1 files changed, 61 insertions, 11 deletions

diff --git a/src/backend/utils/cache/syscache.c b/src/backend/utils/cache/syscache.c
index 94d951ce056..81cde1295f3 100644
--- a/src/backend/utils/cache/syscache.c
+++ b/src/backend/utils/cache/syscache.c
@@ -798,17 +798,23 @@ static const struct cachedesc cacheinfo[] = {
 	}
 };
 
-static CatCache *SysCache[
-						  lengthof(cacheinfo)];
-static int	SysCacheSize = lengthof(cacheinfo);
+#define SysCacheSize	((int) lengthof(cacheinfo))
+
+static CatCache *SysCache[SysCacheSize];
+
 static bool CacheInitialized = false;
 
-static Oid	SysCacheRelationOid[
-								lengthof(cacheinfo)];
+/* Sorted array of OIDs of tables that have caches on them */
+static Oid	SysCacheRelationOid[SysCacheSize];
 static int	SysCacheRelationOidSize;
 
+/* Sorted array of OIDs of tables and indexes used by caches */
+static Oid	SysCacheSupportingRelOid[SysCacheSize * 2];
+static int	SysCacheSupportingRelOidSize;
+
 static int	oid_compare(const void *a, const void *b);
 
+
 /*
  * InitCatalogCache - initialize the caches
  *
@@ -822,11 +828,11 @@ InitCatalogCache(void)
 {
 	int			cacheId;
 	int			i,
-				j = 0;
+				j;
 
 	Assert(!CacheInitialized);
 
-	MemSet(SysCache, 0, sizeof(SysCache));
+	SysCacheRelationOidSize = SysCacheSupportingRelOidSize = 0;
 
 	for (cacheId = 0; cacheId < SysCacheSize; cacheId++)
 	{
@@ -839,20 +845,39 @@ InitCatalogCache(void)
 		if (!PointerIsValid(SysCache[cacheId]))
 			elog(ERROR, "could not initialize cache %u (%d)",
 				 cacheinfo[cacheId].reloid, cacheId);
+		/* Accumulate data for OID lists, too */
 		SysCacheRelationOid[SysCacheRelationOidSize++] =
 			cacheinfo[cacheId].reloid;
+		SysCacheSupportingRelOid[SysCacheSupportingRelOidSize++] =
+			cacheinfo[cacheId].reloid;
+		SysCacheSupportingRelOid[SysCacheSupportingRelOidSize++] =
+			cacheinfo[cacheId].indoid;
 		/* see comments for RelationInvalidatesSnapshotsOnly */
 		Assert(!RelationInvalidatesSnapshotsOnly(cacheinfo[cacheId].reloid));
 	}
 
-	/* Sort and dedup OIDs. */
+	Assert(SysCacheRelationOidSize <= lengthof(SysCacheRelationOid));
+	Assert(SysCacheSupportingRelOidSize <= lengthof(SysCacheSupportingRelOid));
+
+	/* Sort and de-dup OID arrays, so we can use binary search. */
 	pg_qsort(SysCacheRelationOid, SysCacheRelationOidSize,
 			 sizeof(Oid), oid_compare);
-	for (i = 1; i < SysCacheRelationOidSize; ++i)
+	for (i = 1, j = 0; i < SysCacheRelationOidSize; i++)
+	{
 		if (SysCacheRelationOid[i] != SysCacheRelationOid[j])
 			SysCacheRelationOid[++j] = SysCacheRelationOid[i];
+	}
 	SysCacheRelationOidSize = j + 1;
 
+	pg_qsort(SysCacheSupportingRelOid, SysCacheSupportingRelOidSize,
+			 sizeof(Oid), oid_compare);
+	for (i = 1, j = 0; i < SysCacheSupportingRelOidSize; i++)
+	{
+		if (SysCacheSupportingRelOid[i] != SysCacheSupportingRelOid[j])
+			SysCacheSupportingRelOid[++j] = SysCacheSupportingRelOid[i];
+	}
+	SysCacheSupportingRelOidSize = j + 1;
+
 	CacheInitialized = true;
 }
 
@@ -1195,6 +1220,31 @@ RelationHasSysCache(Oid relid)
 	return false;
 }
 
+/*
+ * Test whether a relation supports a system cache, ie it is either a
+ * cached table or the index used for a cache.
+ */
+bool
+RelationSupportsSysCache(Oid relid)
+{
+	int			low = 0,
+				high = SysCacheSupportingRelOidSize - 1;
+
+	while (low <= high)
+	{
+		int			middle = low + (high - low) / 2;
+
+		if (SysCacheSupportingRelOid[middle] == relid)
+			return true;
+		if (SysCacheSupportingRelOid[middle] < relid)
+			low = middle + 1;
+		else
+			high = middle - 1;
+	}
+
+	return false;
+}
+
 
 /*
  * OID comparator for pg_qsort
@@ -1202,8 +1252,8 @@ RelationHasSysCache(Oid relid)
 static int
 oid_compare(const void *a, const void *b)
 {
-	Oid			oa = *((Oid *) a);
-	Oid			ob = *((Oid *) b);
+	Oid			oa = *((const Oid *) a);
+	Oid			ob = *((const Oid *) b);
 
 	if (oa == ob)
 		return 0;