cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Aleksey Yeschenko (JIRA)" <>
Subject [jira] [Resolved] (CASSANDRA-6167) Add end-slice termination predicate
Date Fri, 11 Mar 2016 17:15:39 GMT


Aleksey Yeschenko resolved CASSANDRA-6167.
    Resolution: Later

Closing as Later at least until someone comes up with a decent syntax (most likely UDF-based)
for the feature. 

> Add end-slice termination predicate
> -----------------------------------
>                 Key: CASSANDRA-6167
>                 URL:
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: CQL
>            Reporter: Tupshin Harper
>            Priority: Minor
>              Labels: cql
> When doing performing storage-engine slices, it would sometimes be beneficial to have
the slice terminate for other reasons other than number of columns or min/max cell name.
> Since we are able to look at the contents of each cell as we read it, this is potentially
doable with very little overhead. 
> Probably more challenging than the storage-engine implementation itself, is to come up
with appropriate CQL syntax (Thrift, should we decide to support it, would be trivial).
> Two possibilities ar
> 1) special where function:
> SELECT pk,event from cf WHERE pk IN (1,5,10,11) AND partition_predicate({predicate})
> or a bigger language change, but i think one I prefer. more like:
> 2) SELECT pk,event from cf where pk IN (1,5,10,11) UNTIL PARTITION event {predicate}
> Neither feels perfect, but I do like the fact that the second one at least clearly states
what it is intended to do.
> By using "UNTIL PARTITION", we could re-use the UNTIL keyword to handle other kinds of
early-termination of selects that the coordinator might be able to do, such as stop retrieving
additional rows from shards after a particular criterion was met.

This message was sent by Atlassian JIRA

View raw message