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Posted to users@jena.apache.org by Wei Zhang <we...@adelaide.edu.au> on 2014/08/11 08:47:20 UTC
Does the TDB optimizer level "ALL" provide record accesses in every
query?
Hello All,
I am new here and want to find out if TDB is useful for my work.
But first I need to know that if the TDB optimizer level "ALL" provide record accesses in every query, then decide if I need to install it...
Could anyone kindly help on my naïve question?
Thank you very much for your help!
The level are explained here (https://jena.apache.org/documentation/tdb/optimizer.html) says "...every database access".
Level
Effect
INFO
Log each query
FINE
Log each query and it's algebra form after optimization
ALL
Log query, algebra and every database access (can be expensive)
NONE
No information logged
Best Regards,
Wei Zhang
Re: Does the TDB optimizer level "ALL" provide record accesses in
every query?
Posted by Wei Zhang <we...@adelaide.edu.au>.
Hi Andy,
Thank you very much! I want to get the record access and do some research on about caching on TDB.
You are right! I need to try it out and see if it can work.
Best regards,
Wei
On 2014-8-11, at 下午7:20, "Andy Seaborne" <an...@apache.org> wrote:
> Hi there,
>
> Yes - it should log on every query and indicate every database access (i.e. the execution of a basic graph pattern). It can be set per-query or globally. Don't forget to make sure the log4j logging is enabled as well.
>
> Probably the best way to know exactly what it does is to try it out or look at the code.
>
> Look at OpExecutorTDB1.
>
> What are you trying to achieve?
>
> Andy
>
>
> On 11/08/14 07:47, Wei Zhang wrote:
>> Hello All,
>>
>> I am new here and want to find out if TDB is useful for my work.
>> But first I need to know that if the TDB optimizer level "ALL" provide record accesses in every query, then decide if I need to install it...
>> Could anyone kindly help on my naïve question?
>>
>> Thank you very much for your help!
>>
>> The level are explained here (https://jena.apache.org/documentation/tdb/optimizer.html) says "...every database access".
>>
>> Level
>>
>> Effect
>>
>> INFO
>>
>> Log each query
>>
>> FINE
>>
>> Log each query and it's algebra form after optimization
>>
>> ALL
>>
>> Log query, algebra and every database access (can be expensive)
>>
>> NONE
>>
>> No information logged
>>
>>
>>
>> Best Regards,
>> Wei Zhang
>
Re: Does the TDB optimizer level "ALL" provide record accesses in
every query?
Posted by Andy Seaborne <an...@apache.org>.
Hi there,
Yes - it should log on every query and indicate every database access
(i.e. the execution of a basic graph pattern). It can be set per-query
or globally. Don't forget to make sure the log4j logging is enabled as
well.
Probably the best way to know exactly what it does is to try it out or
look at the code.
Look at OpExecutorTDB1.
What are you trying to achieve?
Andy
On 11/08/14 07:47, Wei Zhang wrote:
> Hello All,
>
> I am new here and want to find out if TDB is useful for my work.
> But first I need to know that if the TDB optimizer level "ALL" provide record accesses in every query, then decide if I need to install it...
> Could anyone kindly help on my naïve question?
>
> Thank you very much for your help!
>
> The level are explained here (https://jena.apache.org/documentation/tdb/optimizer.html) says "...every database access".
>
> Level
>
> Effect
>
> INFO
>
> Log each query
>
> FINE
>
> Log each query and it's algebra form after optimization
>
> ALL
>
> Log query, algebra and every database access (can be expensive)
>
> NONE
>
> No information logged
>
>
>
> Best Regards,
> Wei Zhang
>
>