Re: Dash_wait_chain script resulting into ORA-01489
Date: Sun, 5 Mar 2023 11:36:56 +0530
Message-ID: <CAEjw_fh9ficP=KaYoMXpBwoi0g8J6hHCGDs_-B+yT=_xQwWAqA_at_mail.gmail.com>
On Sat, Mar 4, 2023 at 4:26 PM yudhi s <learnerdatabase99_at_gmail.com> wrote:
> Tried to capture the details from gv$active_session_history using Tanels
> "ash_wait_chains.sql" script during issue period from three different
> intervals i.e 5seconds, 10 seconds and 20 seconds and published in below
> link. This time the script didn't fail with the Ora-01489.
>
> https://gist.github.com/databasetech0073/3b8c9549ed9825a9888c8da1c74e60ac
>
> Most of those are pointing to DBWR process being the main blocker along
> with some 'log file switch checkpoint incomplete' and 'block change
> tracking' waita. So does it mean that the database writer is slow to catch
> up with the amount of DMLS which the application submits during this
> interval?
>
>
>
> On Sat, Mar 4, 2023 at 12:19 AM yudhi s <learnerdatabase99_at_gmail.com>
> wrote:
>
>> Thank You Pete. We are not seeing any signs of IO spike or Disk
>> utilization being saturated in the storage cells during this time. Below
>> are the database details.
>>
>> It's Oracle 19c. And Exadata machine.
>> Disk_asynch_io - True, filesystemio_options-None.
>> Platform- linux X86 64bit, CPU - 96, Cores- 48, Sockets-2.
>>
>> And also just to note , as I am unable to fetch the dash_wait_chain from
>> during the exact peak period as it is failing with error 'result
>> concatenation is too long' , so not sure if the above
>> supplied dash_wait_chain output from immediate before the issue period is
>> reliable to what extent.
>>
>>
>> On Fri, Mar 3, 2023 at 10:16 PM Peter Hitchman <pjhoraclel_at_gmail.com>
>> wrote:
>>
>>> Hi,
>>> I think some more detail about your set-up will help to get some answers:
>>> Oracle version
>>> Operating system
>>> Number of CPUs
>>> and
>>> The database I/O configuration (disk_asynch_io and filesystemio_options)
>>> and the set-up of the storage being used.
>>>
>>> I think that this points to the I/O subsystem not being able to keep up
>>> with the load it is being given.
>>>
>>> Regards
>>> Pete
>>>
>>
-- http://www.freelists.org/webpage/oracle-lReceived on Sun Mar 05 2023 - 07:06:56 CET