[teiid-issues] [JBoss JIRA] (TEIID-5925) Support a materialization on failure action of no cache

[Steven Hawkins (Jira)]

    [ https://issues.redhat.com/browse/TEIID-5925?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14018668#comment-14018668 ] 

Steven Hawkins commented on TEIID-5925:
---------------------------------------

Admittedly there's not a lot of detail in the stackoverflow post, but as described there the pg source is acting as a materialization of the excel data.  Only if pg is not available, then consult the excel source.  So cache first and if not available then source - which looks like a different on error action.

> The way I understood that is, the user always wants to go source without intermediate cache in Teiid, if source not available then failover to the next source that is configured. Will this method avoids that scenario?

That's a more general failover scenario.  It's made more complicated if you are dealing with heterogeneous sources (pg/excel) as the source metadata won't necessarily line-up across failover targets (multi-source has the same issue) . 

Ideally we lean on source support where possible to handle failover.  There were even a few JDBC projects over the years to provide generic clustering/failover at the driver level.  I'd go so far as to say in most homogeneous scenarios involving sql/nosql sources there would be source support of some kind.

I see the appeal of fleshing out a general failover feature as that leads to other source query modes, such as parallel execution to obtain the first/fastest result, etc.  However if it's primarily for what looks to be a materialization scenario, I'd start there.

> Support a materialization on failure action of no cache
> -------------------------------------------------------
>
>                 Key: TEIID-5925
>                 URL: https://issues.redhat.com/browse/TEIID-5925
>             Project: Teiid
>          Issue Type: Enhancement
>          Components: Query Engine
>            Reporter: Steven Hawkins
>            Assignee: Steven Hawkins
>            Priority: Major
>             Fix For: 13.x
>
>   Original Estimate: 4 hours
>  Remaining Estimate: 4 hours
>
> The stackoverflow user is asking about a failover scenario, which would actually be implemented with materialization - but we lack an on failure option to describe "just use the original view definition".



--
This message was sent by Atlassian Jira
(v7.13.8#713008)