RMAN (and DataPump) book
Kamran Agayev's and Aman Sharma's book "Oracle Backup and Recovery: Expert Secrets For Using RMAN & DataPump" is now available on amazon. (Why do I put this on my blog ? I was one of the...
View ArticleAIOUG Sangam 13
Registration for the All India Oracle User Group conference AIOUG Sangam 13 is now open.It is in Hyderabad 08-09 November.Do register and attend if you can...
View ArticleThe DEFAULT value for a column
Here's a simple demo of how a column's DEFAULT definiton behaves.SQL> create table test_default (id_col number, data_col varchar2(5));Table created.SQL> insert into test_default values (1,NULL);1...
View ArticleGather Statistics Enhancements in 12c -- 4
In 11gR2, I have demonstrated how Gather_Stats on a Global Temporary Table defined as ON COMMIT DELETE ROWS actually does a COMMIT before gathering statistics thus actually deleting the rows before...
View ArticleAIOUG Sangam'13 Day One 08-Nov-13
I attended these sessions on Day One :Partitioning Tips and Tricks. Arup NandaStatistics Gathering. Arup NandaMultitenant Database in 12c. Arup NandaOracle HA and DR for Cloud Computing. Gaja...
View ArticleAIOUG Sangam'13 Day Two 09-Nov-13
I attended these sessions on Day Two :Managing & Troubleshooting Cluster - 360 degrees. Syed Jaffer HussainIndexes Usage in database : Tips and Tricks. Phani AregaOracle 12c Clusterware upgrade -...
View ArticleGather Statistics Enhancements in 12c -- 5
Oracle tracks the usage of columns as query predicates to determine candidate columns for the creation of histograms. In earlier versions, we would query SYS.COL_USAGE$ to identify such columns.Now,...
View ArticleGATHER_TABLE_STATS : What SQLs does it call ?. 12c
The DBMS_STATS.GATHER_TABLE_STATS procedure actually generates and executes SQL statements to collect table, column and index statistics.Let's see a simple example in 12c 12.1.0.1:SQL> create table...
View ArticleDEFAULT ON NULL on INSERT
Prior to 12c, the DEFAULT for a column would not be applied if you explicitly (or implicitly) inserted a NULL into that column. The NULL would override the DEFAULT value -- the DEFAULT would not get...
View ArticleINTERVAL Partitioning
A quick demo of INTERVAL Partitioning.(This demo in 11.2.0.2)SQL> create table hkc_test_intvl_date 2 (date_column date, 3 data_column varchar2(50)) 4 partition by range (date_column) 5 interval...
View ArticleLAST_CALL_ET in V$SESSION
The LAST_CALL_ET column in V$SESSION represents, for an ACTIVE, session "represents the elapsed time (in seconds) since the session has become active."So, if you are running an DML operation, it...
View ArticleMy first Backup and Recovery Quiz
I have created a short 5 question quiz on Oracle Backup and Recovery at QuizBean. Please test it. You can submit your comments against this blog post. (I want to see if QuizBean is reliable)....
View ArticleThe difference between SELECT ANY DICTIONARY and SELECT_CATALOG_ROLE
I've seen some DBAs confused about these two "privileges" or "roles".SELECT ANY DICTIONARY is a System Privilege.SELECT_CATALOG_ROLE is a Role you would see in DBA_ROLES. However, querying...
View ArticleDatabase Technology Index
A very useful page / link.Oracle Database Technology Index (not strictly 12c only)...
View Articlelogin.sql does not require a login
Oracle's sqlplus can use a login.sql file to execute commands -- e.g. setup options.This file is read and executed when you start sqlplus, even without having logged in to a database.Here's a quick...
View ArticleAn SQL Performance Quiz
Markus Winand has written a very small SQL Performance Quiz. (I scored 5 out of 5 on Oracle).He has published a review of the results. A very large number of visitors have failed. ...
View ArticleSQL Analytics
Oracle Learning Library video series on SQL Analyticshttp://apex.oracle.com/pls/apex/f?p=44785:24:0:::24:P24_CONTENT_ID,P24_PREV_PAGE:8814,1...
View ArticleRMAN Image Copy File Names
RMAN provides a convenient way to name Image Copies (backups) of datafiles to retain the same file name without the path.Here's a demo :[oracle@localhost ~]$ cd /IMA*/ORCL*[oracle@localhost ORCL_DB]$...
View Article"Dropping" an Index Partition
Here is a simple way to "drop" an Index Partition using the 11.2 behaviour of DEFERRED_SEGMENT_CREATION by dropping the segment for the Index Partition.CORRECTION : Although I posted this as...
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