Re: ms accuracy from Oracle

mlarson (mdlarson_at_brain.uccs.edu) wrote:

: dbms_utility.get_time
: It gives the time in hundredths of a second
:   I would like to do some benchmarks on SQL statements using
:   millisecond
:   precision, any ideas?

It's kind of interesting that people wish this granularity for any reason, as there are any number of factors that could make the results somewhat less than meaningful unless you do certain actions between runs.

• A database is generally multi-user, so the actions of others could affect the results;
• A machine is generally multi-user (W95 <snigger>), so the actions of other could affect the results;
• A machine is generally multi-process (W95 <snigger>), so the actions of other processes could affect the results;
• If you are accessing via a network - nuff said;
• V7 of Oracle has many of it's own features that could affect the results - sga, hogging rollback, locking, flushing to disk (affects system performance), cached SQL, etc, etc.

I suspect that if you require millisecond precision for SQL then maybe you a) have no problem in the first place and 2) are doing the wrong sort of

   test - maybe many 1000's of itterations would be a better bet to reduce    some of the previously mentioned problems.

Just my 0.02.

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