diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 70 | ||||
| -rw-r--r-- | src/backend/executor/execAmi.c | 49 | ||||
| -rw-r--r-- | src/backend/executor/nodeSeqscan.c | 38 | ||||
| -rw-r--r-- | src/backend/executor/nodeTidscan.c | 30 | ||||
| -rw-r--r-- | src/backend/executor/nodeValuesscan.c | 25 |
5 files changed, 13 insertions, 199 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index c6e1eb79b2..df4853bad1 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -27,8 +27,6 @@ * heap_multi_insert - insert multiple tuples into a relation * heap_delete - delete a tuple from a relation * heap_update - replace a tuple in a relation with another tuple - * heap_markpos - mark scan position - * heap_restrpos - restore position to marked location * heap_sync - sync heap, for when no WAL has been written * * NOTES @@ -280,9 +278,6 @@ initscan(HeapScanDesc scan, ScanKey key, bool is_rescan) scan->rs_cbuf = InvalidBuffer; scan->rs_cblock = InvalidBlockNumber; - /* we don't have a marked position... */ - ItemPointerSetInvalid(&(scan->rs_mctid)); - /* page-at-a-time fields are always invalid when not rs_inited */ /* @@ -6317,71 +6312,6 @@ heap_tuple_needs_freeze(HeapTupleHeader tuple, TransactionId cutoff_xid, return false; } -/* ---------------- - * heap_markpos - mark scan position - * ---------------- - */ -void -heap_markpos(HeapScanDesc scan) -{ - /* Note: no locking manipulations needed */ - - if (scan->rs_ctup.t_data != NULL) - { - scan->rs_mctid = scan->rs_ctup.t_self; - if (scan->rs_pageatatime) - scan->rs_mindex = scan->rs_cindex; - } - else - ItemPointerSetInvalid(&scan->rs_mctid); -} - -/* ---------------- - * heap_restrpos - restore position to marked location - * ---------------- - */ -void -heap_restrpos(HeapScanDesc scan) -{ - /* XXX no amrestrpos checking that ammarkpos called */ - - if (!ItemPointerIsValid(&scan->rs_mctid)) - { - scan->rs_ctup.t_data = NULL; - - /* - * unpin scan buffers - */ - if (BufferIsValid(scan->rs_cbuf)) - ReleaseBuffer(scan->rs_cbuf); - scan->rs_cbuf = InvalidBuffer; - scan->rs_cblock = InvalidBlockNumber; - scan->rs_inited = false; - } - else - { - /* - * If we reached end of scan, rs_inited will now be false. We must - * reset it to true to keep heapgettup from doing the wrong thing. - */ - scan->rs_inited = true; - scan->rs_ctup.t_self = scan->rs_mctid; - if (scan->rs_pageatatime) - { - scan->rs_cindex = scan->rs_mindex; - heapgettup_pagemode(scan, - NoMovementScanDirection, - 0, /* needn't recheck scan keys */ - NULL); - } - else - heapgettup(scan, - NoMovementScanDirection, - 0, /* needn't recheck scan keys */ - NULL); - } -} - /* * If 'tuple' contains any visible XID greater than latestRemovedXid, * ratchet forwards latestRemovedXid to the greatest one found. diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c index 643aaace3a..7027d7f805 100644 --- a/src/backend/executor/execAmi.c +++ b/src/backend/executor/execAmi.c @@ -271,16 +271,20 @@ ExecReScan(PlanState *node) * ExecMarkPos * * Marks the current scan position. + * + * NOTE: mark/restore capability is currently needed only for plan nodes + * that are the immediate inner child of a MergeJoin node. Since MergeJoin + * requires sorted input, there is never any need to support mark/restore in + * node types that cannot produce sorted output. There are some cases in + * which a node can pass through sorted data from its child; if we don't + * implement mark/restore for such a node type, the planner compensates by + * inserting a Material node above that node. */ void ExecMarkPos(PlanState *node) { switch (nodeTag(node)) { - case T_SeqScanState: - ExecSeqMarkPos((SeqScanState *) node); - break; - case T_IndexScanState: ExecIndexMarkPos((IndexScanState *) node); break; @@ -289,14 +293,6 @@ ExecMarkPos(PlanState *node) ExecIndexOnlyMarkPos((IndexOnlyScanState *) node); break; - case T_TidScanState: - ExecTidMarkPos((TidScanState *) node); - break; - - case T_ValuesScanState: - ExecValuesMarkPos((ValuesScanState *) node); - break; - case T_CustomScanState: ExecCustomMarkPos((CustomScanState *) node); break; @@ -338,10 +334,6 @@ ExecRestrPos(PlanState *node) { switch (nodeTag(node)) { - case T_SeqScanState: - ExecSeqRestrPos((SeqScanState *) node); - break; - case T_IndexScanState: ExecIndexRestrPos((IndexScanState *) node); break; @@ -350,14 +342,6 @@ ExecRestrPos(PlanState *node) ExecIndexOnlyRestrPos((IndexOnlyScanState *) node); break; - case T_TidScanState: - ExecTidRestrPos((TidScanState *) node); - break; - - case T_ValuesScanState: - ExecValuesRestrPos((ValuesScanState *) node); - break; - case T_CustomScanState: ExecCustomRestrPos((CustomScanState *) node); break; @@ -386,14 +370,6 @@ ExecRestrPos(PlanState *node) * This is used during planning and so must accept a Path, not a Plan. * We keep it here to be adjacent to the routines above, which also must * know which plan types support mark/restore. - * - * XXX Ideally, all plan node types would support mark/restore, and this - * wouldn't be needed. For now, this had better match the routines above. - * - * (However, since the only present use of mark/restore is in mergejoin, - * there is no need to support mark/restore in any plan type that is not - * capable of generating ordered output. So the seqscan, tidscan, - * and valuesscan support is actually useless code at present.) */ bool ExecSupportsMarkRestore(Path *pathnode) @@ -405,11 +381,8 @@ ExecSupportsMarkRestore(Path *pathnode) */ switch (pathnode->pathtype) { - case T_SeqScan: case T_IndexScan: case T_IndexOnlyScan: - case T_TidScan: - case T_ValuesScan: case T_Material: case T_Sort: return true; @@ -426,7 +399,11 @@ ExecSupportsMarkRestore(Path *pathnode) * Although Result supports mark/restore if it has a child plan * that does, we presently come here only for ResultPath nodes, * which represent Result plans without a child plan. So there is - * nothing to recurse to and we can just say "false". + * nothing to recurse to and we can just say "false". (This means + * that Result's support for mark/restore is in fact dead code. + * We keep it since it's not much code, and someday the planner + * might be smart enough to use it. That would require making + * this function smarter too, of course.) */ Assert(IsA(pathnode, ResultPath)); return false; diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c index ab13e4729e..53cfda5f9c 100644 --- a/src/backend/executor/nodeSeqscan.c +++ b/src/backend/executor/nodeSeqscan.c @@ -19,8 +19,6 @@ * ExecInitSeqScan creates and initializes a seqscan node. * ExecEndSeqScan releases any storage allocated. * ExecReScanSeqScan rescans the relation - * ExecSeqMarkPos marks scan position - * ExecSeqRestrPos restores scan position */ #include "postgres.h" @@ -274,39 +272,3 @@ ExecReScanSeqScan(SeqScanState *node) ExecScanReScan((ScanState *) node); } - -/* ---------------------------------------------------------------- - * ExecSeqMarkPos(node) - * - * Marks scan position. - * ---------------------------------------------------------------- - */ -void -ExecSeqMarkPos(SeqScanState *node) -{ - HeapScanDesc scan = node->ss_currentScanDesc; - - heap_markpos(scan); -} - -/* ---------------------------------------------------------------- - * ExecSeqRestrPos - * - * Restores scan position. - * ---------------------------------------------------------------- - */ -void -ExecSeqRestrPos(SeqScanState *node) -{ - HeapScanDesc scan = node->ss_currentScanDesc; - - /* - * Clear any reference to the previously returned tuple. This is needed - * because the slot is simply pointing at scan->rs_cbuf, which - * heap_restrpos will change; we'd have an internally inconsistent slot if - * we didn't do this. - */ - ExecClearTuple(node->ss_ScanTupleSlot); - - heap_restrpos(scan); -} diff --git a/src/backend/executor/nodeTidscan.c b/src/backend/executor/nodeTidscan.c index 3560f8440a..1b2454d49d 100644 --- a/src/backend/executor/nodeTidscan.c +++ b/src/backend/executor/nodeTidscan.c @@ -19,8 +19,6 @@ * ExecInitTidScan creates and initializes state info. * ExecReScanTidScan rescans the tid relation. * ExecEndTidScan releases all storage. - * ExecTidMarkPos marks scan position. - * ExecTidRestrPos restores scan position. */ #include "postgres.h" @@ -441,34 +439,6 @@ ExecEndTidScan(TidScanState *node) } /* ---------------------------------------------------------------- - * ExecTidMarkPos - * - * Marks scan position by marking the current tid. - * Returns nothing. - * ---------------------------------------------------------------- - */ -void -ExecTidMarkPos(TidScanState *node) -{ - node->tss_MarkTidPtr = node->tss_TidPtr; -} - -/* ---------------------------------------------------------------- - * ExecTidRestrPos - * - * Restores scan position by restoring the current tid. - * Returns nothing. - * - * XXX Assumes previously marked scan position belongs to current tid - * ---------------------------------------------------------------- - */ -void -ExecTidRestrPos(TidScanState *node) -{ - node->tss_TidPtr = node->tss_MarkTidPtr; -} - -/* ---------------------------------------------------------------- * ExecInitTidScan * * Initializes the tid scan's state information, creates diff --git a/src/backend/executor/nodeValuesscan.c b/src/backend/executor/nodeValuesscan.c index d49a473386..8365b8c99f 100644 --- a/src/backend/executor/nodeValuesscan.c +++ b/src/backend/executor/nodeValuesscan.c @@ -246,7 +246,6 @@ ExecInitValuesScan(ValuesScan *node, EState *estate, int eflags) /* * Other node-specific setup */ - scanstate->marked_idx = -1; scanstate->curr_idx = -1; scanstate->array_len = list_length(node->values_lists); @@ -294,30 +293,6 @@ ExecEndValuesScan(ValuesScanState *node) } /* ---------------------------------------------------------------- - * ExecValuesMarkPos - * - * Marks scan position. - * ---------------------------------------------------------------- - */ -void -ExecValuesMarkPos(ValuesScanState *node) -{ - node->marked_idx = node->curr_idx; -} - -/* ---------------------------------------------------------------- - * ExecValuesRestrPos - * - * Restores scan position. - * ---------------------------------------------------------------- - */ -void -ExecValuesRestrPos(ValuesScanState *node) -{ - node->curr_idx = node->marked_idx; -} - -/* ---------------------------------------------------------------- * ExecReScanValuesScan * * Rescans the relation. |