diff options
Diffstat (limited to 'src/backend/executor/nodeIndexscan.c')
| -rw-r--r-- | src/backend/executor/nodeIndexscan.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c index 638b17b07cb..f46bc23ae85 100644 --- a/src/backend/executor/nodeIndexscan.c +++ b/src/backend/executor/nodeIndexscan.c @@ -849,11 +849,39 @@ ExecEndIndexScan(IndexScanState *node) /* ---------------------------------------------------------------- * ExecIndexMarkPos + * + * Note: we assume that no caller attempts to set a mark before having read + * at least one tuple. Otherwise, iss_ScanDesc might still be NULL. * ---------------------------------------------------------------- */ void ExecIndexMarkPos(IndexScanState *node) { + EState *estate = node->ss.ps.state; + + if (estate->es_epqTuple != NULL) + { + /* + * We are inside an EvalPlanQual recheck. If a test tuple exists for + * this relation, then we shouldn't access the index at all. We would + * instead need to save, and later restore, the state of the + * es_epqScanDone flag, so that re-fetching the test tuple is + * possible. However, given the assumption that no caller sets a mark + * at the start of the scan, we can only get here with es_epqScanDone + * already set, and so no state need be saved. + */ + Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid; + + Assert(scanrelid > 0); + if (estate->es_epqTupleSet[scanrelid - 1]) + { + /* Verify the claim above */ + if (!estate->es_epqScanDone[scanrelid - 1]) + elog(ERROR, "unexpected ExecIndexMarkPos call in EPQ recheck"); + return; + } + } + index_markpos(node->iss_ScanDesc); } @@ -864,6 +892,23 @@ ExecIndexMarkPos(IndexScanState *node) void ExecIndexRestrPos(IndexScanState *node) { + EState *estate = node->ss.ps.state; + + if (estate->es_epqTuple != NULL) + { + /* See comments in ExecIndexMarkPos */ + Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid; + + Assert(scanrelid > 0); + if (estate->es_epqTupleSet[scanrelid - 1]) + { + /* Verify the claim above */ + if (!estate->es_epqScanDone[scanrelid - 1]) + elog(ERROR, "unexpected ExecIndexRestrPos call in EPQ recheck"); + return; + } + } + index_restrpos(node->iss_ScanDesc); } |