/*
* InitCatalogCachePhase2 - finish initializing the caches
*
* Finish initializing all the caches, including necessary database
* access.
*
* This is *not* essential; normally we allow syscaches to be initialized
* on first use. However, it is useful as a mechanism to preload the
* relcache with entries for the most-commonly-used system catalogs.
* Therefore, we invoke this routine when we need to write a new relcache
* init file.
*/
void
InitCatalogCachePhase2(void)
{
int cacheId;
Assert(CacheInitialized);
for (cacheId = 0; cacheId < SysCacheSize; cacheId++)
{
/*
* In order for upgrade to work successfully we must be able to run
* in single user mode with a catalog like the GP 3.2 catalog. To
* support this we must skip the optional syscache initialization
* for catalog tables that did not exist in 3.2, otherwise we will
* try to read the relation before we have created it and will fail
* to startup.
*/
if ((IsBootstrapProcessingMode() || IsInitProcessingMode()) &&
((cacheinfo[cacheId].reloid == ForeignDataWrapperRelationId) ||
(cacheinfo[cacheId].reloid == ForeignServerRelationId) ||
(cacheinfo[cacheId].reloid == UserMappingRelationId)))
{
continue;
}
InitCatCachePhase2(SysCache[cacheId], true);
}
}
/*
* InitCatalogCachePhase2 - finish initializing the caches
*
* Finish initializing all the caches, including necessary database
* access.
*
* This is *not* essential; normally we allow syscaches to be initialized
* on first use. However, it is useful as a mechanism to preload the
* relcache with entries for the most-commonly-used system catalogs.
* Therefore, we invoke this routine when we need to write a new relcache
* init file.
*/
void
InitCatalogCachePhase2(void)
{
int cacheId;
Assert(CacheInitialized);
for (cacheId = 0; cacheId < SysCacheSize; cacheId++)
InitCatCachePhase2(SysCache[cacheId], true);
}
/*
* SysCacheGetAttr
*
* Given a tuple previously fetched by SearchSysCache(),
* extract a specific attribute.
*
* This is equivalent to using heap_getattr() on a tuple fetched
* from a non-cached relation. Usually, this is only used for attributes
* that could be NULL or variable length; the fixed-size attributes in
* a system table are accessed just by mapping the tuple onto the C struct
* declarations from include/catalog/.
*
* As with heap_getattr(), if the attribute is of a pass-by-reference type
* then a pointer into the tuple data area is returned --- the caller must
* not modify or pfree the datum!
*
* Note: it is legal to use SysCacheGetAttr() with a cacheId referencing
* a different cache for the same catalog the tuple was fetched from.
*/
Datum
SysCacheGetAttr(int cacheId, HeapTuple tup,
AttrNumber attributeNumber,
bool *isNull)
{
/*
* We just need to get the TupleDesc out of the cache entry, and then we
* can apply heap_getattr(). Normally the cache control data is already
* valid (because the caller recently fetched the tuple via this same
* cache), but there are cases where we have to initialize the cache here.
*/
if (cacheId < 0 || cacheId >= SysCacheSize ||
!PointerIsValid(SysCache[cacheId]))
elog(ERROR, "invalid cache id: %d", cacheId);
if (!PointerIsValid(SysCache[cacheId]->cc_tupdesc))
{
InitCatCachePhase2(SysCache[cacheId], false);
Assert(PointerIsValid(SysCache[cacheId]->cc_tupdesc));
}
return heap_getattr(tup, attributeNumber,
SysCache[cacheId]->cc_tupdesc,
isNull);
}
