Re: db_file_multiblock_read_count + db file scattered read + truss

Purely a guess, but looking at the figures do you think that Oracle is using readv for values up to 128K, and pread for values
larger than 128K ?

Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

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The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

• Original Message -----
  > 20 WAIT #3: nam='db file scattered read' ela= 3 p1=10 p2=2370
  p3=128
  > 21 WAIT #3: nam='db file scattered read' ela= 2 p1=10 p2=2498
  p3=68
  > 22 WAIT #3: nam='db file scattered read' ela= 1 p1=10 p2=2567
  p3=13
  > 23 WAIT #3: nam='db file scattered read' ela= 0 p1=10 p2=2581
  p3=9
  > 24 WAIT #3: nam='db file scattered read' ela= 0 p1=10 p2=2591
  p3=26

> 20 pread64(409, "0602\0\00280\t BDEF5 6E2".., 1048576,
0x01284000) = 1048576
> 21 pread64(409, "0602\0\00280\tC2DEF5 6E2".., 557056,
0x01384000) = 557056
> 22 readv(409, 0xFFBE927C, 13) = 106496
> 23 readv(409, 0xFFBE927C, 9) = 73728
> 24 pread64(409, "0602\0\00280\n1FDEF5 6E2".., 212992,
0x0143E000) = 212992

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jonathan Lewis
  INET: jonathan_at_jlcomp.demon.co.uk

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