oracle queries needed


I want SQL queries for these two scenarios

Q. 1) Anagrams of a string i.e. let a name is RAMESH. So all combinations of letters of word RAMESH.
Probably a procedure needs to be written for this eg RAMESH, RHSEMA. There will be 6*5*4*3*2*1 combinations

Q.2 ) There is one table PERSON as follows:

Decision Tree Algorithm in Spark SQL


Decision Tree Algorithm in Spark SQL
Written JP Vijaykumar
Date Sep 14 2020

This script is provided for educational purpose only.
Pls modify/change the script as may be required to suit your environment.

I presented a script to process decision tree algorithm using pl/sql earlier.
I like spark sql for the following reasons:
01) It is open source.
02) It combines the rich functionality of python and sql
03) It has the datamining libraries.
04) can be installed on my desktop and play around.

database block size - does it really matter?


What block size should you use? For what purpose? How about tablespaces in different block sizes? Any opinions?

Installing database 19c on Oracle Linux 8


Database release 19.7 (ie, 19c with the April 2020 RU) is at last certified for OL8, but there may be some hacking needed to get it installed.

This certification is long overdue: our security admin has been pushing for the 5.x kernel for some time, and OL7 still only supports kernel 4.x. I'm starting to move some production systems over now using the July RUR, which takes the release to 19.7.1.

Begin by installing the Oracle Validated rpm from the ol8_UEKR6 repository:

yum install oracle-database-preinstall-19c

Controlling distributed queries with hints


Recently I've been working on tuning some distributed queries. This is not always straightforward.

Devart Presents Dramatically Improved dbForge Studio for MySQL v.9.0


Devart introduced the new version of its key tool, dbForge Studio for MySQL, v.9.0. Almost every feature of the IDE was examined and significantly improved.

Devart, a recognized vendor of professional database management software for developers and DBAs, released dbForge Studio for MySQL, v9.0. The updated version delivers completely new functionality, including Find Invalid MySQL Objects, provides new connectivity options, and contains massive improvements of existing features, including MySQL Data and Schema Compare, Data Import and Export, Code Completion, and much more.



Written JP Vijaykumar
Date Mar 8th 2020

Database 20c docs


Now available!

Going through the New Features guide, there is a shed load of wonderful enhancements. Then you look at the Licensing guide, and most of them require Exadata or Oracle Cloud or both.

Recover a database using RMAN but failing to open redo


When using RMAN to restore and recover the database, it seems to work OK - no obvious errors during the restore / recovery, as far as I can see. The issue seems to be when I try to 'alter database open resetlogs'... after this the database shuts down. At this point, I don't really care about losing some of our data, this is just a test system, my main concern is how to get the database working again.

Oracle version 12.1.0.

1. I startup with nomount.

RMAN> startup nomount;



Written JP Vijaykumar
Date Jan 4th 2020
Modified Jan 5th 2020
This article/script is provided for educational purpose ONLY.
The readers are advised to make necessary changes to the script as may be required for their use in their respective environments.
Pls test these scripts thoroughly in a lower environment, ONLY if you are satisfied with the tests' results, then ONLY use in any


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