New Version Of XPLAN_ASH Utility – In-Memory Support

A new version 4.21 of the XPLAN_ASH utility is available for download. I publish this version because it will be used in the recent video tutorials explaining the Active Session History functionality of the script.

As usual the latest version can be downloaded here.

This is mainly a maintenance release that fixes some incompatibilities of the 4.2 version with less recent versions (10.2 and 11.2.0.1).

As an extra however, (more...)

Primary on FileSystem and Standby on ASM

For one of the client, standby server went down. We had another standby server which was kept down for more than a month. Decision was taken to start the server and apply incremental SCN based backup on the standby database.

The standby was on ASM and the Primary on filesystem.Incremental backup was started from the SCN reported by below query

select min(fhscn) from x$kcvfh;

Once the backup completed, it was transferred to standby, standby (more...)

“log file sync” and the MTTR Advisor

I recently investigated a performance problem on an Oracle 11.2 OLTP trading system and although we still don’t fully understand the issue (and which versions of Oracle it effects), I thought I would share what we found (and how we found it). We had a hardware failure on the database server, within 30 seconds the database had automatically been restarted on an idle identical member of the cluster and the application continued on the (more...)

Returning Error Codes from sqlplus to Shell Scripts

When I have to run SQL scripts, I prefer to do it via executable ksh scripts (I use ksh because it's usually an Oracle pre-requisite so I can rely on it being installed). One thing that I've just recently started adding into my scripts is exiting sqlplus on error and returning the ORA error code. This is done via the WHENEVER SQLERROR feature of sqlplus:

sqlplus / as sysdba <<EOF

        whenever sqlerror exit sql. (more...)

ORA-00600: [ktbdchk1: bad dscn]

Last week I had performed switchover activity of database on version 11.2.0.3 The switchover was performed using dgmgrl “swicthover to standby” command. After sometime we started receiving “ORA-00600: [ktbdchk1: bad dscn]” on the primary database.

Tue Dec 16 10:33:26 2014
Errors in file /ora_software/diag/rdbms/db02_dbv/dbv/trace/db02_ora_16271.trc  (incident=434103):
ORA-00600: internal error code, arguments: [ktbdchk1: bad dscn], [], [], [], [], [], [], [], [], [], [], []
Incident details in: /ora_software/diag/rdbms/db02_dbv/dbv/incident/incdir_434103/db02_ora_16271_i434103.trc

The trace (more...)

Upgrading to 11.2.0.4 – Dictionary View Performing Poor

Just a quick blog post on things you might see after upgrading to 11.2.0.4. We recently upgraded database from 11.2.0.3 to 11.2.0.4 and query on some data dictionary views ran too slow.

1. Performace of query on dba_free_space degraded
2. Performance of query involving dba_segments is slow

DEV01> select ceil(sum(b.bytes)/1024/1024) b from sys.dba_free_space b;

Elapsed: 01:31:45.78

Searching MOS pointed to these Doc Ids (more...)

Making Copies of Copies with Oracle RMAN

I recently had need to make a copy of an image copy in Oracle rman. Since it wasn't immediately obvious to me, I thought it was worth sharing once I had it sorted out. I was familiar with making a backup of a backup, but had never thought about making a copy of a copy.

First you need to create an image copy of your database or tablespace. For the sake of example, I'll make (more...)

ORA-16534 When Converting to/from Snapshot Standby with DataGuard Broker

We here at Seilerwerks Industries (not really) have been using snapshot standby databases to refresh an array of unit test databases from a common primary. During the business day, these would be converted to snapshot standby databases for testing, then overnight they are converted back to physical standby and recovered up to the master again.

However we ran into one problem the other week. I noticed that the test3 database was still in physical standby (more...)

Advanced Queue Quickie: Errors and Privileges

File this one under the misleading-errors department. One of my developers was working with a new queue. He pinged me when he got this error trying to create a job that used the queue:

ERROR at line 1:
ORA-27373: unknown or illegal event source queue
ORA-06512: at "SYS.DBMS_ISCHED", line 124
ORA-06512: at "SYS.DBMS_SCHEDULER", line 314
ORA-06512: at line 2

The CREATE_JOB statement was:

BEGIN
DBMS_SCHEDULER.CREATE_JOB(
job_name => 'foo.bar_q_job',
job_type => 'PLSQL_BLOCK',
(more...)

Purging SYSAUX

In continuation to my previous post “SYSAUX Growing Rapidly” , here i wanted to present the second method of purging sysaux. Basically i tried to perform the steps as mentioned in previous post and drop_snapshot_range was taking too long (> 24hrs) and still running on test db.Again WRH$_ACTIVE_SESSION_HISTORY was in top of the list occupying…

NOFILENAMECHECK Parameter Causes DUPLICATE DATABASE To Ignore DB_CREATE_FILE_DEST?

Last week I was creating a new testing database from a backup of our demo database, both under Oracle 11.2.0.3. I grabbed one of my old scripts to handle the duplicate function, which looked similar to this:

connect auxiliary /;
run {

        duplicate database to testdb
                backup location '$BACKUPDIR'
                nofilenamecheck;

}

One important difference between the demo database and this new test database is that the original demo database (more...)

Crossplatform transportable tablespaces – part 2

It took some time since I wrote a first post about TTS migration but I finished that project literally hours before my summer break. Now after couple of days while I enjoyed thermal waters and good wine of Hungary it's time to write next post.

As I described in my previous post I had to migrate database from HP-UX into Linux and also upgrade it from 10g into 12c. This time it was only PoC (more...)

die Seilerwerks 2014-08-21 13:35:00

Fresh off the heels of my earlier composite partitioning post, I just ran into this confusing issue:

SQL> alter table p_objects
  2          add partition p201410
  3                  values less than (to_date('2014/11/01','yyyy/mm/dd'))
  4          (
  5                  subpartition p201410_spdts values ('DTS')
  6                 (more...)

Adding New Partitions with Custom Subpartition Definition (Range-List)

As part of a project for work I wanted to create a script that would create a new range partition but also pre-create all the list subpartitions. By default the subpartitions would be created based on the subpartition template. However for various reasons which I won't get into we don't update or use the subpartition template. I wanted to define the subpartition list as part of the ALTER TABLE ... ADD PARTITION statement. I assumed it (more...)

11.2.0.4 DBUA silently changing NLS_TERRITORY init.ora Parameter during upgrade

In case you are planning to perform any upgrades with DBUA, double-check that the init.ora parameters after the upgrade. In a production upgrade at a client site, dbua silently changed init.ora parameter NLS_TERRITORY from GERMANY to AMERICA. It was only noticed when after the upgrade, decimal and grouping number characters were swapped, leading to application problem.

Support had to admit that it is unpublished bug 16538186 and that there is NO documentation of (more...)

ASM Startup Fails With ORA-04031 After Adding CPUs

A few weeks ago we upgraded one of our production server, adding another CPU tray. This brought the number of CPU cores from 80 to 160, and took us from 2Tb of RAM to 4Tb (just in time for Oracle to announce the in-memory database in 12.1.0.2!).

However when I went to start things up, ASM wasn't starting up, giving me these errors:

ORA-04031: unable to allocate 32 bytes of shared (more...)

De cómo un clon nos puede ayudar con un patch (updated to 12c)

Cada vez que vamos a aplicar un patch o un patch set update (PSU), el procedimiento tradicional implica detener todos los procesos que se estén ejecutando en el Oracle home directory involucrado, lo cual obliga a que dejemos de prestar servicio para iniciar el patching, proceso que si bien es relativamente fácil y sencillo, está sujeto a eventuales fallas que, de ocurrir, pueden llevar a una situación de crisis en la cual el (more...)

Don’t delete your flashback logs manually

What happen when someone will delete Oracle flashback logs ? You probably don't notice it until you will try to flashback database or bounce instance. 
There is no hope for flashback database without flashback files but there is still way to start your database again without recovery or data loss.

Here is a scenario:
[oracle@dev-6 alert]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Tue Jul 1 09:34:18 2014

Copyright (more...)

Beware April 2014 PSU and Golden Gate Integrated Capture Users

When the latest quarterly Patch Set Update (PSU) came out from Oracle, we planned to get it in place as soon as reasonable due to our need to stay current with security patches, and my need to apply what I had assumed were well-tested bug fixes for our 11.2.0.3 installations. However we were in for an unpleasant surprise.

We first applied the April 2014 PSU on our staging & development database hosts (more...)

archive_lag_target Works in SE

TL;DR: The archive_lag_target parameter will force log archiving in Standard Edition.

Just a quick note here that I wanted to share since I didn't see anything directly confirming this when I was searching around.

I have an Oracle 11gR2 Standard Edition (SE) database that I'm also maintaining a manual standby for, since Oracle Data Guard is not available in SE. I created a metric extension in EM12c to alert me if the standby is more (more...)