You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@phoenix.apache.org by "Geoffrey Jacoby (Jira)" <ji...@apache.org> on 2022/05/10 02:58:00 UTC

[jira] [Commented] (PHOENIX-6710) Revert PHOENIX-3842 Turn on back default bloomFilter for Phoenix Tables

    [ https://issues.apache.org/jira/browse/PHOENIX-6710?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17534098#comment-17534098 ] 

Geoffrey Jacoby commented on PHOENIX-6710:
------------------------------------------

[~ankit@apache.org] - Makes sense that there are valid cases where bloom filters would be helpful, such as the ones you list. 

Seems like we'd want it to be configurable for both a default and table-specific override in a CREATE statement.

Also based on PHOENIX-3797, do we need an exception if you try to create a local index on a table with a bloom filter? (Or an exception if you try to turn bloom filters on on a table that already has a local index?)

> Revert PHOENIX-3842 Turn on back default bloomFilter for Phoenix Tables
> -----------------------------------------------------------------------
>
>                 Key: PHOENIX-6710
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-6710
>             Project: Phoenix
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 4.11.0
>            Reporter: Ankit Singhal
>            Assignee: Ankit Singhal
>            Priority: Major
>
> PHOENIX-3842 was done to workaround PHOENIX-3797  to unblock a release, and with the assumption that Phoenix is not used for GETs.
>  
> At one of our users, we saw that they have been doing heavy GETs in their custom coprocessor to check if the key is present or not in the current. At most 99% of the time, the key is not expected to be present during the initial load as keys are expected to be random, but there is still some chance that there is 1% of keys would be duplicated. But in the absence of BloomFilter, HBase has to seek HFile to confirm if the key is not present, which results in regression in performance for about 2x slower.
>  
> Even in use cases like Index maintenance and "ON DUPLICATE KEY" queries will also be impacted without bloom filters.
>  
> As Phoenix is still used for GETs by the users (SELECT query with key as a filter). and we also have constructs that intrinsically do GETs like Index maintenance and
> "On Duplicate key". So I believe it is always better to have a bloom filter should be "ON" by default as I don't also see any implication of it, even if it is not getting used.
>  



--
This message was sent by Atlassian Jira
(v8.20.7#820007)