How to check the instance datafile I/O? solve the high physical reads/writes?

Method-1
identify 'hot spots' or I/O contention
Select NAME,
"Physical reads," PHYRDS
round ((PHYRDS/PD.)) (PHYS_READS) * 100, 2) «Read %»,
PHYWRTS "physical Scriptures."
Round (PHYWRTS * 100/PD.) PHYS_WRTS, 2) "% of writing."
FS. PHYBLKRD + FS. PHYBLKWRT "Total block I / O of.
de)
Select sum (PHYRDS) PHYS_READS,
Sum (PHYWRTS) PHYS_WRTS
v $ filestat
) pd,.
v$ datafile df,.
v$ filestat fs
where df. FILE # = fs. FILE NO.
ranking by fs. PHYBLKRD + fs. PHYBLKWRT / / desc


Another method-
On Oracle10g, CWA also provides the dba_hist_filestatxs table to track the disk i/o:

break on begin_interval_time jump 2

column phyrds 999 999 999 format
column begin_interval_time format a25

Select
begin_interval_time,
file name,
phyrds
Of
dba_hist_filestatxs
natural join
dba_hist_snapshot;

It is - method that you use to check for errors in data I/O file? AND how to solve high physical reads and writes?

Ankit Ashok Aggarwal wrote:
AWR project stat e/s in terms of segments, query and etc.
Here, my concern is what should be the value of ideal threashold for a DBA to act on the high physical reads/writes?
and how he can fix this problem if it affects database performance?

I don't think that there is any possibility to mention that the amount of an e/s is going to be good or bad for a database in general. The reason is that it is not quantifiable. For example, in a store, maybe one day that no one gets and another day, there is no place to stand (because there was a sale announced by the store). So now, how do you say that it was not necessary? Rather than search for best practice values, it is best that you keep track of the normal functioning of your db and when you see a special summit in the values of events scattered user IO as DB file read, DB file parallel read etc and when this happens, you should check back the work you are doing and see if that can be refined somehow.

Aman...

Tags: Database

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