[
https://issues.apache.org/jira/browse/IGNITE-5571?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16085618#comment-16085618
]
Vladimir Ozerov commented on IGNITE-5571:
-----------------------------------------
[~al.psc], my comments:
1) {{AffinityTopologyVersion}} is never passed from DML processor. Looks like a
bug to me. IMO, we should not pass it to {{querySqlFields}} at all. Instead, we
should ask {{GridQueryProcessor}} for backup filter when we understand it is
needed. Let's remove {{AffinityTopologyVersion}} argument.
2) Please no {{T*}} classes. This is antipattern. Normal value class should be
created instead.
3) {{IgniteH2Indexing:1376}} - incorrect {{distributedJoins}} is set here. I do
not know whether it has any adverse affects, but let's make this code cleaner.
We do not need {{GridH2QueryContext}} at this point. Let's set only after we
calculated final value for {{distributedJoins}} flag.
> Make sure that cache-less execution works as good as cache-based
> ----------------------------------------------------------------
>
> Key: IGNITE-5571
> URL: https://issues.apache.org/jira/browse/IGNITE-5571
> Project: Ignite
> Issue Type: Task
> Components: sql
> Reporter: Vladimir Ozerov
> Assignee: Alexander Paschenko
> Priority: Critical
> Fix For: 2.2
>
>
> Compare the following two methods:
> 1) {{GridQueryProcessor.querySqlFields}} - old good entry point for query
> execution;
> 2) {{GridQueryProcessor.querySqlFieldsNoCache}} - new method for "cache-less"
> execution.
> Note how cache context is used in the first method:
> 1) First, it helps determine whether query can be converted to "local"
> 2) Second, it gets query parallelism of current cache, and if it differs from
> {{1}}, then it turns on {{distributedJoins}}.
> Neither of this happens in the second implementation. Moreover, I had to
> throw an exception for local queries, as I didn't know how to handle them
> properly.
> We need to investigate and fix these two deficiencies somehow. Probably some
> inputs from [~sergi.vladykin] would be required, to understand what is going
> on.
> Our ultimate goal is to make "cache-less" execution as good as the old one.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
