database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-03 20:02:46 +03:00
Code Activity

Improve tuplestore.c to support multiple concurrent read positions.

Browse Source 
This facility replaces the former mark/restore support but is otherwise
upward-compatible with previous uses.  It's expected to be needed for
single evaluation of CTEs and also for window functions, so I'm committing
it separately instead of waiting for either one of those patches to be
finished.  Per discussion with Greg Stark and Hitoshi Harada.

Note: I removed nodeFunctionscan's mark/restore support, instead of bothering
to update it for this change, because it was dead code anyway.
This commit is contained in:
Tom Lane
2008-10-01 19:51:50 +00:00
parent 233f135144
commit dad4cb6258
7 changed files with 382 additions and 236 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
src/backend/executor/nodeFunctionscan.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/executor/nodeFunctionscan.c,v 1.46 2008/02/29 02:49:39 neilc Exp $
* $PostgreSQL: pgsql/src/backend/executor/nodeFunctionscan.c,v 1.47 2008/10/01 19:51:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -131,6 +131,9 @@ ExecInitFunctionScan(FunctionScan *node, EState *estate, int eflags)
TypeFuncClass functypclass;
TupleDesc tupdesc = NULL;
/* check for unsupported flags */
Assert(!(eflags & EXEC_FLAG_MARK));
/*
* FunctionScan should not have any children.
*/
@ -273,42 +276,6 @@ ExecEndFunctionScan(FunctionScanState *node)
node->tuplestorestate = NULL;
}
/* ----------------------------------------------------------------
* ExecFunctionMarkPos
*
* Calls tuplestore to save the current position in the stored file.
* ----------------------------------------------------------------
*/
void
ExecFunctionMarkPos(FunctionScanState *node)
{
/*
* if we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
tuplestore_markpos(node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecFunctionRestrPos
*
* Calls tuplestore to restore the last saved file position.
* ----------------------------------------------------------------
*/
void
ExecFunctionRestrPos(FunctionScanState *node)
{
/*
* if we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
tuplestore_restorepos(node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecFunctionReScan
*