At 02:44 PM 21-05-02 +0000, you wrote:

>uhm... "rephrase" ;-)
>
>
>according to the sql doc that came with the ib 6 beta doc from
>Borland, the default isolation is "snapshot"
>
>Is there a way to change the default isolation level, or is this
>simply done with the SET TRANSACTION option on a per session basis?

It is set on a per transaction basis.

>What are the dis-/advantages with doing so?

It's not a case of advantage/disadvantage. Sometimes you want
ReadCommitted, sometimes you want Snapshot. As a general rule, use
Snapshot for transactions that need a stable view of data from beginning to
end - such as one querying data for a report or for data export, pumping,
etc. Use ReadCommitted when you have a high throughput of interactive work
and it's important for users to maintain a fresh view of others' changes.

There are a couple of TechInfo sheets at the IB objects site containing
discussions of the comparative uses of the various transaction isolations
and lock behaviours - http://www.ibobjects.com/TechInfo.html

Helen


All for Open and Open for All
Firebird Open SQL Database · http://firebirdsql.org ·
http://users.tpg.com.au/helebor/
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