pt-online-schema-change can silently drop rows

Bug #1225577 reported by Rob Smith on 2013-09-15
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Percona Toolkit moved to

Bug Description

When adding a unique index on a table with pt-online-schema-change, it silently drops rows that fail the unique constraint. There should be the option to check that the row counts are the same before swapping tables.

Yes, we should check to verify that the columns are unique before running, but there are times the tools insert non-unique rows while PTOSC is running, thus having a final check would be best.

tags: added: risk
Changed in percona-toolkit:
status: New → Triaged
Jericho Rivera (jericho-rivera) wrote :

This looks like this has been fixed in pt-osc 3.0.4 with --check-unique-index-change option.

Percona now uses JIRA for bug reports so this bug report is migrated to:

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