[Info-Ingres] non blocking sysmod

[Karl & Betty Schendel]

At 5:19 PM +0100 4/17/07, Gibson Jonathan wrote:
>How are you supposed to do a sysmod in a high availability production
>system then?  We've always struggled to get a sysmod but occasionally
>we're lucky and one runs through now and again.

The theory behind the (then-)proposed implementation was that
while you couldn't have any transactions open, you COULD
have idle sessions attached while the nonblocking sysmod ran.
If any of them tried to do anything, they would simply stall
until the core catalog portion of the sysmod had completed.

Until this or some better scheme is implemented, the best you
can do is wait for a scheduled maintenance window.
(Or do like Marty and wait for, uh, unscheduled maintenance
windows.)

Karl