Update/Load Slooooow

cbielins

Ok so I was using update to flip-flop some data in one of our fact
event tables. It was chugging OK, but I thought it could have been
faster. I ceased the update script and ran runstats on the table.
After it completed runstats, its updating even SLOWER!!!

Any thoughts?

Thanks,
Chris

Nov 12 '05 #1

Serge Rielau

cb******@gmail.com wrote:

Ok so I was using update to flip-flop some data in one of our fact
event tables. It was chugging OK, but I thought it could have been
faster. I ceased the update script and ran runstats on the table.
After it completed runstats, its updating even SLOWER!!!

Run explain and take a peek.

Cheers
Serge
--
Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab

Nov 12 '05 #2

cbielins

What exactly would be that syntax? I've never used 'explain' before.

Thanks,
+CB

Nov 12 '05 #3

Serge Rielau

cb******@gmail.com wrote:

What exactly would be that syntax? I've never used 'explain' before.

Thanks,
+CB

cd sqllib/misc
db2 -tvf EXPLAIN.DDL
db2 "explain plan for update ....."
db2exfmt -d <dbname> -o badupdate.exfmt -1 <- this is "minus one" not "L"

check out the badupdate.exfmt file.
(you can also post it here and hope someone comments)

How many idexes do you have on the table?
Keep in mind that adding indexes slows down changes to the table...

Cheers
Serge

PS: If you run a db warehouse explaining (and interpreting) plans is a
base skill.... google for "visual explain" and db2exmt. There are quite
a few resources available.....
--
Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab

Nov 12 '05 #4