How to get number of Logical Reads since Database Startup?

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1

Hello all,

I use adaopr di=bp to get the number of logical reads. But now it seems that this number is truncated. ADAOPR looks like this:


$ adaopr db=11 di=bp
%ADAOPR-I-STARTED,      23-SEP-2014 18:16:53, Version 6.3.2.06 (Solaris 64Bit)

Database 11, startup at 15-JUN-2014 15:23:32
ADANUC Version 6.3.2.06, PID 6018

                       ADANUC Version 6.3.2.06
        Database 11    Buffer Pool Statistics   on 23-SEP-2014 18:16:52


Buffer Pool Size   : 1,073,741,824

Pool Allocation                        RABNs present
---------------                        -------------
Current     ( 99%) : 1,073,583,104     ASSO               :       139,226
Highwater   ( 99%) : 1,073,641,472     DATA               :        27,386
Internal    (  3%) :    38,487,040     WORK               :             0
Workpool    (  1%) :    12,425,216     NUCTMP             :           805
                                       NUCSRT             :             0

I/O Statistics                         Buffer Flushes
--------------                         --------------
Logical Reads      :**************     Total              :        12,060
Physical Reads     : 1,040,245,249     To Free Space      :             0
Pool Hit Rate      :            99.0%

                                       Write Limit  ( 27%):   289,910,070
Physical Writes    :   186,737,948     Modified     (  0%):       385,024


%ADAOPR-I-TERMINATED,   23-SEP-2014 18:16:53, elapsed time: 00:00:00
$

Is there any other way to get the logical reads?

Thanks

Matthias

2

Hi Matthias;

Would it be reasonable/feasible to reduce the time span?

3

Hello Steve,

With ADA 6.1.10, the nucleus did this automatically. Here’s the regarding line from an old nucleus-log:

Usually it was, when the logical-read-counter reaches 2^32.

Now it seems like ADA 6.3. uses a 2^64 counter - which is better than a 2^32 counter of course. But it seems senseless to me, if you can’t read it. So my question remains: Is there any other utility/option to read this counter?

Regards,

Matthias

4

I don’t think there is, so you’ll have to file an incident or raise an ER for this.

5

You can derive it from the buffer pool hit rate: The buffer pool hit rate is defined as 1 - (physical reads / logical reads).

=> logical reads = physical reads / (1 - hit rate)
=> logical reads = 1.04 billions ( 1 - 99%) = 104 billions

Regards,
Wolfgang