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https://issues.apache.org/jira/browse/CALCITE-1265?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15308239#comment-15308239
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Julian Hyde commented on CALCITE-1265:
--------------------------------------
Before you push down offset/fetch you need to be sure that that particular
dialect of SQL supports it, and what is the syntax. I suppose by default you
can assume that the database supports SQL:2008 {{FETCH FIRST}} syntax. But
[wikipedia|https://en.wikipedia.org/wiki/Select_%28SQL%29#Result_limits] lists
many other variants.
FWIW, here is syntax as of SQL:2014:
{code}
<query primary> ::=
<simple table>
| <left paren> <query expression body>
[ <order by clause> ] [ <result offset clause> ] [ <fetch first clause> ]
<right paren>
<order by clause> ::=
ORDER BY <sort specification list>
<result offset clause> ::=
OFFSET <offset row count> { ROW | ROWS }
<fetch first clause> ::=
FETCH { FIRST | NEXT } [ <fetch first quantity> ] { ROW | ROWS } { ONLY |
WITH TIES }
<fetch first quantity> ::=
<fetch first row count>
| <fetch first percentage>
<offset row count> ::=
<simple value specification>
<fetch first row count> ::=
<simple value specification>
<fetch first percentage> ::=
<simple value specification> PERCENT
{code}
For Calcite's purposes, {{OFFSET offset ROWS FETCH FIRST limit ROWS ONLY}} will
be sufficient.
> Implement offset/fetch in JdbcSort
> ----------------------------------
>
> Key: CALCITE-1265
> URL: https://issues.apache.org/jira/browse/CALCITE-1265
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Reporter: Jordan Halterman
> Assignee: Julian Hyde
> Fix For: 1.8.0
>
>
> In {{JdbcSort}}, support for offset/fetch is currently disabled. This seems
> like it may have simply been a result of a lack of support in
> {{RelToSqlConverter}} at the time that commit was made. Since
> {{RelToSqlConverter}} got support for offset/fetch in sorts recently, this
> should be implemented in {{JdbcSort}} as well.
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