Hi,

There is not just one cache. It's in another cache, the "queryCache", not
the regular row cache. See
http://h2database.com/javadoc/org/h2/constant/DbSettings.html?highlight=queryCacheSize&search=queryCache#QUERY_CACHE_SIZE

However, I wonder what data is cached in the query cache. How large are
your query statements?

Regards,
Thomas





On Wed, May 8, 2013 at 5:34 PM, <[email protected]> wrote:

> I did so, but as i see it, that setting does not have any effect for in
> memory DBs as I use it.
>
>
>  *Cache Settings*
>
> The database keeps most frequently used data in the main memory. The
> amount of memory used for caching can be changed using the setting
> CACHE_SIZE. This setting can be set in the database connection URL (
> jdbc:h2:~/test;CACHE_SIZE=131072), or it can be changed at runtime using SET
> CACHE_SIZE size. The size of the cache, as represented by CACHE_SIZE is
> measured in KB, with each KB being 1024 bytes. *This setting has no
> effect for in-memory databases.* For persistent databases, the setting is
> stored in the database and re-used when the database is opened the next
> time. However, when opening an existing database, the cache size is set to
> at most half the amount of memory available for the virtual machine
> (Runtime.getRuntime().maxMemory()), even if the cache size setting stored
> in the database is larger; however the setting stored in the database is
> kept. Setting the cache size in the database URL or explicitly using SET
> CACHE_SIZE overrides this value (even if larger than the physical
> memory). To get the current used maximum cache size, use the query SELECT
> * FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME = 'info.CACHE_MAX_SIZE'
>
> An experimental scan-resistant cache algorithm "Two Queue" (2Q) is
> available. To enable it, append ;CACHE_TYPE=TQ to the database URL. The
> cache might not actually improve performance. If you plan to use it, please
> run your own test cases first.
>
> Also included is an experimental second level soft reference cache. Rows
> in this cache are only garbage collected on low memory. By default the
> second level cache is disabled. To enable it, use the prefix SOFT_.
> Example: jdbc:h2:~/test;CACHE_TYPE=SOFT_LRU. The cache might not actually
> improve performance. If you plan to use it, please run your own test cases
> first.
>
> To get information about page reads and writes, and the current caching
> algorithm in use, call SELECT * FROM INFORMATION_SCHEMA.SETTINGS. The
> number of pages read / written is listed.
>
>
>
>
> Regards,
>
> Christoff Schmitz
>
> F I N A R I S
> Financial Software Partner GmbH
> Sömmerringstrasse 23
> 60322 Frankfurt am Main
>
> Fon:      +49 (0)69  / 254 98 - 24
> Mobile: +49 (0)176 / 206 34 186
> Fax:       +49 (0)69  / 254 98 - 50
> eMail:    mailto:[email protected]<[email protected]>
> www:      http://www.finaris.de und http://www.rapidrep.com
>
>
>
> From:        Noel Grandin <[email protected]>
> To:        [email protected]
> Cc:        [email protected]
> Date:        08.05.2013 15:59
> Subject:        Re: Memory Usage Problem
> ------------------------------
>
>
>
> I could just tell you, but that would deprive you of discovering the
> excellent search feature on our website.
>
> On 2013-05-08 15:22, 
> *[email protected]*<[email protected]>wrote:
> Hi,
>
> I use H2 database as embedded database in memory.
> The queries processed by the database are quite large, as result  my
> memory profiler tells me that  the *queryCache *(Type *
> org.h2.util.SamllLRUCache*) member of an instance of *org.h2.engine.Session
> *consumes about 100 MB heap space.
>
> Is there a possibility to limit that cache size?
>
>
> Regards,
>
> Christoff Schmitz
>
> F I N A R I S
> Financial Software Partner GmbH
> Sömmerringstrasse 23
> 60322 Frankfurt am Main
>
> Fon:      +49 (0)69  / 254 98 - 24
> Mobile: +49 (0)176 / 206 34 186
> Fax:       +49 (0)69  / 254 98 - 50
> eMail:    *mailto:[email protected]*<[email protected]>
> www:      *http://www.finaris.de* <http://www.finaris.de/> und *
> http://www.rapidrep.com* <http://www.rapidrep.com/>
>
> =======================================================
> Disclaimer
> The information contained in this e - mail and any attachments
> ( together the "message") is intended for the addressee only and may
> contain confidential and/or privileged information. If you have received
> the message by mistake please delete it and notify the sender and do
> not copy or distribute it or disclose its contents to anyone.
>
> FINARIS Financial Software Partner GmbH
> Sömmerringstr. 23, 60322 Frankfurt/Main, Germany
> Registered at Frankfurt/Main, HRB 52873
>
> Managing Directors:
> Dipl. Inf. Hermann Friebel, Dipl. Ing. Kai Bächle, Dipl. Inf. Werner Märkl
> ======================================================= --
> You received this message because you are subscribed to the Google Groups
> "H2 Database" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to 
> *[email protected]*<[email protected]>
> .
> To post to this group, send email to 
> *[email protected]*<[email protected]>
> .
> Visit this group at 
> *http://groups.google.com/group/h2-database?hl=en*<http://groups.google.com/group/h2-database?hl=en>
> .
> For more options, visit 
> *https://groups.google.com/groups/opt_out*<https://groups.google.com/groups/opt_out>
> .
>
>
>
>
>
> =======================================================
> Disclaimer
> The information contained in this e - mail and any attachments
> ( together the "message") is intended for the addressee only and may
> contain confidential and/or privileged information. If you have received
> the message by mistake please delete it and notify the sender and do
> not copy or distribute it or disclose its contents to anyone.
>
> FINARIS Financial Software Partner GmbH
> Sömmerringstr. 23, 60322 Frankfurt/Main, Germany
> Registered at Frankfurt/Main, HRB 52873
>
> Managing Directors:
> Dipl. Inf. Hermann Friebel, Dipl. Ing. Kai Bächle, Dipl. Inf. Werner Märkl
> =======================================================
>
> --
> You received this message because you are subscribed to the Google Groups
> "H2 Database" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> To post to this group, send email to [email protected].
> Visit this group at http://groups.google.com/group/h2-database?hl=en.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>
>

-- 
You received this message because you are subscribed to the Google Groups "H2 
Database" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/h2-database?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.


Reply via email to