[
https://issues.apache.org/jira/browse/CASSANDRA-18134?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17688479#comment-17688479
]
Benedict Elliott Smith commented on CASSANDRA-18134:
----------------------------------------------------
See the roadmap discussion:
https://lists.apache.org/thread/2mrz6m0dbtd6bhlxgpy9rc5fq1jwbyjk.
This discussion passed with general assent, and this proposal was summarised as
agreed by Benjamin. The content of the proposal was that we would not upgrade
sstable versions (or anything incompatible with downgrade) by default during
upgrade, and so I believe this is essentially project policy. But if you want
to revisit it, feel free to open another DISCUSS thread to pick up where this
left off. I am certain I have had discussions elsewhere about this, either on
Slack of Jira, but I won't go hunting for them.
> 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
