[
https://issues.apache.org/jira/browse/TAJO-939?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14062278#comment-14062278
]
ASF GitHub Bot commented on TAJO-939:
-------------------------------------
Github user jihoonson commented on a diff in the pull request:
https://github.com/apache/tajo/pull/71#discussion_r14946827
--- Diff:
tajo-core/src/main/java/org/apache/tajo/engine/planner/LogicalPlanner.java ---
@@ -712,7 +718,8 @@ public LimitNode visitLimit(PlanContext context,
Stack<Expr> stack, Limit limit)
EvalNode firstFetNum;
LogicalNode child;
if (limit.getFetchFirstNum().getType() == OpType.Literal) {
- firstFetNum = exprAnnotator.createEvalNode(context.plan, block,
limit.getFetchFirstNum());
+ firstFetNum = exprAnnotator.createEvalNode(context.plan, block,
limit.getFetchFirstNum(),
+ NameResolvingMode.RELS_ONLY);
--- End diff --
Would you explain why RELS_ONLY is used for limit, please?
> Refactoring the column resolver in LogicalPlan
> ----------------------------------------------
>
> Key: TAJO-939
> URL: https://issues.apache.org/jira/browse/TAJO-939
> Project: Tajo
> Issue Type: Bug
> Components: planner/optimizer
> Reporter: Hyunsik Choi
> Assignee: Hyunsik Choi
> Fix For: 0.9.0
>
>
> The main role of the column resolver is to find the exact column in a
> relation or a temporal column to which a variable name points. We have used a
> monolithic column resolver to deal with lots of cases.
> But, resolving a name should play different roles according to at which the
> name is placed.
> For example, 1) a column name in select list always points one of fields in
> relations, 2) a column name in WHERE clause can point to one of fields in
> relations or one of aliased temporal fields in select list. If there are
> duplicated, the column name firstly chooses the field in relations. 3) a
> column name in ORDER BY clause is similar to that in WHERE clause, but it
> firstly chooses one of aliased temporal fields in select list.
> The current column resolver does not consider the above rules. As a result,
> it works incorrectly in some cases where a sql statement includes the same
> name references, actually indicating one field in relation and one aliased
> temporal field in select list. We should fix it.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
