Hi list, I runt the following script to get the DB_FILE_MULTIBLOCK_READ_COUNT value SQL> ALTER SESSION SET DB_FILE_MULTIBLOCK_READ_COUNT =100; SQL> SET AUTOTRACE TRACEONLY SQL> ALTER SESSION SET TRACEFILE_IDENTIFIER='TEST_BLOCK_SIZE'; SQL> ALTER SESSION SET EVENTS '10046 TRACE NAME CONTEXT FOREVER, LEVEL SQL> SELECT /*+ FULL(A) */ * FROM ADM.TRANSAC_ME A; 371196 filas seleccionadas. Execution Plan ---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=206 Card=308952 Byte s=46342800) 1 0 TABLE ACCESS (FULL) OF 'TRANSAC_ME' (Cost=206 Card=308952 Bytes=46342800) Statistics ---------------------------------------------------------- 1118 recursive calls 0 db block gets 33023 consistent gets 8490 physical reads 60 redo size 31569813 bytes sent via SQL*Net to client 272709 bytes received via SQL*Net from client 24748 SQL*Net roundtrips to/from client 6 sorts (memory) 0 sorts (disk) But I get the different values in p3 WAIT #1: nam='db file scattered read' ela= 32568 p1=3 p2=51689 p3=8 WAIT #1: nam='db file scattered read' ela= 15915 p1=3 p2=51778 p3=7 WAIT #1: nam='db file scattered read' ela= 16483 p1=3 p2=51785 p3=8 WAIT #1: nam='db file scattered read' ela= 29985 p1=3 p2=51937 p3=8 WAIT #1: nam='db file scattered read' ela= 150 p1=3 p2=52050 p3=7 Any idea?, my ntfs disk is compressed. Juan Carlos Reyes Pacheco OCP ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------