[jira] [Commented] (CALCITE-4705) Support hints like /*+ skewjoin(a(c0, c1)) */
[
https://issues.apache.org/jira/browse/CALCITE-4705?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17564604#comment-17564604
]
Haisheng Yuan commented on CALCITE-4705:
I don't know any other databases that support skew join hint besides these two.
> Support hints like /*+ skewjoin(a(c0, c1)) */
> -
>
> Key: CALCITE-4705
> URL: https://issues.apache.org/jira/browse/CALCITE-4705
> Project: Calcite
> Issue Type: Improvement
> Components: core
>Affects Versions: 1.27.0
>Reporter: jibiyr
>Assignee: jibiyr
>Priority: Minor
>
> Dear community,
> calcite parse support hint now,but it can not parse hint like follow,
> _*select /*+ skewjoin(a(c0, c1)) */ * from T0 a join T1 b on a.c0 = b.c0,*_
> this is the bnf which is calcite supported now,
> {code:java}
> //
> hint:
> hintName
> | hintName '(' hintOptions ')'
> hintOptions:
> hintKVOption [, hintKVOption ]*
> | optionName [, optionName ]*
> | optionValue [, optionValue ]*
> hintKVOption:
> optionName '=' stringLiteral
> | stringLiteral '=' stringLiteral
> optionValue:
> stringLiteral
> | numericLiteral
> {code}
> I think the hintOptions should support the expression pattern,like a(c0,c1).
> And this pattern can be parsed by spark/presto now.
>
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[jira] [Commented] (CALCITE-4705) Support hints like /*+ skewjoin(a(c0, c1)) */
[
https://issues.apache.org/jira/browse/CALCITE-4705?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17564541#comment-17564541
]
Jiajun Xie commented on CALCITE-4705:
-
In databricks:
[https://docs.databricks.com/delta/join-performance/skew-join.html]
The hint is named as *skew,* and the options contain string and number,
calcite can't parse it. So I create new Jira ticket to disscuss.
{code:java}
SELECT /*+ SKEW('orders', 'o_custId', 0) */ * FROM orders, customers WHERE
o_custId = c_custId {code}
I only found */*+ skewjoin(a(c0, c1)) */* in MaxCompute:
https://help.aliyun.com/document_detail/203410.html
Any other database support it? [~hyuan]
> Support hints like /*+ skewjoin(a(c0, c1)) */
> -
>
> Key: CALCITE-4705
> URL: https://issues.apache.org/jira/browse/CALCITE-4705
> Project: Calcite
> Issue Type: Improvement
> Components: core
>Affects Versions: 1.27.0
>Reporter: jibiyr
>Assignee: jibiyr
>Priority: Minor
>
> Dear community,
> calcite parse support hint now,but it can not parse hint like follow,
> _*select /*+ skewjoin(a(c0, c1)) */ * from T0 a join T1 b on a.c0 = b.c0,*_
> this is the bnf which is calcite supported now,
> {code:java}
> //
> hint:
> hintName
> | hintName '(' hintOptions ')'
> hintOptions:
> hintKVOption [, hintKVOption ]*
> | optionName [, optionName ]*
> | optionValue [, optionValue ]*
> hintKVOption:
> optionName '=' stringLiteral
> | stringLiteral '=' stringLiteral
> optionValue:
> stringLiteral
> | numericLiteral
> {code}
> I think the hintOptions should support the expression pattern,like a(c0,c1).
> And this pattern can be parsed by spark/presto now.
>
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[jira] [Commented] (CALCITE-4705) Support hints like /*+ skewjoin(a(c0, c1)) */
[
https://issues.apache.org/jira/browse/CALCITE-4705?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17561736#comment-17561736
]
Jiajun Xie commented on CALCITE-4705:
-
[~yanjing.wang] , it's not correct. Spark can parse any primary expression, but
it can't resolved many expression. You can see the unit
test:[https://github.com/apache/spark/blob/master/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/ResolveHintsSuite.scala#L199]
This is because:
[https://github.com/apache/spark/blob/efe43306fcab18f076f755c81c0406ebc1a5fee9/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveHints.scala#L204]
[~yr] , Are you still working on this? I want to take it.
> Support hints like /*+ skewjoin(a(c0, c1)) */
> -
>
> Key: CALCITE-4705
> URL: https://issues.apache.org/jira/browse/CALCITE-4705
> Project: Calcite
> Issue Type: Improvement
> Components: core
>Affects Versions: 1.27.0
>Reporter: jibiyr
>Assignee: jibiyr
>Priority: Minor
>
> Dear community,
> calcite parse support hint now,but it can not parse hint like follow,
> _*select /*+ skewjoin(a(c0, c1)) */ * from T0 a join T1 b on a.c0 = b.c0,*_
> this is the bnf which is calcite supported now,
> {code:java}
> //
> hint:
> hintName
> | hintName '(' hintOptions ')'
> hintOptions:
> hintKVOption [, hintKVOption ]*
> | optionName [, optionName ]*
> | optionValue [, optionValue ]*
> hintKVOption:
> optionName '=' stringLiteral
> | stringLiteral '=' stringLiteral
> optionValue:
> stringLiteral
> | numericLiteral
> {code}
> I think the hintOptions should support the expression pattern,like a(c0,c1).
> And this pattern can be parsed by spark/presto now.
>
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