[teiid-issues] [JBoss JIRA] Updated: (TEIID-1376) Add support for pushing joins through a union
Steven Hawkins (JIRA)
jira-events at lists.jboss.org
Fri Dec 17 12:59:18 EST 2010
[ https://issues.jboss.org/browse/TEIID-1376?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Steven Hawkins updated TEIID-1376:
----------------------------------
Description:
Given a query structure such as:
inner join
union all
a
b
union all
c
d
where a,b,c,d are access nodes to a source that supports joins and there is a constant column projected by each union branch and that column is used in the join predicates, then we should be able examine
union all
inner join
a
c
inner join
a
d
...
to determine if any of the joins will no longer be necessary.
This is a possible pattern in a multi-source or partitioning scenario.
In some scenarios there may not be an actual projected literal, which could be accommodated if a foreign key could be marked as partitioned.
was:
Given a query structure such as:
inner join
union all
a
b
union all
c
d
where a,b,c,d are access nodes to a source that supports joins and there is a constant column projected by each union branch and that column is used in the join predicates, then we should be able examine
union all
inner join
a
b
inner join
a
c
...
to determine if any of the joins will no longer be necessary.
This is a possible pattern in a multi-source or partitioning scenario.
In some scenarios there may not be an actual projected literal, which could be accommodated if a foreign key could be marked as partitioned.
> Add support for pushing joins through a union
> ---------------------------------------------
>
> Key: TEIID-1376
> URL: https://issues.jboss.org/browse/TEIID-1376
> Project: Teiid
> Issue Type: Feature Request
> Components: Query Engine
> Affects Versions: 7.2
> Reporter: Steven Hawkins
> Assignee: Steven Hawkins
> Fix For: 7.3
>
>
> Given a query structure such as:
> inner join
> union all
> a
> b
> union all
> c
> d
> where a,b,c,d are access nodes to a source that supports joins and there is a constant column projected by each union branch and that column is used in the join predicates, then we should be able examine
> union all
> inner join
> a
> c
> inner join
> a
> d
> ...
> to determine if any of the joins will no longer be necessary.
> This is a possible pattern in a multi-source or partitioning scenario.
> In some scenarios there may not be an actual projected literal, which could be accommodated if a foreign key could be marked as partitioned.
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