Comments for Tanel Poder's Performance & Troubleshooting blog

[...] A documented method consists in using adrci (ADR command interpreter) but I wanted an easier method, so I searched on the net and found this thread in Tanel Poder’s Blog (http://blog.tanelpoder.com/2009/03/21/oracle-11g-reading-alert-log-via-sql/). [...]

Nice, prEVILedge :)

Thanks for the post .
I have a question about sharing tablespaces using transportable TS :-
I share same read-only tablespace (same data files) between two different databases . When I drop a table from one database I can see the temporary segments like you said , but the same object in the other database has no impact even though it shares the same datafiles and tablespace . how?

Hi,
Very nice and informative presentation.
Well i have not worked on Oracle Exadata, but gathering what all is available on net and trying to compare with the NoSQL data bases like Cassandra, HBASE, Couchve, Mongo etc..It would be great if you can throw some light on the following questions:

1. What is the write latency? For example:if i have billion records per second coming to me, then how much does time it takes to load into OLTP?
2. What would be the read latency if simulatenous writes are also happening?:
Consider the worst case scenario and full peak load

Thanks and Regards,
Som Shekhar

[...] Node Cluster Filed under: Basics, Performance, RAC — coskan @ 11:34 am Since I got turbo boost (over 1000 hits a day-wooow) from Tanel Poder the Great, better I write something to deserve the [...]

When we set a value for PGA_AGGREGATE_TARGET parameter, oracle can use more OS memory for PGA than what we set in PGA_AGGREGATE_TARGET when it is required, with 11g AMM does this work same way? Can oracle allocate more than MEMORY_MAX_TARGET for PGA when it is required?

Thanks

Tanel,

” but basically what it shows is that the SQL_EXEC_ID consists of the query coordinator’s instance_id value and the execution number for a SQL_ID in the instance where the query coordinator session was logged in:”

I think it uses the instance if of teh QC to keep track of where the PX query origniated from.
While the Instance id of the query coordinator is used to keep track of where the QC session resides, I would think it is using the execution count based on the instance on which the PX slave(s) is running and not the execution number from the instance where the QC is running. If that was the case, the max(xxx) value you posted will all be the same. Is it not?

Tanel,

I get the following error message when I run it on Solaris. Any idea? It works fine on Linux or AIX.

SQL> @snapper ash 5 1 ALL
Sampling SID ALL with interval 5 seconds, taking 1 snapshots…

– Session Snapper v3.13 by Tanel Poder @ E2SN ( http://tech.e2sn.com )

———————————————————————–
Active% | SQL_ID | EVENT | WAIT_CLASS
———————————————————————–
declare
*
ERROR at line 1:
ORA-00979: not a GROUP BY expression
ORA-06512: at line 831
ORA-06512: at line 1364

Thanks,
Venu

Tanel,

Do we have any dates for online trg (Advanced Oracle Troubleshooting v2.0 Part 1 & part 2) after 2nd dec. I am planning to take both , but need to get budget approved from my company for that. It would be great if we can have some dates for the same

[...] ORA-04031 errors and monitoring shared pool subpool memory utilization with sgastatx.sql [...]

[...] The tool can be especially helpful in 11g because x$kcbsw (x$kcbuwhy in 11g) is not populated properly there. Note: Examples of using view x$kcbsw: – Investigating Logical I/O by Jonathan Lewis – Finding the reasons for excessive logical IOs by Tanel Poder [...]

I have seen your awareness about this theme when you post it and it really gives an informational message to us readers. I am hoping that you will continue writing this kind of blog. Thanks for sharing this information. http://www.mesotheliomanewsnow.com

Tanel,
are You planning to share presentation slides ?
Regards
GregG

Does someone know a way to duplicate a database and keeping the original rowid ?

Good post.With very nice explanation…

Best regards,

Rafi.

Hi Tanel
we have plsql code calling java which is stored in database.
i see the plsql code many times waiting on latches such as library cache pin or ‘latch: row cache objects’
I tried LatchProf but did not get information related to query or database object in contention
Also is there any way to find what java code or java stored procedure session is executing.
When i see ADDM reports or awr reports always java executions shows in top
but can drill down to exact java stored procedure in question

Any help regarding this is appreciated

regards
KG

I had no luck on 11.2.0.3 on Linux:
1 begin
2 dbms_resource_manager.switch_consumer_group_for_sess(
3 27,25,’CANCEL_SQL’);
4* end;
SQL> /
begin
*
ERROR at line 1:
ORA-29366: invalid CONSUMER_GROUP argument specified
ORA-06512: at “SYS.DBMS_RMIN”, line 505
ORA-06512: at “SYS.DBMS_RESOURCE_MANAGER”, line 916
ORA-06512: at line 2

Very interesting. I wonder what it’s used for and why it was exposed to v$ views. I’ve troubleshot lots of problems involving spinning processes, unexpected loops, bad sql plans, etc. In those scenarios, usually more than one statement is involved. If I understand correctly, I would think that counter would turnover constantly. I’m curious and puzzled by it. Clearly, there is/was a reason for it’s creation.
—
I’m behind on my reading. I hope I’m not past the relevance date :)

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