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Re: Hints to speed-up select into statement

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Hi Mike,

 

Thank you for your feedback.

 

I did the test by

1. try to clear the data cache, to do so I did several 'select count(*) from xxx' on other big tables to make sure TABLE_A was not in the cache. So far only 452Kb was reported in the cache (select CachedKB from monCachedObject where ObjectName='TABLE_A'

 

2.set statistics timo, io on

 

3. execute select count(*) from TABLE_A

 

1> select count(*) from TABLE_A

2> go

Parse and Compile Time 0.

Adaptive Server cpu time: 0 ms.

Parse and Compile Time 0.

Adaptive Server cpu time: 0 ms.

           

-----------

    17244487

Table: TABLE_A scan count 1, logical reads: (regular=37521 apf=0 total=37521), physical reads: (regular=8 apf=4714 total=4722), apf IOs used=4714

Total writes for this command: 0

 

Execution Time 37.

Adaptive Server cpu time: 3700 ms.  Adaptive Server elapsed time: 122120 ms.

 

 

(1 row affected)

 

Unless mistaken, the time to execute 1 IO is: (122120-3700)/4722 = 25ms

 

so 25ms for 1 IO seems very slow for me. Am I right?

 

Thanks

 

 

Simon


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