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Database Feed

Oracle Database, Oracle 10g, Oracle 11g, Oracle XE, Oracle RAC, Oracle Instant Client, Oracle Data Guard and Oracle Exadata resources, news, and support articles.

Advert: SAGE Computing Services Training - 2011

This April SAGE Computing Services are holding a training event that may interest beginners, business users, testers & developers alike.

Automatic log gathering for Grid Control 11.1

Still debugging the OMS problem (it occasionally hangs and has to be restarted) I wrote a small shell script to help me gather all required logs for Oracle support. These are the logs I need for the SR, Niall Litchfield has written a recent blog post about other useful log locations.

Stress Testing Oracle XE 10g

Oracle Express Edition (XE) is Oracle's free entry-level database product, currently available only in a 10g version. XE is usually pitched as suitable for personal work or (very) small departmental applications, but I was curious as to what kind of load it can support.

Oracle XE 10g has the following limitations:

run utlrp.sql script and ORA-07445: [kttuser0()+293]

After imported METADATA from 10.2 to 11.2... I found "INVALID" status on objects, then used "utlrp.sql" script:

SQL> @?/rdbms/admin/utlrp.sql
< lost connection >

In alert log file:
Tue Mar 01 14:19:49 2011
SERVER COMPONENT id=UTLRP_BGN: timestamp=2011-03-01 14:19:49

Keep the faith

A frequent query request is that, when you've used MAX or MIN to find the highest, latest or otherwise most favoured row(s), you want the values of the other columns in that row.

Often a suggested answer is the use of a sub-query. But this overlooks one of those less well known features in Oracle SQL, the KEEP clause.

Consider the test case:

create table test_max 

Oracle Database Time Model Viewer in Excel 2

March 1, 2011 (Updated March 2, 2011) (Back to the Previous Post in the Series) (Forward to the Next Post in the Series) In the previous blog article in this series, we examined the output generated by one of my programs.  Most of that output was centered on the analysis of the time model statistics in Oracle Database [...]

Listener Commands

Syntax : set current_listener 
LSNRCTL> set current_listener LISTENER
LSNRCTL> show current_listener
Syntax : set displaymode 
LSNRCTL> show displaymode
Service display mode is NORMAL
LSNRCTL> set displaymode VERBOSE
Syntax : set inbound_connect_timeout 
LSNRCTL> set inound_connect_timeout 0
Syntax : set log_directory 
LSNRCTL> set log_directory 

For the Love of AWR and ASH…

Yes, I love AWR and ASH reports when performing database detective work.  They are an essential tool in my performance tuning arsenal, along with the logs, trace files/profiling, Oracle Enterprise Manager and a suite of personally collect queries from over the years.  As complex as databases are these days, the more data that I have at hand to backup what I am tuning or reporting on, the more comfortable I am, (OK, so I’m not one for “theories”… :) )

How can I confirm there was an I/O problem (2) ?

In a previous post, I have mentioned that I have tried to mine AWR data to confirm an I/O issue occurred around 2:18 PM of Feb 18; however I encountered some issue and instead found out 'sar' was helpful. Today, I worked out the query against AWR tables. The query is as follows:

rem  awr_io_file_smpl.sql  
rem -- Adapted from the scripts written by Karl Arao:

Where is METHOD_OPT SIZE REPEAT’s repeat value stored?

In my last post When does METHOD_OPT SIZE REPEAT not obey we saw how SIZE REPEAT sometimes appears to know best and creates a FREQUENCY histogram with a different number of buckets than previously specified.

The mechanics of this became clearer while pondering another question that I often ask myself.

How does METHOD_OPT SIZE REPEAT remember the value last specified in order to repeat it?

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