BTW, the new amcheck tool, available in Postgres 10, lets you validate that an index is consistent with its designated sort order (B-Tree operator class). At le

BTW, the new amcheck tool, available in Postgres 10, lets you validate that an index is consistent with its designated sort order (B-Tree operator class). At least you now have some way of detecting the kind of inconsistency you describe. I wrote amcheck, and maintain a version targeting earlier releases of PostgreSQL on Github: https://github.com/petergeoghegan/amcheck https://github.com/petergeoghegan/amcheck