Hi Lex, If Oracle determines that if a block will be accessed multiple times by the _same_ SQL, then it moves it to PGA. If the same can be accessed multiple times by _different_ SQL statements it ends up in SGA? Is there a cut off number for accessing the data block above which Oracle places it to PGA? Thanks. On 8/4/05, Lex de Haan <lex.de.haan@xxxxxxxxxxxxxx> wrote: > a BUFFER SORT typically means that Oracle reads data blocks into private > memory, > because the block will be accessed multiple times in the context of the SQL > statement execution. in other words, Oracle sacrifies some extra memory to > reduce the overhead of accessing blocks multiple times in shared memory. this > has nothing to do with sorting ... > > additions/corrections welcome, > kind regards, > > Lex. > > ------------------------------------------------------------------ > Steve Adams Seminar http://www.naturaljoin.nl/events/seminars.html > ------------------------------------------------------------------ > > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On > Behalf Of Deepak Sharma > Sent: Wednesday, August 03, 2005 23:31 > To: oracle-l@xxxxxxxxxxxxx > Subject: Buffer Sort explanation > > What does the 'BUFFER SORT' step mean and how does it get calculated, say in > below example? It is out of a tkprof output of a star transformation query. > > 105 BITMAP MERGE > 351549 BITMAP KEY ITERATION > 127009880 BUFFER SORT > 1607720 TABLE ACCESS FULL SYS_TEMP_4254956840 > 351549 BITMAP INDEX RANGE SCAN OBJ#(3441108) > PARTITION: 1 177 (object id 3441108) > -- Thanks, Ram. -- //www.freelists.org/webpage/oracle-l