bigbalbossa
Programmer
Is there a way to predict how long a piece of sql could run??? Seems like you could with Oracle...
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Can you predict sql runtime???
- Thread starter bigbalbossa
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gregsimpson
Programmer
- Apr 18, 2002
- 521
bigbalbossa,
you can use explain with db2, which will give you a theoretical time, in terms of timerons. This is simply a measure of how the DB2 optimiser has decided to go and get the data you are asking for and how it's going to do it. This can then allow you to further tune your SQL or add indexes etc.
On top of how many reads DB2 has to do you also need to take into account the speed of your disk controllers etc.
Greg
you can use explain with db2, which will give you a theoretical time, in terms of timerons. This is simply a measure of how the DB2 optimiser has decided to go and get the data you are asking for and how it's going to do it. This can then allow you to further tune your SQL or add indexes etc.
On top of how many reads DB2 has to do you also need to take into account the speed of your disk controllers etc.
Greg
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