Category: Databases

Nov 22

Background Processes

I swear that as I get further and further along in my Oracle career, I have a harder and harder time keeping up with Oracle’s background processes. I’d like to chalk this up to getting older, but after digging into it, I’m pretty sure its just Oracle’s explosion of background processes in 11g that is …

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Nov 11

Installing RAC for a Database with Datafiles

Not that long ago, I needed to upgrade Oracle Clusterware and RDBMS from 11.1.0.7 to 11.2.0.2. I have tons of experience with the Oracle RDBMS software, but I suspect that I am like most DBA’s in that my Clusterware experience is not at the same level as my RDBMS experience. So while I had no …

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Oct 12

11gR2 Compression Advisor = Evil

I recently upgraded to 11.2.0.2 from 11.1.0.7. Immediately after the upgrade, I noticed a spike in our redo generation. I also noticed tables with names like DBMS_TABCOMP_TEMP_UNCMP and DBMS_TABCOMP_TEMP_CMP. What are those tables doing in my production schemas and how did they get there? After digging, I was able to find out that these are …

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Oct 06

LOB RETENTION

In the past, one would use the PCTVERSION storage parameter for their LOB segments to reserve a percentage of storage space for read consistency of LOB segments. In Oracle 11g, you can now use the RETENTION parameter. The RETENTION parameter will use the UNDO_RETENTION parameter for determining how long to keep LOB data for read-consistency …

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Oct 05

Upgrading Grid Control After Manual DB Upgrade

I recently went through multiple database upgrades. Some of the databases were upgraded using the DBUA utility. The DBUA utility does a nice job of modifying the database’s information in Grid Control to match the new database version. When doing the database upgrades, I also had to perform some manual upgrades. When you manually upgrade …

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Sep 06

Clone ORACLE_HOME

I have begun a major upgrade of our primary production Oracle database from 11.1.0.7 to 11.2.0.2. We have 5 test environments and 12 development environments. This is small compared to many shops, but is big enough to make installing Oracle 11.2.0.2 on each and every environment a big of a pain. I tried to use …

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Aug 01

Dumping Data Blocks

I was recently working on some data block corruptions and I needed to dump some data blocks to verify its contents. I had to brush off a paper I wrote a long time ago which showed how to do this. What follows is a portion of that paper: To dump a block belonging to a …

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Jul 19

ORA-4031 errors with Direct NFS

This is an old problem for me which I resolved quite a while ago, but I figured I’d finally write it up. When I started at my new company, the production database would crash about once a month with ORA-4031 memory errors. The current DBA figured the problem was lack of bind variables in application …

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Jul 18

ORA-12519 TNS: no appropriate service handler found

Every 10 minutes or so, I have Grid Control sending me an alert similar to the following: Failed to connect to database instance: ORA-12519: TNS:no appropriate service handler found (DBD ERROR: OCIServerAttach). The database was running just fine and should be up and running. Signing on to the database server and issuing “lsnrctl status” showed …

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Jul 18

DBCA Create Database bad REMOTE_LISTENER

I recently upgraded Oracle Cluster Ready Services 11.1.0.7 to Oracle Grid Infrastructure 11.2.0.2 on a testbed. I then attempted to run the DBCA to create an Oracle 11.1.0.7 on top of the 11.2.0.2 Grid installation. After walking through the DBCA wizard,I would always receive messages similar to the following: ORA-00119: Invalid specification for system parameter …

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