[jira] [Created] (IGNITE-6933) Consider executing updates in-place when SQL indexes are present or object size is smaller than the old object size

["Alexey Goncharuk (JIRA)" <ji...@apache.org>]

Alexey Goncharuk created IGNITE-6933:
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             Summary: Consider executing updates in-place when SQL indexes are present or object size is smaller than the old object size
                 Key: IGNITE-6933
                 URL: https://issues.apache.org/jira/browse/IGNITE-6933
             Project: Ignite
          Issue Type: Task
      Security Level: Public (Viewable by anyone)
            Reporter: Alexey Goncharuk


Currently, we are able to execute in-place updates when the new object size exactly matches the old object size and SQL indexes are absent. This leads to a significant performance cost because of extra FreeList updates and extra indexes updates when only one field has changed.

A few possibilities which should be carefully examined:
1) Allow in-place updates if a new object size is smaller than the old object size (allow some space leak into the data page) and defer FreeList update to some later time (introduce a threshold?)
2) Examine (or propagate) the list of changed fields and allow in-place updates if indexed fields did not change
3) Investigate if we can implement an in-place update even with indexed fields - first, remove the value from indexes, then update, then insert value to indexes (note that there is a window when the value is not accessible via indexes in this case, so this is not a safe option). Also, do not update indexes if the indexed value did not change



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