Data loads: Offline performance with online benefits

[simon]

Hi
Hopefully someone could point me in the right direction on this one.

INFRASTRUCTURE
DB2 v7 on MVS OS390

SCENARIO
We are currently loading large volumes of data (eg 20MM rows) per day
into a partitioned DB2 database. In the installed version of DB2
there are only upto 240 (or so) partitions, so we have to double up
and put two days (eg Day 34 and Day 276) in each partition.
The problem occurs when we need to load new data into a given
partition (ie replacing Day 34) whilst allow the other day's data to
be readable (ie Day 276).
This is currently being done using an online load which works fine
except from the cpu and elapsed timeframes.

SOLUTION
1. In version 8, this problem goes away since we can use upto 2040
partitions (ie one or two per day) but the rollout plan for this isn't
for another year or so.
2. I've heard about shadow or flip/flop tables whereby the old data is
kept online whilst a copy of it is amended before the view (or
whatever) is updated to view this new data. Is there any sort of DB2
command or url I can use/view which demonstrates this ??

Thanks for any help in advance.
Simon.

[Mark A]

"simon" <si******@hotmail.com> wrote in message
news:3e*************************@posting.google.co m...

Hi
Hopefully someone could point me in the right direction on this one.

INFRASTRUCTURE
DB2 v7 on MVS OS390

SCENARIO
We are currently loading large volumes of data (eg 20MM rows) per day
into a partitioned DB2 database. In the installed version of DB2
there are only upto 240 (or so) partitions, so we have to double up
and put two days (eg Day 34 and Day 276) in each partition.
The problem occurs when we need to load new data into a given
partition (ie replacing Day 34) whilst allow the other day's data to
be readable (ie Day 276).
This is currently being done using an online load which works fine
except from the cpu and elapsed timeframes.

SOLUTION
1. In version 8, this problem goes away since we can use upto 2040
partitions (ie one or two per day) but the rollout plan for this isn't
for another year or so.
2. I've heard about shadow or flip/flop tables whereby the old data is
kept online whilst a copy of it is amended before the view (or
whatever) is updated to view this new data. Is there any sort of DB2
command or url I can use/view which demonstrates this ??

Thanks for any help in advance.
Simon.

I think you mean that you have a partitioned tablespace(s), not database.

The flip flop technique is used by DB2 for on-line reorgs. I am not sure if
it only applies to one partition in a partitioned tablespace. You could look
at the technique employed by DB2 to do that, but I think they do it at the
VSAM level.

You could use rename table SQL to flip-flop tables, but I believe it applies
to the whole table and not just a partition (which still might be OK).