diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 0b831891fcb..888eeac5151 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -2177,6 +2177,46 @@ subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual) recurse_push_qual(subquery->setOperations, subquery, rte, rti, qual); } + else if (IsA(qual, CurrentOfExpr)) + { + /* + * This is possible when a WHERE CURRENT OF expression is applied to a + * table with row-level security. In that case, the subquery should + * contain precisely one rtable entry for the table, and we can safely + * push the expression down into the subquery. This will cause a TID + * scan subquery plan to be generated allowing the target relation to + * be updated. + * + * Someday we might also be able to use a WHERE CURRENT OF expression + * on a view, but currently the rewriter prevents that, so we should + * never see any other case here, but generate sane error messages in + * case it does somehow happen. + */ + if (subquery->rtable == NIL) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("WHERE CURRENT OF is not supported on a view with no underlying relation"))); + + if (list_length(subquery->rtable) > 1) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("WHERE CURRENT OF is not supported on a view with more than one underlying relation"))); + + if (subquery->hasAggs || subquery->groupClause || subquery->groupingSets || subquery->havingQual) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("WHERE CURRENT OF is not supported on a view with grouping or aggregation"))); + + /* + * Adjust the CURRENT OF expression to refer to the underlying table + * in the subquery, and attach it to the subquery's WHERE clause. + */ + qual = copyObject(qual); + ((CurrentOfExpr *) qual)->cvarno = 1; + + subquery->jointree->quals = + make_and_qual(subquery->jointree->quals, qual); + } else { /* |