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Former Member

Sequential /random disk read and write %

Dear Experts ,

can some one guide me from where i can find the exact values over a period of months for sequential/random disk (Input/ouput) reads and writes , i have searched on st03n >> workload >> database there i can see no of sequential read and direct access , i could sum up these values and get the required values for read at least but when i compare them to the data i get from st04 it somehow does not match

for st04 i can see much more number of physical reads ,i am assuming the sum of sequential reads and #accesses from st03n should sum up to the physical read field from st04

can anyone please support

Best Regards,

Shubham Jain

st03n.PNG (6.8 kB)
st04.PNG (12.1 kB)
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1 Answer

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    Former Member
    Jan 13, 2016 at 03:00 PM

    you can get the historical data in ST03 -> change mode to Expert mode --> workload --> total. Here you can see the data by Day/Week/Month.

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    • Former Member Former Member

      hi,

      you are confusing "things"

      When SAP (SM50 or SM66, for example) you see the term "sequential read" that is different from Oracle "db file sequential read"

      the first only indicates that the source code NOT requesting one row (SELECT SINGLE, SELECT UP TO 1 ROW or a SELECT specifiying all primary key fields with an equal)

      The second indicates that ONE block has been requested to the disk.

      The first does not indicate anything related to disk I/O, the second does not includes all disk I/O (direct reads, db file multiblock read ...)