Remove dead foreign key optimization code

petere · petere · commit 34479d9a36a2 · 2018-11-10T16:14:51.000+01:00
The ri_KeysEqual() calls in the foreign-key trigger functions to optimize away some updates are useless because since adfeef5 those triggers are not enqueued at all. (It's also not useful to keep these checks as some kind of backstop, since it's also semantically correct to just run the full check even with equal keys.) Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
@@ -744,20 +744,6 @@ ri_restrict(TriggerData *trigdata, bool is_no_action)
 					break;
 			}
 
-			/*
-			 * In UPDATE, no need to do anything if old and new keys are equal
-			 */
-			if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
-			{
-				HeapTuple	new_row = trigdata->tg_newtuple;
-
-				if (ri_KeysEqual(pk_rel, old_row, new_row, riinfo, true))
-				{
-					heap_close(fk_rel, RowShareLock);
-					return PointerGetDatum(NULL);
-				}
-			}
-
 			/*
 			 * If another PK row now exists providing the old key values, we
 			 * should not do anything.  However, this check should only be
@@ -1098,15 +1084,6 @@ RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
 					break;
 			}
 
-			/*
-			 * No need to do anything if old and new keys are equal
-			 */
-			if (ri_KeysEqual(pk_rel, old_row, new_row, riinfo, true))
-			{
-				heap_close(fk_rel, RowExclusiveLock);
-				return PointerGetDatum(NULL);
-			}
-
 			if (SPI_connect() != SPI_OK_CONNECT)
 				elog(ERROR, "SPI_connect failed");
 
@@ -1316,20 +1293,6 @@ ri_setnull(TriggerData *trigdata)
 					break;
 			}
 
-			/*
-			 * In UPDATE, no need to do anything if old and new keys are equal
-			 */
-			if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
-			{
-				HeapTuple	new_row = trigdata->tg_newtuple;
-
-				if (ri_KeysEqual(pk_rel, old_row, new_row, riinfo, true))
-				{
-					heap_close(fk_rel, RowExclusiveLock);
-					return PointerGetDatum(NULL);
-				}
-			}
-
 			if (SPI_connect() != SPI_OK_CONNECT)
 				elog(ERROR, "SPI_connect failed");
 
@@ -1536,20 +1499,6 @@ ri_setdefault(TriggerData *trigdata)
 					break;
 			}
 
-			/*
-			 * In UPDATE, no need to do anything if old and new keys are equal
-			 */
-			if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
-			{
-				HeapTuple	new_row = trigdata->tg_newtuple;
-
-				if (ri_KeysEqual(pk_rel, old_row, new_row, riinfo, true))
-				{
-					heap_close(fk_rel, RowExclusiveLock);
-					return PointerGetDatum(NULL);
-				}
-			}
-
 			if (SPI_connect() != SPI_OK_CONNECT)
 				elog(ERROR, "SPI_connect failed");
 
