IDS Forum

Dropping distributions after upgrade

Posted By: John Bejarano
Date: Wednesday, 11 June 2003, at 5:35 p.m.

So, we're preparing to upgrade our HDR pair of
production databases from IDS version 7.31.UD1XF to
version 7.31.FD6, which by then will be running on
Solaris 8 64-bit. This upgrade is rising in priority
since we're starting to experience a bug whereby
indexes get corrupted on the secondary server.

The issue I'm most concerned with is that Informix
recommends dropping the distributions and re-creating
them after the upgrade. This database is over 450
gigabytes in size. Some tables have hundreds of
millions of rows, and many have over one million.

Not only am I concerned with the amount of time it
takes to actually re-create the statistics, (our
current update statistics cycle runs over 12 hours and
it uses 10 parallel update statistics processes to do
it), but also the amount of time to drop the
distributions in the first place as it must be done
using "update statistics low drop distributions," and
this fires off a giant index re-balancing. When we
did this similar procedure on our smaller 45 gigabyte
database it took several hours just to drop the
distrbitions because of this.

In addition, we can't upgrade on one box, and then
upgrade on the other because HDR requires the versions
on each side to be the same. And, we can't run the
update statistics on the secondary, because, well, you
can't.

This is our main production database, and I can't
bring it down for 12-36 hours as our company will be
out of business for that time. Nor would our website
be very useful if it's up but queries don't work for
hours and hours because there are no distributions.

Surely we can't be the only large production Informix
database that needs to upgrade our version once in a
while. How can we perform this upgrade in a sensible
way with as little downtime as possible? Or am I just
screwed?

Thanks for any insight you can lend.

Kind regards,

John Bejarano.

Messages In This Thread

• Dropping distributions after upgrade
  John Bejarano -- Wednesday, 11 June 2003, at 5:35 p.m.
  • Re: Dropping distributions after upgrade
    Obnoxio The Clown -- Thursday, 12 June 2003, at 2:36 a.m.
    • RE: Dropping distributions after upgrade
      Simmons, Keith -- Thursday, 12 June 2003, at 3:58 a.m.
    • RE: Dropping distributions after upgrade
      Obnoxio The Clown -- Thursday, 12 June 2003, at 12:51 p.m.
      • RE: Dropping distributions after upgrade
        Simmons, Keith -- Friday, 13 June 2003, at 4:24 a.m.
  • Re: Dropping distributions after upgrade
    John Bejarano -- Friday, 13 June 2003, at 9:03 p.m.
    • Re: Dropping distributions after upgrade
      Obnoxio The Clown -- Sunday, 15 June 2003, at 5:36 a.m.
      • Re: Dropping distributions after upgrade
        Mark Scranton -- Monday, 16 June 2003, at 11:31 a.m.
        • Re: Dropping distributions after upgrade
          John Bejarano -- Monday, 16 June 2003, at 2:18 p.m.
    • Fwd: Re: Dropping distributions after upgrade
      ART KAGEL, BLOOMBERG/ 65E 55TH -- Monday, 16 June 2003, at 8:40 a.m.

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