[EMAIL PROTECTED] wrote: > > > Hi, > > We are working with our newly aquired 8GB Sun Solaris Sparc > system. We figured once the DATA_CACHE was populated that > most of our > SELECT statements would scream... as we are only working with > 10GB of data... > > Solaris shows that disk writes are being performed during our > SELECT statements, even when it appears all the data is in > MaxDB cache. I can > only suspect this is Temporary Table activity? > > Is there any way to hint to MaxDB to use RAM for Temporary > Tables? Any tricks to suggest? This is a read-only database > that will be used > for data analysis... any and all tips on getting MaxDB to use > that RAM to best advantage are appreciated. > > Thank you. > > Stephen Gutknecht > > You did not tell us the size of your DATA_CACHE and you did not tell us something about your selects.
The (intermediate) result of selects are stored in the data cache and they can be very huge, no matter of the size of the data used. If, for example, a cartesian product (every row of one table joined with every row of another one) is done for three tables, the final result may be small, but the intermediate result may be huge --> needing I/O. You did not tell us if we are talking about a single-user-system or something, were 50 users in parallel are preparing select-results, each single one fitting in your cache, but not fitting all together. You did not tell us, if ths 10GB of data means the primary data of all tables or the primary data plus the indexes. There is no chance and no need to TELL the system to use the RAM. If there was enough there for the needs, it would do it by its own. But for some (so far unknown) reason your calculation of the needs and the systems needs differ. Elke SAP Labs Berlin > > > -- > MaxDB Discussion Mailing List > For list archives: http://lists.mysql.com/maxdb > To unsubscribe: > http://lists.mysql.com/[EMAIL PROTECTED] > -- MaxDB Discussion Mailing List For list archives: http://lists.mysql.com/maxdb To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
