RE: A VLDB contest
- From: "Luca Canali" <Luca.Canali@xxxxxxx>
- To: "ORACLE-L" <oracle-l@xxxxxxxxxxxxx>
- Date: Wed, 30 Aug 2006 09:29:26 +0200
Hi Kevin,
From my largest DB:
POOL NAME BYTES
------------ -------------------------- ----------
shared pool ASM extent pointer array 185352360
I imagine this memory is strictly related to X$KFFXP, correct me if I am
wrong.
Thanks,
L.
PS:
From the same DB:
SQL> select sum(TOTAL_MB) from v$asm_diskgroup_stat;
SUM(TOTAL_MB)
-------------
24398576
Does this mean that Oracle is using on average 9 bytes per extent ?
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Kevin Closson
Sent: Wednesday, August 30, 2006 1:39 AM
To: Bobak, Mark; ORACLE-L
Subject: RE: A VLDB contest
Right, the ASM instance gives the pointer array info to the
consumer instances where it is cached in the shared pool.
I've not seen one iota of discussion on this list about how
Oracle maps a data block to an extent within an ASM diskgroup.
Must not be an interesting topic?
It is indeed using these pointers. Such mapping is never free. Volume
managers have always had to do that--but have always stored
such mappings in kernel memory. No FUD intended here. I just
wanted to get people curious about the topic.
________________________________
From: Bobak, Mark [mailto:Mark.Bobak@xxxxxxxxxxxxxxx]
Sent: Tuesday, August 29, 2006 4:30 PM
To: kevinc@xxxxxxxxxxxxx; ORACLE-L
Subject: RE: A VLDB contest
I don't have an 'ASM extent pointer array' at all in my ASM
instance....
1 select * from v$sgastat
2 where name like '%ASM%'
3* order by bytes
SQL> /
POOL NAME BYTES
------------ -------------------------- ----------
shared pool ASM rollback operations 2592
shared pool ASM map operations 3360
shared pool ASM db client 11840
shared pool ASM buffer object 37288
shared pool ASM file 75328
In my database instance that relies on ASM, however.....
1 select * from v$sgastat
2 where name like '%ASM%'
3* order by bytes
SQL> /
POOL NAME BYTES
------------ -------------------------- ----------
shared pool ASM rollback operations 2592
shared pool ASM map operations 16856
shared pool ASM file 19200
large pool ASM map operations hashta 393216
shared pool ASM extent pointer array 9527624
-Mark
--
Mark J. Bobak
Senior Oracle Architect
ProQuest Information & Learning
Ours is the age that is proud of machines that can think and
suspicious of men who try to. --H. Mumford Jones, 1892-1980
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Kevin Closson
Sent: Tuesday, August 29, 2006 7:24 PM
To: ORACLE-L
Subject: A VLDB contest
Does anyone actually have ASM "put to the test" as they say?
Anyone
have huge ASM extent pointer array areas within their shared
pool? Anyone
have "ORA-4031-creeping syndrome" ?
For instance:
select * from v$sgastat;
POOL NAME BYTES
------------ -------------------------- ----------
shared pool ASM extent pointer array 287097144
Anyone see 1GB or more?
Kevin Closson
Chief Architect, Oracle Database Solutions
PolyServe, Inc
kevinc@xxxxxxxxxxxxx
http://www.polyserve.com/oracle_consolidation.php
<http://www.polyserve.com/oracle_consolidation.php>
http://www.polyserve.com/oracle_rac_clusters.php
<http://www.polyserve.com/oracle_rac_clusters.php>
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