On Sun, Jun 08, 2008 at 11:38:12PM +0200, Martin Kersten wrote: > Rt Ibmer wrote: > > > Hi - how can I tell how much disk storage space on of my tables is using? > > > > I tried one rough way but not sure if it is accurate. Basically I did a > > linux du command > this is the correct way until a fullfledged DBA tool is available or the > necessary functions are packaged in a SQL module. > > and looked at the farmdb dir root, then imported about 2M rows, then looked > > a tthe du number again. But it only went up about 1.5MB for 2M rows of > > data? > > > bytes or blocks
MB = Megabytes = 1024 bytes. but: don't forget about the logs in .../sql-logs (next to .../dbfarm)/ MonetDB/SQL uses write-ahead-logging, i.e., until the logs are flushed (due to a server restart or after some time (AFAIK ca. 5 min right now) changes are kept in the WAL (here: sql-logs), before they are physically applied to the DBfarm. Stefan > > There are about 150 columns but only about 30-40 columns for any given row > > are populated. Certainly this would be fantastic if the compression is > > really this good! Seems possible, but I wasn't sure if this technique was > > accurate and if there was a better way. > > > compression is not applied beyond ordinary byte alignments > > Also on a related note - is there any detailed information on what types > > of compression and encoding MonetDB uses. For instance does it use Run > > Length Encoding or deltas or other such methods? > > > none > > And are there query plans / optimizers of any sort that you can feed > > MonetDB and it will optimize the layout or create internal subtables to > > help speed the types of queries we will be making? > > > MonetDB is targeted as a self organizing system. You can not even > control the creation of indices > and some recent additions (not in the to be released version) make > common subexpression > elimination automatic over long query sequences and at any level of > profitability. > > Thank you! -- | Dr. Stefan Manegold | mailto:[EMAIL PROTECTED] | | CWI, P.O.Box 94079 | http://www.cwi.nl/~manegold/ | | 1090 GB Amsterdam | Tel.: +31 (20) 592-4212 | | The Netherlands | Fax : +31 (20) 592-4312 | ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Monetdb-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/monetdb-developers
