In  IMAGE, we have the concept of dynamic transactions, which are
covered by MPE's transaction manager (XM). Now XM stores information
about database modifications in a log file which has a definitie size.
If there are lot of simultaneous open transactions from the same sor
multiple sessions, all wiil get logged to the same XM log file, an the
same may gets filled up. The stalled transaction error will occur when
XM is not able to put in any more records into the log. In such a
situation, IMAGE will do an automatic rollback of  all the transactions
and leave the database in a consistent state.

When used with ISQL, the IMAGE/SQL front-end forces all transaction to
be dynamic transactions (i.e. start with DBXBEGIN and end with DBXEND).
This is due to the fact that in the SQL environment one may be able to
rollback the transactions at any time. So the individual transactions
(PUT, DELETE, UPDATE) will be kept open till the user gives a commit or
rollback. Thus may end up with the situation as above. However, when
using QUERY, it will not force any dynamic transaction to be opened, and
will not hit the XM log limit.

A solution to this is coming out with the coming MPEi/X version 6.5
release, where the log size can be configured to higher values.

Hope this clarifies

Regards,
Vikram

Bob Walker wrote:

> I'm trying to delete all entries from an Image set via ISQL and am
> getting the following error.
>
> isql=> delete from namedb.names;
> **** STALLED TRANSACTION: EXCEEDED ACCUMULATED LOG
> DATA THRESHOLD
> ABORT: ISQL.PUB.SYS
> NM SYS   a.00aa1288 dbg_abort_trace+$24
> NM PUB   26d.008672f0 m_ma:marspa+$4dc
> NM PROG  5e5.0005fc54 PROGRAM+$4344
>
> Info: HP3000-939 MPE 5.5 Express 7
> 2 log file for the DBE total 30000 pages.
> (isql=> checkpoint;
> Number of free log blocks is 29922)
>
> Data set is an Image Master(all dependencies have been deleted
> and I can successfully delete all entries from Query)
> and has ~2500 360-byte records.
>
> I can delete 1000 rows at a time from ISQL, but get the above error
> at about 1200 rows.
>
> Any ideas??
>
> thanks, Bob.
>
> --=--=--
> Bob Walker, Computer Centre  --  [log in to unmask]
> Capilano College, North Vancouver, BC, CANADA.
> ------
> 'No one is listening until you make a mistake.'