> [HACKERS] What executes faster?
> Now that I've found the solution for my duplicate key problem,
> I'm wondering what executes faster when I have to check for
> duplicates.
> 1. try to update
> if no row affected -> do the insert
> else done
> 2. do a select
> if row not found -> do the insert
> else do the update
> Another idea I'm thinking about:
> I'm doing the check for duplicate key by myself now.
> Aren't insert commands running faster, if I replace
> an unique index by a not-unique index.
I have solved an almost similar problem.
I have a large table (about 8 milion rows) called radius and a table with
updates and newlines called radiusupdate.
The first thing I tried was 2 queries:
update radius from radiusupdate where radius.pk = radiusupdate.pk
insert into radius
select * from radiusupdate RUwhere RU.pk not in (select pk from radius)
But the second one is obviously not very fast. A "not in" never is... So I
now do things just a little bit different. I added a field to the table
radiusupdate called "newline". It is default set to true. Then I replace
the second query by these two:
update radiusupdate set newline = false from radius Rwhere radiusupdate.pk = radius.pk
insert into radius
select * from radiusupdate RUwhere newline = true
This is a lot faster in my case....
Reinoud