On 02/18/12 21:27, Leyne, Sean wrote:
> Björn,
>
>> Executing a query with a little bit longer execution time I get negative
>> numbers for some values. Execution is done via IBExpert. Firebird ist 2.5.1
>> CS on Linux 64 bit Client Lib is 2.5.1 Windows 32 bit.
>>
>> Prepare time = 63ms
>> Execute time = 43h 53m 31s 63ms
>> Avg fetch time = 158.011.063,00 ms
>> Current memory = -507.368.239
>> Max memory = -466.997.327
>> Memory buffers = 20.480
>> Reads from disk to cache = 13.786.623
>> Writes from cache to disk = 290.317
>> Fetches from cache = -1.256.613.653
>>
>>
>> Is it a bug in IBExpert or does the overflow occur in Firebird itself?
> It is very likely that the engine/performance counter variables are SINT's,
> so they are overflowing/wrapping.
>
They were 32 bit integers, we have added duplicating API calls (like
perf_get_info => perf64_get_info) to make them be 64-bit in any (32/64)
type of API. ISQL is now using tthis new calls, looks like IBExpert is
using old API calls.
> Although, I have never personally understood what the memory variables
> represent, I wouldn't be surprised if the values were in bytes, not KB, so a
> query on a 64 bit server could easily use much more memory than the counter
> variable could store/represent.
>
>
> Sean
>
> P.S. A 43 hour query is impressive!!! (a _bit_ longer)!!! I'm not sure if
> that means that the query is running that long because of the amount of
> data/or the nature of the query, or if the query could be optimized. {That
> is the type of problem that I love to get my teeth into}
>
> P.P.S. Have you tried to increase your db cache size to see if the
> number of "reads from disk" would go down? (the current ratio of 100
> "fetches from cache"
It's also negative :-)
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