John L. Singleton wrote: > > I found said formula here: > http://lists.mysql.com/maxdb/19208 > > "10.000 pages x 8 KB are about 80 MB and you need some shared > areas for > the libraries and for each connection. So 94 MB is exact the memory > that's expected. " > > This statement led me to believe "connection" = a user task.
The last sentence is true, but it is a misunderstanding that each connection needs these 80 MB > > "Each usertask needs _MAXTASK_STACK KB of memory. > The value for _MAXTASK_STACK depends on the operating system and the > version used (you are using 7.3, aren't you?). It varies > between 310 (7.3), > 400 (7.4) and 1024 KB." > > Could you direct me to where you found that information? > (assuming it's not from your head?) it is the minimum size of the installation parameter _MAXTASK_STACK. it can be seen during installation via DBMGUI and/or <installation_root>/env/cserv.pcf for your OS. > > So MAXUSERTASKS * _MAXTASK_STACK KB + 64 KB = consumed memory. 1. MAXUSERTASKS * ( _MAXTASK_STACK KB + 64 KB) = consumed memory for usertasks. 2. several other parts (Data cache, locklist, ...) need memory, the sizes are defined during database installation. Elke SAP Labs Berlin > Is there a breakdown of a usertask, in terms of > shared/virtual memory? Or rather, how much of a usertask is > implemented in shared memory? And how much in the virtual memory? > > As I understand it, local connections communicate through > IPC/SHM --- so I'd imagine it varies, depending on how the > connection originated? > > Thanks for your patience, > > JLS > > > > > > Zabach, Elke wrote: > > >John L. Singleton wrote: > > > > > >>Hello Everyone, > >> > >>I'm trying to come up with some sort of utilization formula > for user > >>tasks. I've seen at least three on this list---all of them > different. > >> > >>The ones I've seen: > >> > >>MAXUSERTASKS *310KB + some other stuff > >> > >> > > > >Each usertask needs _MAXTASK_STACK KB of memory. > >The value for _MAXTASK_STACK depends on the operating system and the > >version used (you are using 7.3, aren't you?). It varies > between 310 (7.3), > >400 (7.4) and 1024 KB. > > > >Additionally each usertask needs at least 64KB local cache. > > > > > > > >>MAXUSERTASKS * 10.000 pages * 8KB > >> > >> > > > >where does this come from? Was it a discussion about the > size of the data cache? > >I do not know such a value per user task. It may have been > an advice for a data cache > >with enough space for several parallel users. But it depends > on your database size, > >the table sizes usually used,.. > > > >Elke > >SAP Labs Berlin > > > > > >>Does anyone have the goods on this parameter? I'm interested in > >>determining two values: > >> 1> The amount of shared memory required per user task. > >>(ie, what to > >>set SHMMAX, etc. to) > >> 2> The amount of physical/virtual memory required, per > user task. > >> > >> > >>Thanks! > >>John L. Singleton > >> > >>-- > >>MaxDB Discussion Mailing List > >>For list archives: http://lists.mysql.com/maxdb > >>To unsubscribe: > >>http://lists.mysql.com/[EMAIL PROTECTED] > >> > >> > >> > > > > > > > -- MaxDB Discussion Mailing List For list archives: http://lists.mysql.com/maxdb To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
