Recently I had to battle a new issue with the quite-new Oracle Database RAC Version 12.2.0.1 on Linux x86_64. The idea of RAC is, to compensate the loss of a node or service by restarting services on other nodes. But in my case, when one node in a two-node-Cluster was down (or the crs stack […]
Restarting Oracle for Performance is like a Coitus for Virginity
Today I had another case of that … total breakdown of a live environment by infrastructure defect, bad enough. Customer rushing up the database and all apps services, just to see thousands of locks and hanging transactions. Big panic, frequent restarting of databases and applications. Getting worse, finally calling me. Told them I’ll manage that, asked […]
Oracle RMAN destination with variable restrains “not backed up” clause
Today I was a bit surprised – being always under the impression that Oracle RMAN should accept “backup backupset not backed up to destination ‘xyz’” AND work with it successfully. But I learned that in 11.2.0.4 the Oracle RMAN “to destination” containing variables restrains the “not backed up” clause. No error thrown, but just does not work […]
Oracle Database 12.2 on-premises release dates
Oracle recently announced the availability of Oracle Database 12c release 2 (12.2) for on-premises servers. https://www.performing-databases.com/en/2017/01/oracle-database-12-2-on-premises-release-dates/ Linux x86-64, Solaris SPARC and Solaris x86-64: 15-Mar-2017 Other supported platforms (Windows x86-64, IBM AIX on POWER, IBM Linux on System z, HP UX Itanium): Q2CY2017 Source: MOS DOc ID 742060.1 […]
Oracle Enterprise Linux 7: How to stop bash tab completion from escaping the dollar $
Did you ever wonder why bash in Oracle Linux, Red Hat Enterprise Linux and other recent Linuxes escapes the dollar sign ($) when completing paths with the tabulator (tab) key like that: [oracle@oratest01 ~]$ (KLM12102) ls -l \$ORACLE_BASE/diag Answer In bash >= 4.2.29 you have a “direxpand” option, which is NOT set by default. The […]
Oracle: How to identify SQL doing TABLE ACCESS FULL on a given partition
In my last post, I described a quick show case for Oracle 12c Automatic Big Table Caching. But ABTC is just a crock, nevertheless a useful one. The biggest help from Automatic Big Table Caching for “sustainable” database performance management is the temperature of segments, heated up by TABLE ACCESS FULL. In my case, after enabling ABTC […]
Oracle Automatic Big Table Caching – an improvement, not a fix
Too much TABLE ACCESS FULL in your Oracle Database? Thus, SQL elapsed time too slow for the demand? Plenty of Buffer Cache to create a temporary fix? maybe you want to consider Automatic Big Table Caching. Usually, Oracle only does Full Table Caching for small tables. Big ones will only use the Buffer Cache for the current chunk […]
Oracle 11g unable to extend datafile but ASM disk group shows free space
Sometimes Oracle Database 11gR2 complains about not being able to extend a (lob) segment with ORA-1691, but ASM monitoring based on USABLE_FILE_MB did not fire. Adding a new data file fails with ASM ORA-15041. I was under the impression this behaviour of ASM deserved some explanation. Situation Database Alert Log complains with ORA-1691: ORA-1691: unable to extend lobsegment MYUSER.SYS_LOB0013128030C00003$$ […]
My COLLABORATE16 look-at’s – an aftermath
From April 10th to April 14th 2016 many Oracle professionals congregated in Las Vegas. The three big U.S. user groups, the IOUG, the OAUG and the Quest User Group once again formed one of the best Oracle Conferences in the world: COLLABORATE16. I was honored to be there as a speaker, and glad to perform […]
Oracle SQL showing current expensive queries plus most expensive object from execution plan
Sometimes, it’s useful to see what’s currently going on in your Oracle Database. This query is meant to help with this task, that haunts every DBA from time to time. It’s just using v$sql and v$sql_plan, so no need for Enterprise Edition and Diagnostics Pack. Key features: find top buffer getters per execution from v$sql […]