       PQclear(res);
-
                        /*
                         * If the stats collector is reporting fewer updates then we
                         * have on record then the stats were probably reset, so we
@@ -192,6 +190,8 @@ update_table_thresholds(db_info * dbi, tbl_info * tbl, int vacuum_type)
                                tbl->CountAtLastVacuum = tbl->curr_vacuum_count;
                        }
                }
+
+               PQclear(res);
        }
        if (disconnect)
                db_disconnect(dbi);