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-rw-r--r--src/backend/executor/execAmi.c60
-rw-r--r--src/backend/executor/execMain.c6
-rw-r--r--src/backend/executor/spi.c104
3 files changed, 72 insertions, 98 deletions
diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c
index b22ad763498..b189e3e94bc 100644
--- a/src/backend/executor/execAmi.c
+++ b/src/backend/executor/execAmi.c
@@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Header: /cvsroot/pgsql/src/backend/executor/execAmi.c,v 1.69 2003/02/09 00:30:39 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/execAmi.c,v 1.70 2003/03/10 03:53:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -281,3 +281,61 @@ ExecSupportsMarkRestore(NodeTag plantype)
return false;
}
+
+/*
+ * ExecSupportsBackwardScan - does a plan type support backwards scanning?
+ *
+ * Ideally, all plan types would support backwards scan, but that seems
+ * unlikely to happen soon. In some cases, a plan node passes the backwards
+ * scan down to its children, and so supports backwards scan only if its
+ * children do. Therefore, this routine must be passed a complete plan tree.
+ */
+bool
+ExecSupportsBackwardScan(Plan *node)
+{
+ if (node == NULL)
+ return false;
+
+ switch (nodeTag(node))
+ {
+ case T_Result:
+ if (outerPlan(node) != NULL)
+ return ExecSupportsBackwardScan(outerPlan(node));
+ else
+ return false;
+
+ case T_Append:
+ {
+ List *l;
+
+ foreach(l, ((Append *) node)->appendplans)
+ {
+ if (!ExecSupportsBackwardScan((Plan *) lfirst(l)))
+ return false;
+ }
+ return true;
+ }
+
+ case T_SeqScan:
+ case T_IndexScan:
+ case T_TidScan:
+ case T_FunctionScan:
+ return true;
+
+ case T_SubqueryScan:
+ return ExecSupportsBackwardScan(((SubqueryScan *) node)->subplan);
+
+ case T_Material:
+ case T_Sort:
+ return true;
+
+ case T_Unique:
+ return ExecSupportsBackwardScan(outerPlan(node));
+
+ case T_Limit:
+ return ExecSupportsBackwardScan(outerPlan(node));
+
+ default:
+ return false;
+ }
+}
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 9c4b6e74819..f037e72fd91 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -26,7 +26,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.200 2003/02/03 15:07:06 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.201 2003/03/10 03:53:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -537,9 +537,7 @@ InitPlan(QueryDesc *queryDesc)
*/
do_select_into = false;
- if (operation == CMD_SELECT &&
- !parseTree->isPortal &&
- parseTree->into != NULL)
+ if (operation == CMD_SELECT && parseTree->into != NULL)
{
do_select_into = true;
/*
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index d94e12cde56..e1ccdf08f97 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.86 2003/02/14 21:12:45 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.87 2003/03/10 03:53:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -725,9 +725,7 @@ SPI_cursor_open(const char *name, void *plan, Datum *Values, const char *Nulls)
if (queryTree->commandType != CMD_SELECT)
elog(ERROR, "plan in SPI_cursor_open() is not a SELECT");
- if (queryTree->isPortal)
- elog(ERROR, "plan in SPI_cursor_open() must NOT be a DECLARE already");
- else if (queryTree->into != NULL)
+ if (queryTree->into != NULL)
elog(ERROR, "plan in SPI_cursor_open() must NOT be a SELECT INTO");
/* Increment CommandCounter to see changes made by now */
@@ -764,20 +762,12 @@ SPI_cursor_open(const char *name, void *plan, Datum *Values, const char *Nulls)
/* Create the portal */
portal = CreatePortal(name);
- if (portal == NULL)
- elog(ERROR, "failed to create portal \"%s\"", name);
/* Switch to portals memory and copy the parsetree and plan to there */
oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
queryTree = copyObject(queryTree);
planTree = copyObject(planTree);
- /* Modify the parsetree to be a cursor */
- queryTree->isPortal = true;
- queryTree->into = makeNode(RangeVar);
- queryTree->into->relname = pstrdup(name);
- queryTree->isBinary = false;
-
/* If the plan has parameters, set them up */
if (spiplan->nargs > 0)
{
@@ -812,7 +802,7 @@ SPI_cursor_open(const char *name, void *plan, Datum *Values, const char *Nulls)
paramLI = NULL;
/* Create the QueryDesc object */
- queryDesc = CreateQueryDesc(queryTree, planTree, SPI, NULL,
+ queryDesc = CreateQueryDesc(queryTree, planTree, SPI, pstrdup(name),
paramLI, false);
/* Start the executor */
@@ -1106,7 +1096,8 @@ _SPI_execute(const char *src, int tcount, _SPI_plan *plan)
if (stmt->filename == NULL)
return SPI_ERROR_COPY;
}
- else if (IsA(queryTree->utilityStmt, ClosePortalStmt) ||
+ else if (IsA(queryTree->utilityStmt, DeclareCursorStmt) ||
+ IsA(queryTree->utilityStmt, ClosePortalStmt) ||
IsA(queryTree->utilityStmt, FetchStmt))
return SPI_ERROR_CURSOR;
else if (IsA(queryTree->utilityStmt, TransactionStmt))
@@ -1263,12 +1254,7 @@ _SPI_execute_plan(_SPI_plan *plan, Datum *Values, const char *Nulls,
static int
_SPI_pquery(QueryDesc *queryDesc, bool runit, int tcount)
{
- Query *parseTree = queryDesc->parsetree;
int operation = queryDesc->operation;
- CommandDest dest = queryDesc->dest;
- bool isRetrieveIntoPortal = false;
- bool isRetrieveIntoRelation = false;
- char *intoName = NULL;
int res;
Oid save_lastoid;
@@ -1276,20 +1262,10 @@ _SPI_pquery(QueryDesc *queryDesc, bool runit, int tcount)
{
case CMD_SELECT:
res = SPI_OK_SELECT;
- if (parseTree->isPortal)
- {
- isRetrieveIntoPortal = true;
- intoName = parseTree->into->relname;
- parseTree->isBinary = false; /* */
-
- return SPI_ERROR_CURSOR;
-
- }
- else if (parseTree->into != NULL) /* select into table */
+ if (queryDesc->parsetree->into != NULL) /* select into table */
{
res = SPI_OK_SELINTO;
- isRetrieveIntoRelation = true;
- queryDesc->dest = None; /* */
+ queryDesc->dest = None; /* don't output results anywhere */
}
break;
case CMD_INSERT:
@@ -1315,14 +1291,6 @@ _SPI_pquery(QueryDesc *queryDesc, bool runit, int tcount)
ExecutorStart(queryDesc);
- /*
- * Don't work currently --- need to rearrange callers so that we
- * prepare the portal before doing ExecutorStart() etc. See
- * pquery.c for the correct order of operations.
- */
- if (isRetrieveIntoPortal)
- elog(FATAL, "SPI_select: retrieve into portal not implemented");
-
ExecutorRun(queryDesc, ForwardScanDirection, (long) tcount);
_SPI_current->processed = queryDesc->estate->es_processed;
@@ -1334,7 +1302,7 @@ _SPI_pquery(QueryDesc *queryDesc, bool runit, int tcount)
elog(FATAL, "SPI_select: # of processed tuples check failed");
}
- if (dest == SPI)
+ if (queryDesc->dest == SPI)
{
SPI_processed = _SPI_current->processed;
SPI_lastoid = save_lastoid;
@@ -1367,12 +1335,6 @@ static void
_SPI_cursor_operation(Portal portal, bool forward, int count,
CommandDest dest)
{
- QueryDesc *querydesc;
- EState *estate;
- MemoryContext oldcontext;
- ScanDirection direction;
- CommandDest olddest;
-
/* Check that the portal is valid */
if (!PortalIsValid(portal))
elog(ERROR, "invalid portal in SPI cursor operation");
@@ -1386,53 +1348,9 @@ _SPI_cursor_operation(Portal portal, bool forward, int count,
_SPI_current->processed = 0;
_SPI_current->tuptable = NULL;
- /* Switch to the portals memory context */
- oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
-
- querydesc = PortalGetQueryDesc(portal);
- estate = querydesc->estate;
-
- /* Save the queries command destination and set it to SPI (for fetch) */
- /* or None (for move) */
- olddest = querydesc->dest;
- querydesc->dest = dest;
-
- /* Run the executor like PerformPortalFetch and remember states */
- if (forward)
- {
- if (portal->atEnd)
- direction = NoMovementScanDirection;
- else
- direction = ForwardScanDirection;
-
- ExecutorRun(querydesc, direction, (long) count);
-
- if (estate->es_processed > 0)
- portal->atStart = false; /* OK to back up now */
- if (count <= 0 || (int) estate->es_processed < count)
- portal->atEnd = true; /* we retrieved 'em all */
- }
- else
- {
- if (portal->atStart)
- direction = NoMovementScanDirection;
- else
- direction = BackwardScanDirection;
-
- ExecutorRun(querydesc, direction, (long) count);
-
- if (estate->es_processed > 0)
- portal->atEnd = false; /* OK to go forward now */
- if (count <= 0 || (int) estate->es_processed < count)
- portal->atStart = true; /* we retrieved 'em all */
- }
-
- _SPI_current->processed = estate->es_processed;
-
- /* Restore the old command destination and switch back to callers */
- /* memory context */
- querydesc->dest = olddest;
- MemoryContextSwitchTo(oldcontext);
+ /* Run the cursor */
+ _SPI_current->processed = DoPortalFetch(portal, forward, (long) count,
+ dest);
if (dest == SPI && _SPI_checktuples())
elog(FATAL, "SPI_fetch: # of processed tuples check failed");
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-23 07:17:57 +0000