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https://issues.apache.org/jira/browse/CASSANDRA-19345?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17812489#comment-17812489
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Brandon Williams commented on CASSANDRA-19345:
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It appears we regressed and lost the optimization from CASSANDRA-8180
> Optimize disk seek using min/max column name meta data when the LIMIT clause
> is used
> ------------------------------------------------------------------------------------
>
> Key: CASSANDRA-19345
> URL: https://issues.apache.org/jira/browse/CASSANDRA-19345
> Project: Cassandra
> Issue Type: Bug
> Components: Legacy/Local Write-Read Paths
> Reporter: Avneesh Pandey
> Priority: Normal
> Fix For: 4.0.x, 4.1.x, 5.0.x, 5.x
>
> Attachments: Jira-Ticket.pdf
>
>
> {code:java}
> CREATE TABLE tracking_details (
> tracker_public_id text,
> updated_at timeuuid,
> details text,
> PRIMARY KEY (tracker_public_id, updated_at)
> ) WITH CLUSTERING ORDER BY (updated_at DESC){code}
> {code:java}
> INSERT INTO tracking_details (tracker_public_id, updated_at, details)
> VALUES('trk_e0544f077f7f4140bf1b961493fa99fe', now(), '{"details":[{...1-3KB
> }]}');{code}
> {code:java}
> nodetool flush trackingdata tracking_details{code}
> {code:java}
> INSERT INTO tracking_details (tracker_public_id, updated_at, details)
> VALUES('trk_e0544f077f7f4140bf1b961493fa99fe', now(), '{"details":[{...1-3KB
> }]}');
> INSERT INTO tracking_details (tracker_public_id, updated_at, details)
> VALUES('trk_e0544f077f7f4140bf1b961493fa99fe', now(), '{"details":[{...1-3KB
> }]}');{code}
> {code:java}
> nodetool flush trackingdata tracking_details{code}
> {code:java}
> Compaction is disabled-
> {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy',
> 'enabled': 'false', 'max_threshold': '32', 'min_threshold': '4'}{code}
> _Each node is reading from both sstables - *Merged data from memtables and 2
> sstables.*_
> I thought this was fixed -
> https://issues.apache.org/jira/browse/CASSANDRA-8180_
> _But somehow C* doesn't optimizes the read path_
> _Tracing attached_
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