Function ExecHashTableDestroy

src/backend/executor/nodeHash.c:1085–1125

---------------------------------------------------------------- * ExecHashTableDestroy * * destroy a hash table * ---------------------------------------------------------------- */

 * ----------------------------------------------------------------
 */
void
ExecHashTableDestroy(HashState *hashState, HashJoinTable hashtable)
{
	int			i;

	Assert(hashtable);
	Assert(!hashtable->eagerlyReleased);

	/*
	 * Make sure all the temp files are closed.
	 * GPDB supports rescan of hashjoin, the batch0 can still have temp files.
	 */
	if (hashtable->innerBatchFile != NULL)
	{
		for (i = 0; i < hashtable->nbatch; i++)
		{
			if (hashtable->innerBatchFile[i])
				BufFileClose(hashtable->innerBatchFile[i]);
			if (hashtable->outerBatchFile[i])
				BufFileClose(hashtable->outerBatchFile[i]);
			hashtable->innerBatchFile[i] = NULL;
			hashtable->outerBatchFile[i] = NULL;
		}
	}

	if (hashtable->work_set != NULL)
	{
		workfile_mgr_close_set(hashtable->work_set);
		hashtable->work_set = NULL;
	}

	/* Release working memory (batchCxt is a child, so it goes away too) */
	MemoryContextDelete(hashtable->hashCxt);

	/*
	 * If HashJoin find that the tuple it will return is NULL, it may squelch itself and its children.
	 * But there are some statistics(e.g. nbuckets, nbatch) maintained by the hash table being required during an explain analyze.
	 * Squelch HashJoin will call this function so that we can't simply call pfree and set hash table to NULL here,
	 * otherwise the statistics will be lost.
	 */
}

/*
 * ExecHashIncreaseNumBatches