Manual:$wgTagStatisticsNewTable

Miscellaneous settings: $wgTagStatisticsNewTable
Temporarily flag to use change_tag_def table as backend of change tag statistics.
Introduced in version:1.32.0 (Gerrit change 445179; git #9fed3f0f)
Removed in version:1.33.0 (Gerrit change 467957; git #bb07b4a3)
Allowed values:(boolean)
Default value:false

For example in case of Special:Tags. If set to false, it will use change_tag table. Before setting it to true set $wgChangeTagsSchemaMigrationStage to MIGRATION_WRITE_BOTH and run PopulateChangeTagDef maintaince script. It's redundant when Manual:$wgChangeTagsSchemaMigrationStage is set to MIGRATION_NEW.