On Thu, Apr 28, 2016 at 2:16 PM, Gabor Boros gaborboros@... [firebird-support] <firebird-support@yahoogroups.com> wrote:

...

Try to utilize WITH LOCK because I need many unique number generators in
a table field. Like a generator/sequence but under transaction control.

Okay...  What's the requirement that keeps you from using generators?  Do you intend to grab the number in a transaction that does other work?  What is the concurrency requirement?  What you're thinking about doing will serialize the generation of identifiers and all other actions of those transactions.  I'm not totally convinced that using ReadCommitted/wait will create an auditable series of numbers in the case where a transaction fails. This article may give you a way to look at the problem.

http://www.ibobjects.com/TechInfo.html#ti_AuditableSeries

Good luck,

Ann