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Mar 29 2020
Franck Pachot

Oracle recovery concepts

By | Oracle | No Comments

I’ve published a while ago a twitter thead on some Oracle recovery concepts. For those who are not following twitter, I’m putting the whole thread here:   🔴⏬ Here I start a thread about some Oracle Database concepts. We will see how far it goes - all questions/comments welcome. 🔴⏬ A database (or DBMS - database management system) stores (for short and long term) and manipulates (from many concurrent users/devices) your #data. 🔴⏬ #data is logically structured (tablespaces, schemas, tables, columns, datatypes,…

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Mar 28 2020
Clemens Bleile

A change in full table scan costs in 19c?

By | Database Administration & Monitoring, Oracle | No Comments

During tests in Oracle 19c I recently experienced this: [email protected]@orcl> select * from demo4 where m=103; [email protected]@orcl> select * from table(dbms_xplan.display_cursor); … ————————————————————————— | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ————————————————————————— | 0 | SELECT STATEMENT | | | | 26439 (100)| | |* 1 | TABLE ACCESS FULL| DEMO4 | 1 | 10 | 26439 (14)| 00:00:02 | ————————————————————————— –> The costs of the full table…

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Mar 27 2020
Franck Pachot

Oracle disables your multitenant option when you run on EC2

By | Cloud, Oracle | 3 Comments

I have installed Oracle 19.6 on an EC2 for our Multitenant Workshop training. And of course, during the workshop we create a lot of PDBs. If you don’t have paid for the Enterprise Edition plus the Multitenant Option you can create at most 3 pluggable database. But with this option you can create up to 252 pluggable databases. Does it worth the price, which according to the public price list is USD 47,500 + 17,500…

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Mar 22 2020
Morgan Patou

Documentum – LSS registerOracleVersionView script with wrong content

By | Application integration & Middleware, Entreprise content management | No Comments

As discussed in a previous blog, working with LSS might prove a little bit challenging from time to time. In this blog, I wanted to share an error I saw while installing LSS 16.6.1 on an Oracle database. Initially, I developed my silent installation for LSS (while encapsulate the LSS silent scripts provided by OpenText) using a PostgreSQL database because it’s usually easier to setup an environment on Kubernetes with PG because of licenses.  …

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Feb 24 2020
Franck Pachot

Oracle 20c SQL Macros: a scalar example to join agility and performance

By | Cloud, DevOps, Oracle | One Comment

By Franck Pachot . Let’s say you have a PEOPLE table with FIRST_NAME and LAST_NAME and you want, in many places of your application, to display the full name. Usually my name will be displayed as ‘Franck Pachot’ and I can simply add a virtual column to my table, or view, as: initcap(FIRST_NAME)||’ ‘||initcap(LAST_NAME). Those are simple SQL functions. No need for procedural code there, right? But, one day, the business will come with new…

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Feb 09 2020
Franck Pachot

Running SQL Server on the Oracle Free tier

By | Cloud, Oracle, SQL Server | 2 Comments

By Franck Pachot The Oracle Cloud is not only for Oracle Database. You can create a VM running Oracle Linux with full root access to it, even in the free tier: a free VM that will be always up, never expires, with full ssh connectivity to a sudoer user, where you are able to tunnel any port. Of course, there are some limits that I’ve detailed in a previous post. But that is sufficient to…

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Feb 04 2020
Franck Pachot

ROLLBACK TO SAVEPOINT;

By | Oracle | 2 Comments

By Franck Pachot . I love databases and, rather than trying to compare and rank them, I like to understand their difference. Sometimes, you make a mistake and encounter an error. Let’s take the following example: create table DEMO (n int); begin transaction; insert into DEMO values (0); select n “after insert” from DEMO; update DEMO set n=1/n; select n “after error” from DEMO; commit; select n “after commit” from DEMO; The “begin transaction” is…

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Jan 22 2020
Jérôme Dubar

Make Oracle database simple again!

By | Database Administration & Monitoring, Database management, Development & Performance, Hardware & Storage, Operation systems, Oracle | 6 Comments

Introduction Let’s have a look at how to make Oracle database as simple as it was before. Oracle database is a great piece of software, yes it’s quite expensive, but it’s still the reference and most of the companies can find a configuration that fits their needs according to a budget. Another complain about Oracle is the complexity: nothing is really simple, and you’ll need skillful DBA(s) to deploy, manage, upgrade, troubleshoot your databases. But…

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Jan 08 2020
Clemens Bleile

ARRAYSIZE or ROWPREFETCH in sqlplus?

By | Database Administration & Monitoring, Oracle | No Comments

ARRAYSIZE or ROWPREFETCH in sqlplus? What is the difference between the well known sqlplus-setting arraysize and the new sqlplus-12.2.-feature rowprefetch? In Blog https://blog.dbi-services.com/oracle-fasttrue-in-sqlplus-some-thoughts-about-rowprefetch/ I showed a case, which helps to reduce the logical IOs when using rowprefetch. Here the definition of arraysize and rowprefetch according the documentation: arraysize: SET System Variable Summary: Sets the number of rows, called a batch, that SQL*Plus will fetch from the database at one time. Valid values are 1 to…

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