Subject Re: [firebird-support] What is better: UPDATE or DELETE + INSERT?
Author Tim Ward
On 16/09/2015 07:51, brucedickinson@... [firebird-support] wrote:

I need to rebuild some records in my database. I have to choices:

1. Firstly I delete set of records and then insert new ones.
2. I update the existing ones.

What solution is preferable? Will scenerio number 1. cause more garbage in database and decrease its performance?

Depends. If you're updating the records in such a way as to make them longer (after run length encoding) enough that each record is then fragmented across more than one database page then resulting performance can become a complete catastrophe (millions of times slower if you're really lucky). If that's your situation you may be better off deleting and recreating.
Tim Ward