[jira] [Closed] (JAMES-3626) Setting value of a collection inserts tomstone

["Benoit Tellier (Jira)" <se...@james.apache.org>]

     [ https://issues.apache.org/jira/browse/JAMES-3626?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Benoit Tellier closed JAMES-3626.
---------------------------------
    Resolution: Fixed

> Setting value of a collection inserts tomstone
> ----------------------------------------------
>
>                 Key: JAMES-3626
>                 URL: https://issues.apache.org/jira/browse/JAMES-3626
>             Project: James Server
>          Issue Type: Improvement
>          Components: cassandra
>    Affects Versions: master
>            Reporter: Benoit Tellier
>            Priority: Major
>              Labels: cassandra, perf
>             Fix For: 3.7.0
>
>          Time Spent: 1h 40m
>  Remaining Estimate: 0h
>
> https://docs.datastax.com/en/landing_page/doc/landing_page/dataModel.html#dataModel__checkTableStructure
> {code:java}
> Check use of collection types
> When insert or full update of a non-frozen collection occurs, such as replacing the value of the column with another value like UPDATE table SET field = new_value …, Cassandra inserts a tombstone marker to prevent possible overlap with previous data even if data did not previously exist. A large number of tombstones can significantly affect read performance.
> When you know that no previous data exists and to prevent creation of tombstones when inserting data into a set or map (or when performing the full update of a set or map), you can use append operation for columns. For example:
> CREATETABLE test.m1 (
> id int PRIMARY KEY,
> m map<int, text>
> );
> instead of using:
> INSERT INTO test.m1(id, m) VALUES (1, {1:'t1', 2:'t2'}); 
> or
> UPDATE test.m1 SET m = {1:'t1', 2:'t2'} WHERE id = 1; 
> which generate tombstones, execute:
> UPDATE test.m1 SET m = m + {1:'t1', 2:'t2'} WHERE id = 1; 
> which has the same result, but without tombstone generation.
> {code}
> Affected tables:
>  - imapUidTable (use of a non frozen set for user flags)
>       - inserts are done
>       - full updates are done
>       - This table is critical for JMAP performance. Not that it can explain the ~10% performance hit that occurs when reading mailbox with recent inserts versus reading mailboxes without recent inserts.
>  - messageIdTable (use of a non frozen set for user flags)
>       - inserts are done
>       - full updates are done
>       - This table is critical for IMAP performance.
>  - enqueuedMailsV3 (non frozen list data types are mistakenly used for RECIPIENTS and PER_RECIPIENT_SPECIFIC_HEADERS - frozen would be acceptable - map is used for attributed and could be frozen too)
>       - As a temporary measure, we can fix the inserts.
>       - This table is critical to the browse start update performance
>  - mailRepositoryContentV2 (non frozen list data types are mistakenly used for RECIPIENTS and PER_RECIPIENT_SPECIFIC_HEADERS - frozen would be acceptable- map is used for attributed and could be frozen too)
>       - As a temporary measure, we can fix the inserts.
>       - This table is not critical



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