Category: 12c New Features

Mar 01

Christmas Comes Early (Oracle 12.2)

Christmas must be coming early! We were previously informed that Oracle 12.2 would be released on March 15, 2017, but you can get it today for Linux and Solaris platforms. Simply go to http://otn.oracle.com and download the new version today. No longer is 12.2 “cloud only”.   Sadly, My Oracle Support is not up-to-date with …

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Feb 18

Oracle 12c IDENTIFIED BY VALUES

Since I can recall in my career working with Oracle, I’ve been able to modify a user’s password to the password hash. The trick I’ve sometimes employed was to store the userid/password hash, change the password to something I know, connect to the database as that user and then do my work. When done with …

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Dec 22

A Trip Through the GIMR

Oracle Grid Infrastructure includes the Cluster Health Monitor (CHM) which regularly captures OS-related performance information. In early versions, CHM use a Berkeley DB for its data store. In Grid Infrastructure 12.1.0.2, it is now required to use an Oracle database for the data store. This Oracle database is called the Grid Infrastructure Management Repository (GIMR). …

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Dec 02

SQLT in 12c Can’t Gather Stats

After upgrading to 12c, I did have some issues where processing in our database was running into the following errors: ORA-20000: Unable to gather statistics concurrently: insufficient privileges The fix was pretty easy. I found information on Tim’s Oracle Base website on the workaround here: https://oracle-base.com/articles/12c/concurrent-statistics-collection-12cr1 Today I tried to run SQLT’s sqlxtract script to help …

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Nov 05

Adaptive Dynamic Stats Kills Performance in 12.1.0.2 RAC

After a recent upgrade to 12.1.0.2, I’ve been working on a number of performance issues. Many such issues are related to poor SQL and a number of issues I’ve resolved I’ve proven were issues in the old 11.2.0.4 release. This just means it’s always been an issue. But people are taking the opportunity of the …

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Oct 28

Cursor Obsoletion Dump

After our recent upgrades to Oracle 12.1.0.2, we noticed a few non-production databases that were filling up the DIAGNOSTIC_DEST. There were huge trace files in there which contained this type of information: —– Cursor Obsoletion Dump sql_id=6aca4drrt76x3 —– Parent cursor obsoleted 1 time(s). It appears this is a known bug in 12.1.0.2. Oracle turned on …

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Oct 26

12.2 RAC/GI New Features

I attended a session today at Oracle Open World 2015 by Markus Michalewicz which highlighted some new features we can look forward to for Oracle Grid Infrastructure 12.2, currently in beta.  There were lots of new features, but a few stood out as major changes to the architecture. Oracle 12.1 introduced Flex Clusters about two …

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Oct 26

Oracle 12cR2 now in Beta

Today at Oracle Open World 2015, I learned that Oracle12cR2 is now in beta. I attended a session from Oracle VP Andy Mendelsohn where he highlighted a few of the new features found in 12.2. This is not an exhaustive list, but contains some highlights from that session.   Sharding for web-scale applications Table and …

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Oct 21

Oracle 12c Upgrade Issues

I recently upgraded a critical production system from Oracle 11.2.0.4 to 12.1.0.2. This is also a 3-node Oracle RAC database. I ran into a few issues which needed resolution after the upgrade. Hopefully this helps out others in their upgrades. The first issue was related to a Global Temp Table that is central to our …

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Oct 02

12c Adaptive Plans in SQL Developer

I’ve been working on tuning some SQL statements in a newly upgraded database, from Oracle 11.2.0.4 to 12.1.0.2. As I typically do, I like to use SQL Developer to see the Explain Plan. I was surprised to see some gray text in the Explain Plan output, which you can see below.         …

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