Hi, we are currently looking for ways to reduce the overall memory usage when using Fastbit for longer running processes like this:
char *path; part *partition=0; table *tab=0; table *in_memory_select=0; table *select_on_select=0; partition=new part(path); tab=table::create(*partition); in_memory_select=tab->select(query1,where1); select_on_select=in_memory_select->select(query2,where2); delete select_on_select; delete in_memory_select; delete tab; delete partition; // program goes on after this but memory for tables is not yet fully freed! // following operations will take a long time to complete, thus the process is blocking memory for a long time... // an additional call to fileManager::instance().clear() would free the memory!! As far as I understand, all tables opened are memory mapped and registered in ibis::fileManager. It seems to me that deleting tables and partitions via operator delete does not immediately decrease the memory usage. I think they are still registered by the fileManager instance and will still allocate memory. The intention is probably to reuse the tables in other queries etc. A call to ibis::fileManager::clear() in addition to calling delete does seem to free all the memory. I have now few questions on this: - Is it safe to call ibis::fileManager::clear() even if there are still any open tables? Does the call to clear free all objects or just objects not opened/referenced anymore? - Is calling fileManager::clear() after operator delete the intended way to decrease memory usage or are there any better mechanisms? Thank you for info on this and best regards Jan -- Jan Steemann [email protected] Phone +49 2233 7933 752 | Fax +49 2233 7933 788 Globalpark AG | Kalscheurener Str. 19a | 50354 Huerth | Germany Vorsitzender des Vorstands/Chief Executive Officer (CEO) | Dr. Lorenz Graef Mitglieder des Vorstands/Board Member | Frank Kleinert, Frank Michael, Oliver Trabert Vorsitzender d. Aufsichtsrats/Chairperson of the Supervisory Board | Dr. Richard C. Geibel | HRG Amtsgericht Koeln/Entered on Cologne | Local Court Commercial Register | HRB 64032 GLOBALPARK - manage what matters | http://www.globalpark.de _______________________________________________ FastBit-users mailing list [email protected] https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
