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https://jira.jboss.org/jira/browse/TEIID-168?page=com.atlassian.jira.plug...
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Greg Haber commented on TEIID-168:
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I'm actually not particularly interested in end user caching - I was just referring
back to the example in Ramesh's comment on Feb 19.
Let me clarify the use case that I'm really interested in (or, more accurately, that a
current customer of the MetaMatrix product is interested in solving down the road with
Teiid):
-Most of the read requests at this customer are for a relatively small (several GB) set of
reference data, with the data source guaranteed not to change during the business day (all
updated happen during a small, well-defined overnight period).
-Many different end users at the customer access this reference data.
-The current data source systems are overworked so they want to avoid sending more
requests back to these sources.
-They are not interested in setting up additional replication of the data into more
relational databases - that has been their current approach to incrementally add more
capacity, but every additional replication increases complexity of data distribution, and
they end up with the relational database as a bottleneck.
So this is a case where server side intermediate result set caching with heavy use of
in-memory caching mechanisms is a great fit. They can warm the cache at the beginning of
each day by issuing a set of queries for the data to be cached, and set cache expiration
so that the results will be stored by cache for the duration of the business day.
And this is certainly doable without a distributed cache - they would just need to warm
each JVM individually, instead of doing it on the Teeid cluster as a whole and relying on
the distributed cache mechanism to get results to each JVM. But that adds some complexity
to the management of the caching jobs (especially as they grow to have potentially several
dozen JVMs in their installation) - so long term, distributed cache functionality would be
very useful.
In other words, it isn't the performance of the cache population that is the question,
it is the management of the population activity with a large number of JVMs.
Remove resultset caching
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Key: TEIID-168
URL:
https://jira.jboss.org/jira/browse/TEIID-168
Project: Teiid
Issue Type: Feature Request
Components: JDBC Connector, Query Engine
Affects Versions: 6.x
Reporter: Steven Hawkins
Assignee: Steven Hawkins
Fix For: 6.1.0
Resultset caching should be replaced with relation and procedure caching. This would
initially be backed by the buffermanager, based upon hints/costing, and be utilized by the
planner rather than the resolver. It would be good if we also detected the level of
determinism.
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