示例#1
0
/*
 * tuplestore_begin_heap
 *
 * Create a new tuplestore; other types of tuple stores (other than
 * "heap" tuple stores, for heap tuples) are possible, but not presently
 * implemented.
 *
 * randomAccess: if true, both forward and backward accesses to the
 * tuple store are allowed.
 *
 * interXact: if true, the files used for on-disk storage persist beyond the
 * end of the current transaction.	NOTE: It's the caller's responsibility to
 * create such a tuplestore in a memory context that will also survive
 * transaction boundaries, and to ensure the tuplestore is closed when it's
 * no longer wanted.
 *
 * maxKBytes: how much data to store in memory (any data beyond this
 * amount is paged to disk).  When in doubt, use work_mem.
 */
Tuplestorestate *
tuplestore_begin_heap(bool randomAccess, bool interXact, int maxKBytes)
{
	Tuplestorestate *state;

	state = tuplestore_begin_common(randomAccess, interXact, maxKBytes); 

	state->copytup = copytup_heap;
	state->writetup = writetup_heap;
	state->readtup = readtup_heap;

	return state;
}
示例#2
0
Tuplestorestate *
tuplestore_begin_heap_file_readerwriter(const char* fileName, bool isWriter)
{
	Tuplestorestate *state;
	
	state = tuplestore_begin_common(true, true, 1); 
	
	state->myfile = BufFileCreateTemp_ReaderWriter(fileName, isWriter); 
	state->status = isWriter ? TSS_WRITEFILE : TSS_READFILE;

	state->copytup = copytup_heap;
	state->writetup = writetup_heap;
	state->readtup = readtup_heap;

	return state;
}
示例#3
0
/*
 * tuplestore_begin_heap
 *
 * Create a new tuplestore; other types of tuple stores (other than
 * "heap" tuple stores, for heap tuples) are possible, but not presently
 * implemented.
 *
 * randomAccess: if true, both forward and backward accesses to the
 * tuple store are allowed.
 *
 * interXact: if true, the files used for on-disk storage persist beyond the
 * end of the current transaction.  NOTE: It's the caller's responsibility to
 * create such a tuplestore in a memory context and resource owner that will
 * also survive transaction boundaries, and to ensure the tuplestore is closed
 * when it's no longer wanted.
 *
 * maxKBytes: how much data to store in memory (any data beyond this
 * amount is paged to disk).  When in doubt, use work_mem.
 */
Tuplestorestate *
tuplestore_begin_heap(bool randomAccess, bool interXact, int maxKBytes)
{
	Tuplestorestate *state;
	int			eflags;

	/*
	 * This interpretation of the meaning of randomAccess is compatible with
	 * the pre-8.3 behavior of tuplestores.
	 */
	eflags = randomAccess ?
		(EXEC_FLAG_BACKWARD | EXEC_FLAG_REWIND) :
		(EXEC_FLAG_REWIND);

	state = tuplestore_begin_common(eflags, interXact, maxKBytes);

	state->copytup = copytup_heap;
	state->writetup = writetup_heap;
	state->readtup = readtup_heap;

	return state;
}