Nothing to think of. If you need update go with update otherwise delete and
insert is better.
Trust yourself.
Regards
Bogdan
--- Original message ---
From: 'Leyne, Sean' [email protected] [firebird-support]
<[email protected]>
Date: 16. september 2015 5.40.22 pop.
Subject: RE: [firebird-support] What is better: UPDATE or DELETE + INSERT?
To: [email protected]
They will generate a comparable amount of garbage, but I think updating the
existing records is better than delete + insert, especially if there are also
foreign key references to those records.
I don't think so.
Unless you are updating every column in the row, the UPDATE will generate a
smaller disk footprint, as the new record version will only include the
updated fields -- not a full copy of the row.
Then there is the impact on index structures that Vlad has pointed out.
From a performance point of view, it would be *much faster*, if you are
able to:
- disable all indexes for the target table,
- delete all rows,
- import new rows and
- reactivate all indexes for the target table
This would likely require that you have near-exclusive access/use of the
target table.
Sean
