Function InitCatalogCache

src/backend/utils/cache/syscache.c:1249–1300

* InitCatalogCache - initialize the caches * * Note that no database access is done here; we only allocate memory * and initialize the cache structure. Interrogation of the database * to complete initialization of a cache happens upon first use * of that cache. */

 * of that cache.
 */
void
InitCatalogCache(void)
{
	int			cacheId;

	StaticAssertStmt(SysCacheSize == (int) lengthof(cacheinfo),
					 "SysCacheSize does not match syscache.c's array");

	Assert(!CacheInitialized);

	SysCacheRelationOidSize = SysCacheSupportingRelOidSize = 0;

	for (cacheId = 0; cacheId < SysCacheSize; cacheId++)
	{
		SysCache[cacheId] = InitCatCache(cacheId,
										 cacheinfo[cacheId].reloid,
										 cacheinfo[cacheId].indoid,
										 cacheinfo[cacheId].nkeys,
										 cacheinfo[cacheId].key,
										 cacheinfo[cacheId].nbuckets);
		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));
	}

	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);
	SysCacheRelationOidSize =
		qunique(SysCacheRelationOid, SysCacheRelationOidSize, sizeof(Oid),
				oid_compare);

	pg_qsort(SysCacheSupportingRelOid, SysCacheSupportingRelOidSize,
			 sizeof(Oid), oid_compare);
	SysCacheSupportingRelOidSize =
		qunique(SysCacheSupportingRelOid, SysCacheSupportingRelOidSize,
				sizeof(Oid), oid_compare);

	CacheInitialized = true;
}

/*
 * InitCatalogCachePhase2 - finish initializing the caches