From 30d572fac2aa58ce2d62ba929c30fded9b020e0b Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Thu, 2 May 2024 08:16:33 +0900
Subject: [PATCH v2 1/4] Refactor some code of ALTER TABLE SET LOGGED/UNLOGGED

This is in preparation for an upcoming patch set to extend the
possibilities in this area, making the code more consistent with the
surroundings related to access methods and tablespaces.
---
 src/backend/commands/tablecmds.c | 38 +++++++++++++-------------------
 1 file changed, 15 insertions(+), 23 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 08c87e6029..baabbf82e7 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -602,7 +602,8 @@ static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName,
 static void ATExecDropCluster(Relation rel, LOCKMODE lockmode);
 static void ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname);
 static void ATExecSetAccessMethodNoStorage(Relation rel, Oid newAccessMethod);
-static bool ATPrepChangePersistence(Relation rel, bool toLogged);
+static void ATPrepSetPersistence(AlteredTableInfo *tab, Relation rel,
+								 bool toLogged);
 static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel,
 								const char *tablespacename, LOCKMODE lockmode);
 static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode);
@@ -5037,13 +5038,7 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 				ereport(ERROR,
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 						 errmsg("cannot change persistence setting twice")));
-			tab->chgPersistence = ATPrepChangePersistence(rel, true);
-			/* force rewrite if necessary; see comment in ATRewriteTables */
-			if (tab->chgPersistence)
-			{
-				tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
-				tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
-			}
+			ATPrepSetPersistence(tab, rel, true);
 			pass = AT_PASS_MISC;
 			break;
 		case AT_SetUnLogged:	/* SET UNLOGGED */
@@ -5052,13 +5047,7 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 				ereport(ERROR,
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 						 errmsg("cannot change persistence setting twice")));
-			tab->chgPersistence = ATPrepChangePersistence(rel, false);
-			/* force rewrite if necessary; see comment in ATRewriteTables */
-			if (tab->chgPersistence)
-			{
-				tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
-				tab->newrelpersistence = RELPERSISTENCE_UNLOGGED;
-			}
+			ATPrepSetPersistence(tab, rel, false);
 			pass = AT_PASS_MISC;
 			break;
 		case AT_DropOids:		/* SET WITHOUT OIDS */
@@ -17775,12 +17764,9 @@ ATExecSetCompression(Relation rel,
  * This verifies that we're not trying to change a temp table.  Also,
  * existing foreign key constraints are checked to avoid ending up with
  * permanent tables referencing unlogged tables.
- *
- * Return value is false if the operation is a no-op (in which case the
- * checks are skipped), otherwise true.
  */
-static bool
-ATPrepChangePersistence(Relation rel, bool toLogged)
+static void
+ATPrepSetPersistence(AlteredTableInfo *tab, Relation rel, bool toLogged)
 {
 	Relation	pg_constraint;
 	HeapTuple	tuple;
@@ -17804,12 +17790,12 @@ ATPrepChangePersistence(Relation rel, bool toLogged)
 		case RELPERSISTENCE_PERMANENT:
 			if (toLogged)
 				/* nothing to do */
-				return false;
+				return;
 			break;
 		case RELPERSISTENCE_UNLOGGED:
 			if (!toLogged)
 				/* nothing to do */
-				return false;
+				return;
 			break;
 	}
 
@@ -17892,7 +17878,13 @@ ATPrepChangePersistence(Relation rel, bool toLogged)
 
 	table_close(pg_constraint, AccessShareLock);
 
-	return true;
+	/* force rewrite if necessary; see comment in ATRewriteTables */
+	tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
+	if (toLogged)
+		tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
+	else
+		tab->newrelpersistence = RELPERSISTENCE_UNLOGGED;
+	tab->chgPersistence = true;
 }
 
 /*
-- 
2.43.0