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https://issues.apache.org/jira/browse/CASSANDRA-4694?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13461689#comment-13461689
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Alexey Zotov commented on CASSANDRA-4694:
-----------------------------------------
>From description of populate_io_cache_on_flush option:
{code}
# The following setting populates the page cache on memtable flush and
compaction
# WARNING: Enable this setting only when the whole node's data fits in memory.
# Defaults to: false
# populate_io_cache_on_flush: false
{code}
I'll try to describe my thoughts. Lets imagine that you have a few column
families: cf1 and cf2.
cf1 has a huge amount of data that doesn't fit in memory. Most of queries to
cf1 use only small part of data (so-called hot data). You can use row cache for
processing all these queries.
cf2 has a acceptable size of data for in-memory storing. You can use
populate_io_cache_on_flush option for fast reading of sstables from IO cache
(from memory in fact).
You are right about fix versions. I can migrate it to 1.2 version if it's
needed. Should I do that?
> populate_io_cache_on_flush option should be configurable for each column
> family independently
> ---------------------------------------------------------------------------------------------
>
> Key: CASSANDRA-4694
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4694
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Alexey Zotov
> Assignee: Alexey Zotov
> Priority: Minor
> Labels: cli, core, documentation
> Fix For: 1.1.6
>
> Attachments: cassandra-1.1-4694-populate_io_cache.txt
>
>
> I suggest to configure populate_io_cache_on_flush option for each column
> family. It should be configurable from cassandra-cli and should be stored in
> System keyspace.
> That could be useful if you have a few column families inside single keyspace
> and you need to fit in memory only one of them.
> Patch has been attached. I've been testing it on pseudo-cluster using ccm. So
> I don't have fully confidence about lack of bugs. Please carefully review
> that code.
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