how to control RAM limit on kdb application

Hi,We have a situation where we need to control the hard limit on totalRAM kdb can consume per physical machine. Let’s say that memory limitis 30G. What do we need to do to ensure kdb on that box do not usemore than 30G RAM? Is splayed tables our only choice? If it is, howdo we control it so it does use more than 30G?Another way to ask this question is to compare with a relationaldatabase such as Oracle. Oracle DBA can set RAM limit allocated foreach Oracle instance and it’s the database’s job to manage dataswapping between in-memory and disk.Can someone please help answer this question? We need answer to thisvery urgently. Thank you.

I am assuming you are a commercial user, and would therefore be welcome on the commercial users mailing list. This mailing group is for the non-commercial version which is limited to 32bit.

You can limit how much memory a single kdb+ process can consume via the -w command line option.

If you need to reduce the RAM used by a process, you need to reduce the amount of data that you have loaded in RAM; moving data from RAM to disk with splayed tables sounds like a reasonable option.

Sure. Does “-w” control RAM size for each kdb process or all kdbinstances on the same machine, including gateways? Thank you.On Aug 6, 2:48?pm, Charles Skelton <char…> wrote:> I am assuming you are a commercial user, and would therefore be welcome on> the commercial users mailing list. This mailing group is for the> non-commercial version which is limited to 32bit.>> You can limit how much memory a single kdb+ process can consume via the -w> command line option.>> If you need to reduce the RAM used by a process, you need to reduce the> amount of data that you have loaded in RAM; moving data from RAM to disk> with splayed tables sounds like a reasonable option.>> On Fri, Aug 6, 2010 at 8:31 PM, Jack <monkeylit…> wrote:> > Hi,>> > We have a situation where we need to control the hard limit on total> > RAM kdb can consume per physical machine. ?Let’s say that memory limit> > is 30G. ?What do we need to do to ensure kdb on that box do not use> > more than 30G RAM? ?Is splayed tables our only choice? ?If it is, how> > do we control it so it does use more than 30G?>> > Another way to ask this question is to compare with a relational> > database such as Oracle. ?Oracle DBA can set RAM limit allocated for> > each Oracle instance and it’s the database’s job to manage data> > swapping between in-memory and disk.>> > Can someone please help answer this question? ?We need answer to this> > very urgently. ?Thank you.>> > –> >

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each process

-w controls both kdb exec engine and gateway? Thanks.On Aug 6, 3:13?pm, Charles Skelton <char…> wrote:> each process>> On Fri, Aug 6, 2010 at 9:10 PM, Jack <monkeylit…> wrote:> > Sure. ?Does “-w” control RAM size for each kdb process or all kdb> > instances ?on the same machine, including gateways? ?Thank you.>> > On Aug 6, 2:48 pm, Charles Skelton <char…> wrote:> > > I am assuming you are a commercial user, and would therefore be welcome> > on> > > the commercial users mailing list. This mailing group is for the> > > non-commercial version which is limited to 32bit.>> > > You can limit how much memory a single kdb+ process can consume via the> > -w> > > command line option.>> > > If you need to reduce the RAM used by a process, you need to reduce the> > > amount of data that you have loaded in RAM; moving data from RAM to disk> > > with splayed tables sounds like a reasonable option.>> > > On Fri, Aug 6, 2010 at 8:31 PM, Jack <monkeylit…> wrote:> > > > Hi,>> > > > We have a situation where we need to control the hard limit on total> > > > RAM kdb can consume per physical machine. ?Let’s say that memory limit> > > > is 30G. ?What do we need to do to ensure kdb on that box do not use> > > > more than 30G RAM? ?Is splayed tables our only choice? ?If it is, how> > > > do we control it so it does use more than 30G?>> > > > Another way to ask this question is to compare with a relational> > > > database such as Oracle. ?Oracle DBA can set RAM limit allocated for> > > > each Oracle instance and it’s the database’s job to manage data> > > > swapping between in-memory and disk.>> > > > Can someone please help answer this question? ?We need answer to this> > > > very urgently. ?Thank you.>> > > > –> > > > You received this message because you are subscribed to the Google> > Groups> > > > “Kdb+ Personal Developers” group.> > > > To post to this group, send email to personal-kdbplus@googlegroups.com> > .> > > > To unsubscribe from this group, send email to> > > > personal-kdbplus+unsubscribe@googlegroups.com> > >> > > > .> > > > For more options, visit this group at> > > >http://groups.google.com/group/personal-kdbplus?hl=en.&gt;&gt; > –> >

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