Small refactoring around ExecCreateTableAs().

Since commit 4b74ebf726, the refresh logic is used to populate
materialized views, so we can simplify the error message in
ExecCreateTableAs().

Also, RefreshMatViewByOid() is moved to just after
create_ctas_nodata() call to improve code readability.

Author: Yugo Nagata
Discussion: https://postgr.es/m/20240802161301.d975daca9ba7a706fa05ecd7@sraoss.co.jp

diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 36e192b79b25289f1bb71a4b7a703b2794545218..c71ff80188878ddae18a12dbdc5e85aacbf41e89 100644 (file)
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -228,9 +228,6 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
        bool            do_refresh = false;
        DestReceiver *dest;
        ObjectAddress address;
-       List       *rewritten;
-       PlannedStmt *plan;
-       QueryDesc  *queryDesc;
 
        /* Check if the relation exists or not */
        if (CreateTableAsRelExists(stmt))
@@ -279,9 +276,25 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
                 * from running the planner before all dependencies are set up.
                 */
                address = create_ctas_nodata(query->targetList, into);
+
+               /*
+                * For materialized views, reuse the REFRESH logic, which locks down
+                * security-restricted operations and restricts the search_path.  This
+                * reduces the chance that a subsequent refresh will fail.
+                */
+               if (do_refresh)
+                       RefreshMatViewByOid(address.objectId, true, false, false,
+                                                               pstate->p_sourcetext, qc);
+
        }
        else
        {
+               List       *rewritten;
+               PlannedStmt *plan;
+               QueryDesc  *queryDesc;
+
+               Assert(!is_matview);
+
                /*
                 * Parse analysis was done already, but we still have to run the rule
                 * rewriter.  We do not do AcquireRewriteLocks: we assume the query
@@ -292,9 +305,7 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
 
                /* SELECT should never rewrite to more or less than one SELECT query */
                if (list_length(rewritten) != 1)
-                       elog(ERROR, "unexpected rewrite result for %s",
-                                is_matview ? "CREATE MATERIALIZED VIEW" :
-                                "CREATE TABLE AS SELECT");
+                       elog(ERROR, "unexpected rewrite result for CREATE TABLE AS SELECT");
                query = linitial_node(Query, rewritten);
                Assert(query->commandType == CMD_SELECT);
 
@@ -339,17 +350,6 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
                PopActiveSnapshot();
        }
 
-       /*
-        * For materialized views, reuse the REFRESH logic, which locks down
-        * security-restricted operations and restricts the search_path.  This
-        * reduces the chance that a subsequent refresh will fail.
-        */
-       if (do_refresh)
-       {
-               RefreshMatViewByOid(address.objectId, true, false, false,
-                                                       pstate->p_sourcetext, qc);
-       }
-
        return address;
 }