At 10:11 AM 5/02/2010, you wrote:

>As far as I am aware, if I choose
>ReadOnly with Isolation Committed (Read Committed)
>in the IB_Transaction properties, I have selected the non blocking, least impact (as far as garbage collection impact is concerned) transaction setting.
>I obviously don't need to write anything but I want this transaction to be longer than other transactions but I do not want it to hold back the transaction advancement.
>IBO says (Table Locking!!!) and (No Rec Version !!!!) as warnigns on the other isolation levels.
>
>So - assuming this is correct, what does this translate to in TPB settings?
>isc_tpb_read, isc_tpb_consistency ?

That is totally blocking. Never use it unless you absolutely want to exclude writers.

>or isc_tpb_read, isc_tpb_read_committed?

Yes. And make sure that neither ServerAutoCommit nor Autocommit is enabled in the IB_Transaction if you're using Fb 2.0.x up to and including 2.0.3, or Fb 1.5.3 or lower. (Some bad logic there could cause the r/o r/c transaction to drop out of the chain, and crash the server.).

Helen