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https://issues.apache.org/jira/browse/IGNITE-8386?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vladimir Ozerov updated IGNITE-8386:
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Labels: performance (was: )
> SQL: make sure PK index do not use wrapped objects
> --------------------------------------------------
>
> Key: IGNITE-8386
> URL: https://issues.apache.org/jira/browse/IGNITE-8386
> Project: Ignite
> Issue Type: Task
> Components: sql
> Affects Versions: 2.4
> Reporter: Vladimir Ozerov
> Priority: Major
> Labels: performance
> Fix For: 2.6
>
>
> Currently PK may be built over the whole {{_KEY}} column, i.e. the whole
> binary object. This could happen in two cases:
> 1) Composite PK
> 2) Plain PK but with {{WRAP_KEY}} option.
> This is critical performance issue for two reasons:
> 1) This index is effectively useless and cannot be used in any sensible
> queries; it just wastes space and makes updates slower
> 2) Binary object typically has common header bytes what may lead to excessive
> number of comparisons during index update.
> To mitigate the problem we need to ensure that index is *never* built over
> {{_KEY}}, Instead, we must always extract target columns and build normal
> index over them.
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