To whoever can assist,

I am working with a decent sized database on an extremely powerful machine. The specs follow:

        OS:                     RedHat Linux 9.0
        PG Version              7.3
        Memory          1 gig
        CPU                     Quad Processor - Unsure of exact CPUs
        Hard Drive              80 gigs
        Database Size           2 gigs

As you can see the server is built for overkill.

The problem that I see is as follows.

I do a rather simple query: select count (*) from large-table where column = some value;

About 80% of the time, the response time is sub-second. However, at 10% of the time, the response time is 5 - 10 seconds.

This is nothing readily apparent at the system level that comes close to explaining the performance hits. CPU and memory usage (as measured by top) appear to be fine.

Although there are certain tuning issues within the database itself, no documentation I have seen seems to indicate that tuning issues would lead to such inconsistent response time.

Any ideas?



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