[teiid-issues] [JBoss JIRA] Commented: (TEIID-1598) translator scoped result set caching

[Steven Hawkins (JIRA)]

    [ https://issues.jboss.org/browse/TEIID-1598?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12603586#comment-12603586 ] 

Steven Hawkins commented on TEIID-1598:
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MetaMatrix used to function similar to that.  It leads to good cache utilization when you have a small set of fixed user queries.  But then it's usually better just to rely on user query result set caching.  In most other scenarios materialization leads to better cache usage.

That said there are scenarios that do benefit from caching translator queries especially since we don't yet optimize common sub expressions with in a single user query (such as issuing the same translator query multiple times).

Ttl can be configurable via translator property, but there's an issue of when to use cached query results.  In MMX caching needed to be enabled on the connector (translator) and the query had to be cache eligible (non-update, non-transactional, with result set caching enabled).  That last condition meant that unless the source query was shared among many user requests the user result set cache could supersede the source query cache.

> translator scoped result set caching
> ------------------------------------
>
>                 Key: TEIID-1598
>                 URL: https://issues.jboss.org/browse/TEIID-1598
>             Project: Teiid
>          Issue Type: Feature Request
>            Reporter: Mark Addleman
>            Assignee: Steven Hawkins
>            Priority: Minor
>
> Something Steven mentioned in Teiid-1589 got me thinking:  It would be helpful for individual translators to request that Teiid cache results sets that match the query as presented to the execution factory (after the planner is done rewriting the query based on the translator's capabilities).
> I envision a new method on an Execution getCacheTtlMs() where zero or negative indicates that Teiid shouldn't cache the results.

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