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https://issues.apache.org/jira/browse/TAJO-1415?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14499587#comment-14499587
]
ASF GitHub Bot commented on TAJO-1415:
--------------------------------------
Github user jihoonson commented on a diff in the pull request:
https://github.com/apache/tajo/pull/454#discussion_r28583531
--- Diff: tajo-plan/src/main/java/org/apache/tajo/plan/ExprAnnotator.java
---
@@ -726,47 +747,125 @@ public EvalNode visitWindowFunction(Context ctx,
Stack<Expr> stack, WindowFuncti
paramTypes[i] = givenArgs[i].getValueType();
}
} else {
- if (windowFunc.getSignature().equalsIgnoreCase("rank")) {
+ if (funcName.equalsIgnoreCase("rank")) {
givenArgs = sortKeys != null ? sortKeys : new EvalNode[0];
}
}
+ // When no window frame is declared in the query, use default value
+ // default window frame is RANGE BETWEEN UNBOUNDED PRECEDING AND
CURRENT ROW
if (frame == null) {
- if (windowSpec.hasOrderBy()) {
- frame = new WindowFrame(new
WindowStartBound(WindowFrameStartBoundType.UNBOUNDED_PRECEDING),
- new WindowEndBound(WindowFrameEndBoundType.CURRENT_ROW));
- } else if (windowFunc.getSignature().equalsIgnoreCase("row_number"))
{
- frame = new WindowFrame(new
WindowStartBound(WindowFrameStartBoundType.UNBOUNDED_PRECEDING),
- new
WindowEndBound(WindowFrameEndBoundType.UNBOUNDED_FOLLOWING));
+ frame = new LogicalWindowFrame(WindowFrameUnit.RANGE, new
LogicalWindowBound(WindowFrameBoundType.UNBOUNDED_PRECEDING),
+ new LogicalWindowBound(WindowFrameBoundType.CURRENT_ROW));
+ }
+
+ // set Function Type to determine whether window frame is applied or
not
+ // NONFRAMABLE: builtin window function that works on entire
partition
+ // FRAMABLE: builtin window function that works on window frame
+ // AGGREGATION: aggregation functions that work on window frame
--- End diff --
How about moving these comments to the code where the enum is defined?
> Window frame support
> --------------------
>
> Key: TAJO-1415
> URL: https://issues.apache.org/jira/browse/TAJO-1415
> Project: Tajo
> Issue Type: Sub-task
> Components: distributed query plan, parser, physical operator,
> planner/optimizer
> Reporter: Keuntae Park
> Assignee: Keuntae Park
> Fix For: window function
>
>
> We can define frame clause in window definition like
> {code}
> [ RANGE | ROWS ] frame_start
> [ RANGE | ROWS ] BETWEEN frame_start AND frame_end
> {code}
> , where frame_start and frame_end can be one of
> {code}
> UNBOUNDED PRECEDING
> value PRECEDING
> CURRENT ROW
> value FOLLOWING
> UNBOUNDED FOLLOWING
> {code}
> According to the window functions description of
> PostgreSQL(http://www.postgresql.org/docs/9.4/static/functions-window.html),
> there are two types of window functions based on window frame support.
> 1) row_number, rank, dense_rank, percent_rank, cume_dist, tile, lag and lead:
> these functions only work within window partition, which means window frame
> has no effect on these functions.
> 2) first_value, last_value, nth_value, and aggregation function as as window
> function: these functions should work with rows within window frame.
> Currently, Tajo parser recognize the window frame grammar but windowAggExec
> does not use that information.
> It works as if window frame is set as "RANGE BETWEEN UNBOUND PROCEEDING AND
> UNBOUNDED FOLLOWING", which is different from the default window frame
> setting of most DBMSs "RANGE BETWEEN UNBOUND PROCEEDING AND CURRENT ROW".
> Following should be done:
> 1) Applying correct default window frame for first_value, last_value,
> nth_value, and aggregation functions .
> 2) Supporting various window frame expressions.
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