Re: RMAN question(s)

On 9/17/07, Allen, Brandon <Brandon.Allen_at_oneneck.com> wrote:

>
> In case anyone is interested - I did a test of the 10g "as compresssed"
> backupset on a 285GB databases and here are the results:
>
> ...
> So, I can't really make any conclusions on the backup time yet due to
> the large variance in backup times on this environment, but it's clear
> that the space savings was significant (280-36=244 & 244/280=87%
> reduction) and the runtime from this one sample was close to the bottom
> of the normal range so that's promising.
>

The data in v$backup_sync_io and v$backup_async_io may provide better information after the fact. I too find it difficult to get a system suitable for testing.

The data in these views is not persistent, so you need to get it after the backup
completes and save it.

I've pasted a script at the end of this post to get you started with it, if you
would like to use it.

-- 
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist


--------------------------------------------------

-- rman_io_stats.sql
-- aggregation of compatible stats
-- from the v$backup_async_io and v$backup_sync_io views
--

alter session set nls_date_format = 'mm/dd/yy hh24:mi:ss';

col device_type format a10 head 'DEVICE|TYPE'
col type format a15
col filename format a40 head 'FILENAME' TRUNC
col buffer_size format 99,999,999,999 head 'BUFFER SIZE'
col buffer_count format 9999 head 'BFFR|CNT'
col open_time format a18 head 'OPEN TIME'
col close_time format a18 head 'CLOSE TIME'
col elapsed_time format 999,999 head 'ELAPSED|SECONDS'
col set_stamp format 9999999999 head 'SET STAMP'
col set_count format 99999 head 'SET |COUNT'

col megabytes format 99,999,999.0 head 'MEGABYTES'
col total_megabytes format 99,999,999.0 head 'TOTAL|MEGABYTES'
col effective_bytes_per_second format 999,999,999 head 'EFF BYTES|PER
SECOND'
col io_count format 999,999,999 head 'IO COUNT'


set line 200

break on set_stamp skip 1 on set_count

--spool rio.txt

SELECT
        set_stamp


        , set_count

        , open_time

        --, close_time


        , device_type

        , type

        , filename

        , buffer_size

        , buffer_count

        , bytes / 10485760 megabytes

        , total_bytes / 10485760 total_megabytes

        , effective_bytes_per_second

        , io_count

        , elapsed_time/100 elapsed_time -- stored in centiseconds

FROM v$backup_async_io -- disk
union
SELECT
        set_stamp


        , set_count

        , open_time

        --, close_time


        , device_type

        , type

        , filename

        , buffer_size

        , buffer_count

        , bytes / 10485760 megabytes

        , total_bytes / 10485760 total_megabytes

        , effective_bytes_per_second

        , io_count

        , elapsed_time/100 elapsed_time -- stored in centiseconds

FROM v$backup_sync_io -- tape, probably. could be disk
ORDER BY 1,2,3
/

--spool off
--ed rio.txt

--
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