Just for sure I tried it calling DmSyncDatabase before every DmCloseDatabase. As expected - no effect; DbCache remained constantly at the level of 1MB free space. This appears to be the limit when some cleanup takes place to create the space for the next cache request. However this cleanup just takes up lot of time without releasing more space.
Jan Slodicka ----- Original Message ----- From: "Hays, Jonathan (GE Infrastructure)" <[EMAIL PROTECTED]> To: "Palm Developer Forum" <[email protected]> Sent: Wednesday, March 02, 2005 6:50 PM Subject: RE: NVFS performace - purging DbCache Actually, the DmSyncDatabase just makes sure that the NVFS copy of the data is up to date. It doesn't empty or purge the DBCache. -Jon ------------------------------------------- Jonathan Hays Palm OS Certified Developer http://hazelware.luggle.com ------------------------------------------- -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Aaron Hansen Sent: Wednesday, March 02, 2005 8:59 AM To: Palm Developer Forum Subject: RE: NVFS performace - purging DbCache Hi Jan, There is a call to flush the DbCache for NVFS devices like the T5. The call is DmSyncDatabase. Here is a link to reference data on it: <http://www.palmos.com/dev/support/docs/palmos/PalmOSReference/DataAndRe sourceManager.html#1053148> Hope that helps you, Aaron Hansen >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of Jan Slodicka >Sent: Wednesday, March 02, 2005 9:20 AM >To: Palm Developer Forum >Subject: Re: NVFS performace - purging DbCache > > >Replying to myself... > >> It looks like the DmCloseDatabase writes back the DB header, >although >> I > >That's probably not the right idea because closing the >database happens always in exactly the same way, while the >speed loss is apparent only in case when DBCache is full. >It'll be rather that the T5 scans for free space in the >DBCache and because it is full, it takes so long. > >Not a very good message for T5 users as every one sooner or >later will fill up the DBCache. Isn't there any other way >except a reset? > >The deeper I understand T5, the more I like T3. > >Jan Slodicka > > >----- Original Message ----- >From: "Jan Slodicka" <[EMAIL PROTECTED]> >To: "Palm Developer Forum" <[email protected]> >Sent: Wednesday, March 02, 2005 2:57 PM >Subject: NVFS performace - purging DbCache > > >> Hello, >> >> there was enough discussion on NVFS so far, but (in my opinion) the >> following behavior was not explained: >> >> First the summary: >> After DBCache gets filled, the opening of the RAM databases >> dramatically slows down. >> >> Actually the sequence of the operations that slows down is >> DmOpenDBNoOverlay() with dmModeReadOnly >> DmCloseDatabase() >> (I eliminated all intermediate code for the test purposes so that it >> is >sure >> that exactly these commands are responsible for the effect.) >> >> It looks like the DmCloseDatabase writes back the DB header, >although >> I can't find any reason for it. >> >> Does anybody know a workaround? >> >> Best regards, >> Jan Slodicka > > >-- >For information on using the Palm Developer Forums, or to >unsubscribe, please see http://www.palmos.com/dev/support/forums/ > > -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/ -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/ -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
