[
https://issues.apache.org/jira/browse/IGNITE-10729?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Igor Seliverstov updated IGNITE-10729:
--------------------------------------
Summary: MVCC TX: Improve VAC (was: MVCC TX: Improvements.)
> MVCC TX: Improve VAC
> --------------------
>
> Key: IGNITE-10729
> URL: https://issues.apache.org/jira/browse/IGNITE-10729
> Project: Ignite
> Issue Type: Improvement
> Components: mvcc
> Reporter: Igor Seliverstov
> Priority: Major
>
> 1) vacuum doesn't have change set, this means it travers all data to find
> invisible entries; hanse it breaks read statistics and make all data set
> "hot" - we should travers data entries instead, and only those entries, which
> was updated (linked to newer versions), moreover, vacuum should travers only
> those data pages, which were updated after last successful vacuum (at least
> one entry on the data page was linked to a never one)
> 2) vacuum travers over partitions instead of data entries, so, there possible
> some races like: reader checks an entry; updater removes this entry from
> partition; vacuum doesn't see the entry and clean TxLog -> reader cannot
> check the entry state with TxLog and gets an exception. This race prevents an
> optimization when all entries, older than last successful vacuum version, are
> considered as COMMITTED (see previous suggestion)
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
