Guidance on ipcshm v. ipcstr

I am running UnixWare 7.1.1 with IDS 7.3.1.UD5. I am not understanding from the docs I am reading when one is prefered over the other. Are there any guidlines to making the decision of using shared memory v. steam pipes for local connections? Thanks Tim Bragg.

Tim Bragg wrote: >I am running UnixWare 7.1.1 with IDS 7.3.1.UD5. > >I am not understanding from the docs I am reading when one is prefered >over the other. Are there any guidlines to making the decision of using >shared memory v. steam pipes for local connections? > >Thanks Tim Bragg. > > > > For best performance you should use SHM. But performance of STR is very close to SHM. From my experience < 10% slower. Another thing to think about is: If you choose SHM, you access the database memory for r/w. Illegal memory accesses from your application may corrupt the informix mem. Regards Frank

----LNX_Fri_Mar_14_2003_08:54:28_V3.33-- Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable >Datum: 2003.03.13 18:00:53 >Sender: Tim Bragg <BRAGGTIM@pentamation.com> > >I am not understanding from the docs I am reading when one is prefered >over the other. Are there any guidlines to making the decision of using >shared memory v. steam pipes for local connections? = If one process needs multiple connections to the same instance you must use stream pipes (not supported with shared memory connections). = If not I would prefer shared memory (a little bit faster, less problems after IDS crash - if using stream pipes it might be necessary to delete sockets in /INFORMIXTMP manually). = Regards, Andreas Kutsche = ------------------------------------------------ SPAR Oesterreichische Warenhandels-AG Hauptzentrale Europastra=DFe 3 A-5015 Salzburg = Telefon : +43 662 4470 24423 E-Mail : Andreas.KUTSCHE@spar.at Internet: http://www.spar.at ------------------------------------------------ = ----LNX_Fri_Mar_14_2003_08:54:28_V3.33----

In message <200303131429.JAA21169@ace.iiug.org>, Tim Bragg <BRAGGTIM@pentamation.com> writes >I am running UnixWare 7.1.1 with IDS 7.3.1.UD5. > >I am not understanding from the docs I am reading when one is prefered >over the other. Are there any guidlines to making the decision of using >shared memory v. steam pipes for local connections? > >Thanks Tim Bragg. > In addition to the information offered by other responders, I have almost always found that the performance of shared memory is better than streams, although I dimly recall the opposite being true for one particular machine/OS/version combination. Try it with your application... -- Andrew Lennard andy@kontron.demon.co.uk

One more reason for using streams over shared memory - you can't do distributed database over a shared memory connection. connect to 'stores@anubis_97'; select * from unlogged@anubis_53_shm:systables; Certainly, 9.30 fails... -- Jonathan Leffler (jleffler@us.ibm.com) STSM, Informix Database Engineering, IBM Data Management Solutions 4100 Bohannon Drive, Menlo Park, CA 94025 Tel: +1 650-926-6921 Tie-Line: 630-6921 "I don't suffer from insanity; I enjoy every minute of it!" |---------+----------------------------> | | "Andy Lennard " | | | <andy@kontron.dem| | | on.co.uk> | | | Sent by: | | | forum.subscriber@| | | iiug.org | | | | | | | | | 03/17/2003 02:56 | | | AM | | | | |---------+----------------------------> >------------------------------------------------------------------------------- --------------------------------------------------------------| | | | To: ids@iiug.org | | cc: | | Subject: Re: Guidance on ipcshm v. ipcstr [733] | | | >------------------------------------------------------------------------------- --------------------------------------------------------------| In message <200303131429.JAA21169@ace.iiug.org>, Tim Bragg <BRAGGTIM@pentamation.com> writes >I am running UnixWare 7.1.1 with IDS 7.3.1.UD5. > >I am not understanding from the docs I am reading when one is prefered >over the other. Are there any guidlines to making the decision of using >shared memory v. steam pipes for local connections? > >Thanks Tim Bragg. > In addition to the information offered by other responders, I have almost always found that the performance of shared memory is better than streams, although I dimly recall the opposite being true for one particular machine/OS/version combination. Try it with your application... -- Andrew Lennard andy@kontron.demon.co.uk