On 2016/01/12 2:36, Alvaro Herrera wrote:
I wonder,--- 2166,2213 ---- } /* ! * If rel is a base relation, detect whether any system columns are ! * requested from the rel. (If rel is a join relation, rel->relid will be ! * 0, but there can be no Var in the target list with relid 0, so we skip ! * this in that case. Note that any such system columns are assumed to be ! * contained in fdw_scan_tlist, so we never need fsSystemCol to be true in ! * the joinrel case.) This is a bit of a kluge and might go away someday, ! * so we intentionally leave it out of the API presented to FDWs. */ ! scan_plan->fsSystemCol = false; ! if (scan_relid > 0) { ! Bitmapset *attrs_used = NULL; ! ListCell *lc; ! int i; ! /* ! * First, examine all the attributes needed for joins or final output. ! * Note: we must look at reltargetlist, not the attr_needed data, ! * because attr_needed isn't computed for inheritance child rels. ! */ ! pull_varattnos((Node *) rel->reltargetlist, scan_relid, &attrs_used); ! /* Add all the attributes used by restriction clauses. */ ! foreach(lc, rel->baserestrictinfo) { ! RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc); ! ! pull_varattnos((Node *) rinfo->clause, scan_relid, &attrs_used); } ! /* Now, are any system columns requested from rel? */ ! for (i = FirstLowInvalidHeapAttributeNumber + 1; i < 0; i++) ! { ! if (bms_is_member(i - FirstLowInvalidHeapAttributeNumber, attrs_used)) ! { ! scan_plan->fsSystemCol = true; ! break; ! } ! } ! ! bms_free(attrs_used); ! } return scan_plan; }Would it make sense to call pull_varattnos(reltargetlist), then walk the bitmapset and break if we see a system column, then call pull_varattnos() on the rinfo->clause? That way, if the targetlist request a system column we don't have to walk the RestrictInfos.
Seems like a good idea. Will update the patch. Best regards, Etsuro Fujita -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
