| Subject | Re: [firebird-support] Re: Query never return |
|---|---|
| Author | Helen Borrie |
| Post date | 2009-06-22T00:16:32Z |
At 07:11 AM 22/06/2009, svanderclock wrote:
I suspect you are confusing this with an optional parameter of the DPB call that overrides the default buffer size for a single database session. Before v.2.1.2 you could do it. From v.2.1.2, it is very restricted (read the release notes). But this function call does *not* write anything to the database header and it does not change anything in firebird.conf.
This value is written at database creation time. It can be changed using gfix with the -b switch. You can also change it when restoring a database, using the -p[age_size] parameter.
./heLen
>--- In firebird-support@yahoogroups.com, Dmitry Yemanov <dimitr@...> wrote:Setting that value to 0 does not disconnect a database. You set it using gfix -b and you can't do it unless you are SYSDBA and have exclusive access to the database.
>>
>> svanderclock wrote:
>> >
>> > Database header page information:
>> > Page size 4096
>> > Page buffers 10240
>>
>> 40MB per connection? And 200 concurrent connections? It's not a surprise
>> that you go out of memory.
>>
>>
>> Dmitry
>>
>
>sh..t ! i was thinging that Page buffer 10240 was only for the super server ... not for the classic server :( also i m sure that i set in the database lot of time ago this value to 0 (to disconnect it) so i can not understand why it's come back to 10240 :(
I suspect you are confusing this with an optional parameter of the DPB call that overrides the default buffer size for a single database session. Before v.2.1.2 you could do it. From v.2.1.2, it is very restricted (read the release notes). But this function call does *not* write anything to the database header and it does not change anything in firebird.conf.
>so what the difference (or what the purpose) of these 3 values :It is the size of one database page, in bytes.
>page size,
>page buffers,It is returned by gstat -h and reports the value in the database header of the configured number of database pages that are allocated for the cache for this database. If it is non-zero, it overrides the server-wide setting, and has been configured deliberately. (By default, databases are created with 0 page buffers).
This value is written at database creation time. It can be changed using gfix with the -b switch. You can also change it when restoring a database, using the -p[age_size] parameter.
>DefaultDbCachePages ?It is the server-wide setting for the number of database pages to be allocated for the caches for **all databases on this server**. It will be used only for databases that have zero (page) buffers configured in the database header.
./heLen