big difference for the query time cost

[xixi]

hi,

we are using db2 udb v8.1 on win 64 bit with fp3 with type 4
db2jcc.jar driver.
i have a query, if using control center explain sql tool, i get the
access path graph with total cost 0.26. but if i use type 4 jcc jdbc
driver to execute the query, it takes 16 milliseconds. why there is so
big performance difference? is this driver issue? please help. thanks

[PM \(pm3iinc-nospam\)]

Access paths are generally expressed as timeron units, not ms.

PM

"xixi" <da****@yahoo.com> a écrit dans le message de
news:c0**************************@posting.google.c om...

hi,

we are using db2 udb v8.1 on win 64 bit with fp3 with type 4
db2jcc.jar driver.
i have a query, if using control center explain sql tool, i get the
access path graph with total cost 0.26. but if i use type 4 jcc jdbc
driver to execute the query, it takes 16 milliseconds. why there is so
big performance difference? is this driver issue? please help. thanks

[xixi]

so in other words, that is how many milliseconds? thanks

[Serge Rielau]

xixi wrote:

so in other words, that is how many milliseconds? thanks

It's not a direct correlation timerons are a magic mix of resource
consumtion. It may for example involve estimates sort-memory
consuptions, I/O, CPU utilization, etc...

Cheers
Serge

--
Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab