[ 
https://issues.apache.org/jira/browse/CASSANDRA-18134?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17688456#comment-17688456
 ] 

Jacek Lewandowski edited comment on CASSANDRA-18134 at 2/14/23 11:08 AM:
-------------------------------------------------------------------------

{quote}Which essential features?{quote}

I meant that having new features disabled after upgrading to the new version, 
the user will not be able to evaluate the new version fully.



was (Author: jlewandowski):
.bq Which essential features?

I meant that having new features disabled after upgrading to the new version, 
the user will not be able to evaluate the new version fully.


> Improve handling of min/max clustering in sstable
> -------------------------------------------------
>
>                 Key: CASSANDRA-18134
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-18134
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Local/SSTable
>            Reporter: Jacek Lewandowski
>            Assignee: Jacek Lewandowski
>            Priority: Normal
>             Fix For: 5.x
>
>
> This patch improves the following things:
> # SSTable metadata will store a covered slice instead of min/max clusterings. 
> The difference is that for slices there is available the type of a bound 
> rather than just a clustering. In particular it will provide the information 
> whether the lower and upper bound of an sstable is opened or closed.
> # SSTable metadata will store a flag whether the SSTable contains any 
> partition level deletions or not
> # The above two changes required to introduce a new major format for SSTables 
> - {{oa}}
> # Single partition read command makes use of the above changes. In particular 
> an sstable can be skipped when it does not intersect with the column filter, 
> does not have partition level deletions and does not have statics; In case 
> there are partition level deletions, but the other conditions are satisfied, 
> only the partition header needs to be accessed (tests attached)
> # Skipping sstables assuming those three conditions are satisfied has been 
> implemented also for partition range queries (tests attached). Also added 
> minor separate statistics to record the number of accessed sstables in 
> partition reads because now not all of them need to be accessed. That 
> statistics is also needed in tests to confirm skipping.
> # Artificial lower bound marker is now an object on its own and is not 
> implemented as a special case of range tombstone bound. Instead it sorts 
> right before the lowest available bound in the data
> # Extended the lower bound optimization usage due the 1 and 2
> # Do not initialize iterator just to get a cached partition and associated 
> columns index. The purpose of using lower bound optimization was to avoid 
> opening an iterator of an sstable if possible.
> See also CASSANDRA-14861
> The changes in this patch include work of [~blambov], [~slebresne], 
> [~jakubzytka] and [~jlewandowski]



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org

Reply via email to