cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Alex Petrov (JIRA)" <>
Subject [jira] [Commented] (CASSANDRA-12102) Refactor and simplify Filtering-related StatementRestriction part
Date Wed, 06 Jul 2016 12:07:11 GMT


Alex Petrov commented on CASSANDRA-12102:

> We actually do index decisions multiple times, on both coordinator (since we do have
some validation that depends on the index) and replicas

I thought that after [CASSANDRA-10215], since index name is serialized as a part of {{ReadCommand}},
it was already completely covered on the coordinator. Might be that [this|]
condition is what you had in mind. 

> we'd etablish some kind of "query plan" on the coordinator

That was exactly what [~blerer] said when we talked about: to introduce the query planner.

In general, I agree on the fact it'd have to wait until the protocol version bump and have
an intersection with [CASSANDRA-10765].

> Refactor and simplify Filtering-related StatementRestriction part
> -----------------------------------------------------------------
>                 Key: CASSANDRA-12102
>                 URL:
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Alex Petrov
> {{RestrictionSet}} hierarchy was significantly improved by [CASSANDRA-11354], although
filtering-related {{Restrictions}} are split with restrictions that would go through the 2i
already in {{RowFilter}}. 
> There's still a clear separation, although it's currently made in {{Index}} implementations
and {{RowFilter}}, by removing things that were handled by {{Index}} for post-filtering like
it's done [here|].

> The primary concern is that we've seen several times that there are many corner-cases,
so we may benefit from splitting columns that are handled by the index from ones that are
handled by post-filtering early in code and possibly keeping them split for all parts of query.

> I suggest to split {{ClusteringColumnRestrictions#addRowFilterTo}} into two parts, {{addIndexRestrictions}}
and {{addFilteringRestrictions}}. The change should be quite simple and make the code simpler
to understand and extend the filtering / indexing rules.
> -One problem, as noted by [~blerer] is that index decision is made on replica, depending
on cardinality, so splitting them too early might not work.- the decision is actually made
on the coordinator after [CASSANDRA-10215], although that might involve a larger refactoring,
although might still help to keep code related to indexing / filtering together.
> We can also validate that all restrictions have been respected (although we can do that
now as well).

This message was sent by Atlassian JIRA

View raw message