|< < 6 > >|

Postgres MVCC

Indexes — it gets worse

Every row update requires all indexes to be maintained!

|< < 6 > >|

Row update → new row version, with a different ctid.
Each index pointing to the old row version needs to be updated to point to the new row version.
Other databases, even those relying on MVCC, don't have this problem. They update rows in place.