/* ---------------------------------------------------------------- * ExecInitBitmapHeapScan * * Initializes the scan's state information. * ---------------------------------------------------------------- */ BitmapHeapScanState * ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) { BitmapHeapScanState *scanstate; Relation currentRelation; int io_concurrency; /* check for unsupported flags */ Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK))); /* * Assert caller didn't ask for an unsafe snapshot --- see comments at * head of file. */ Assert(IsMVCCSnapshot(estate->es_snapshot)); /* * create state structure */ scanstate = makeNode(BitmapHeapScanState); scanstate->ss.ps.plan = (Plan *) node; scanstate->ss.ps.state = estate; scanstate->tbm = NULL; scanstate->tbmiterator = NULL; scanstate->tbmres = NULL; scanstate->exact_pages = 0; scanstate->lossy_pages = 0; scanstate->prefetch_iterator = NULL; scanstate->prefetch_pages = 0; scanstate->prefetch_target = 0; /* may be updated below */ scanstate->prefetch_maximum = target_prefetch_pages; /* * Miscellaneous initialization * * create expression context for node */ ExecAssignExprContext(estate, &scanstate->ss.ps); scanstate->ss.ps.ps_TupFromTlist = false; /* * initialize child expressions */ scanstate->ss.ps.targetlist = (List *) ExecInitExpr((Expr *) node->scan.plan.targetlist, (PlanState *) scanstate); scanstate->ss.ps.qual = (List *) ExecInitExpr((Expr *) node->scan.plan.qual, (PlanState *) scanstate); scanstate->bitmapqualorig = (List *) ExecInitExpr((Expr *) node->bitmapqualorig, (PlanState *) scanstate); /* * tuple table initialization */ ExecInitResultTupleSlot(estate, &scanstate->ss.ps); ExecInitScanTupleSlot(estate, &scanstate->ss); /* * open the base relation and acquire appropriate lock on it. */ currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags); /* * Determine the maximum for prefetch_target. If the tablespace has a * specific IO concurrency set, use that to compute the corresponding * maximum value; otherwise, we already initialized to the value computed * by the GUC machinery. */ io_concurrency = get_tablespace_io_concurrency(currentRelation->rd_rel->reltablespace); if (io_concurrency != effective_io_concurrency) { double maximum; if (ComputeIoConcurrency(io_concurrency, &maximum)) scanstate->prefetch_maximum = rint(maximum); } scanstate->ss.ss_currentRelation = currentRelation; /* * Even though we aren't going to do a conventional seqscan, it is useful * to create a HeapScanDesc --- most of the fields in it are usable. */ scanstate->ss.ss_currentScanDesc = heap_beginscan_bm(currentRelation, estate->es_snapshot, 0, NULL); /* * get the scan type from the relation descriptor. */ ExecAssignScanType(&scanstate->ss, RelationGetDescr(currentRelation)); /* * Initialize result tuple type and projection info. */ ExecAssignResultTypeFromTL(&scanstate->ss.ps); ExecAssignScanProjectionInfo(&scanstate->ss); /* * initialize child nodes * * We do this last because the child nodes will open indexscans on our * relation's indexes, and we want to be sure we have acquired a lock on * the relation first. */ outerPlanState(scanstate) = ExecInitNode(outerPlan(node), estate, eflags); /* * all done. */ return scanstate; }
/* ---------------------------------------------------------------- * ExecInitBitmapHeapScan * * Initializes the scan's state information. * ---------------------------------------------------------------- */ BitmapHeapScanState * ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) { BitmapHeapScanState *scanstate; Relation currentRelation; int io_concurrency; /* check for unsupported flags */ Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK))); /* * Assert caller didn't ask for an unsafe snapshot --- see comments at * head of file. */ Assert(IsMVCCSnapshot(estate->es_snapshot)); /* * create state structure */ scanstate = makeNode(BitmapHeapScanState); scanstate->ss.ps.plan = (Plan *) node; scanstate->ss.ps.state = estate; scanstate->ss.ps.ExecProcNode = ExecBitmapHeapScan; scanstate->tbm = NULL; scanstate->tbmiterator = NULL; scanstate->tbmres = NULL; scanstate->skip_fetch = false; scanstate->vmbuffer = InvalidBuffer; scanstate->pvmbuffer = InvalidBuffer; scanstate->exact_pages = 0; scanstate->lossy_pages = 0; scanstate->prefetch_iterator = NULL; scanstate->prefetch_pages = 0; scanstate->prefetch_target = 0; /* may be updated below */ scanstate->prefetch_maximum = target_prefetch_pages; scanstate->pscan_len = 0; scanstate->initialized = false; scanstate->shared_tbmiterator = NULL; scanstate->shared_prefetch_iterator = NULL; scanstate->pstate = NULL; /* * We can potentially skip fetching heap pages if we do not need any * columns of the table, either for checking non-indexable quals or for * returning data. This test is a bit simplistic, as it checks the * stronger condition that there's no qual or return tlist at all. But in * most cases it's probably not worth working harder than that. */ scanstate->can_skip_fetch = (node->scan.plan.qual == NIL && node->scan.plan.targetlist == NIL); /* * Miscellaneous initialization * * create expression context for node */ ExecAssignExprContext(estate, &scanstate->ss.ps); /* * open the scan relation */ currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags); /* * initialize child nodes */ outerPlanState(scanstate) = ExecInitNode(outerPlan(node), estate, eflags); /* * get the scan type from the relation descriptor. */ ExecInitScanTupleSlot(estate, &scanstate->ss, RelationGetDescr(currentRelation), &TTSOpsBufferHeapTuple); /* * Initialize result type and projection. */ ExecInitResultTypeTL(&scanstate->ss.ps); ExecAssignScanProjectionInfo(&scanstate->ss); /* * initialize child expressions */ scanstate->ss.ps.qual = ExecInitQual(node->scan.plan.qual, (PlanState *) scanstate); scanstate->bitmapqualorig = ExecInitQual(node->bitmapqualorig, (PlanState *) scanstate); /* * Determine the maximum for prefetch_target. If the tablespace has a * specific IO concurrency set, use that to compute the corresponding * maximum value; otherwise, we already initialized to the value computed * by the GUC machinery. */ io_concurrency = get_tablespace_io_concurrency(currentRelation->rd_rel->reltablespace); if (io_concurrency != effective_io_concurrency) { double maximum; if (ComputeIoConcurrency(io_concurrency, &maximum)) scanstate->prefetch_maximum = rint(maximum); } scanstate->ss.ss_currentRelation = currentRelation; /* * Even though we aren't going to do a conventional seqscan, it is useful * to create a HeapScanDesc --- most of the fields in it are usable. */ scanstate->ss.ss_currentScanDesc = heap_beginscan_bm(currentRelation, estate->es_snapshot, 0, NULL); /* * all done. */ return scanstate; }