Fix caching of foreign-key-checking queries so that when a replan is needed,

we regenerate the SQL query text not merely the plan derived from it.  This
is needed to handle contingencies such as renaming of a table or column
used in an FK.  Pre-8.3, such cases worked despite the lack of replanning
(because the cached plan needn't actually change), so this is a regression.
Per bug #4417 from Benjamin Bihler.

1 files changed, 31 insertions, 1 deletions

diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 443ee57e682..302109f24f2 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.197 2008/07/18 20:26:06 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.198 2008/09/15 23:37:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1368,6 +1368,36 @@ SPI_is_cursor_plan(SPIPlanPtr plan)
 }
 
 /*
+ * SPI_plan_is_valid --- test whether a SPI plan is currently valid
+ * (that is, not marked as being in need of revalidation).
+ *
+ * See notes for CachedPlanIsValid before using this.
+ */
+bool
+SPI_plan_is_valid(SPIPlanPtr plan)
+{
+	Assert(plan->magic == _SPI_PLAN_MAGIC);
+	if (plan->saved)
+	{
+		ListCell   *lc;
+
+		foreach(lc, plan->plancache_list)
+		{
+			CachedPlanSource *plansource = (CachedPlanSource *) lfirst(lc);
+
+			if (!CachedPlanIsValid(plansource))
+				return false;
+		}
+		return true;
+	}
+	else
+	{
+		/* An unsaved plan is assumed valid for its (short) lifetime */
+		return true;
+	}
+}
+
+/*
  * SPI_result_code_string --- convert any SPI return code to a string
  *
  * This is often useful in error messages.	Most callers will probably