Type: Regression Bug
Affects Version/s: 7.0.0 DXP FP8, Master
Queries to delete inside UpgradeMessageBoards#deleteEmptyMBDiscussion are not efficient in MySQL, because deletes with subselects doesn't use optimizer (see https://dev.mysql.com/doc/refman/5.6/en/subquery-optimization.html)
Steps to Reproduce:
- In a 6.2.X clean bundle, with MySQL, insert several (for example 100000) journal articles.
- Check that equivalent entries are inserted in AssetEntry, MBDiscussion, MBMessage, MBThread .
- Execute upgrade to DXP
UpgradeMessageBoards step should not take more than 10 minutes.
UpgradeMessageBoards step is taking more than an hour.