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All posts by Mouhamadou Diaw

Mouhamadou Diaw
Consultant

Mouhamadou Diaw has more than ten years of experience in IT domains. He is specialized in Oracle technologies (engineered system, architecture, backup and recovery, high availability, security, audit etc.). Mouhamadou Diaw is Oracle professional Certified (8i, 10g, 11g, 12c), Oracle RAC 11gR2 Certified Expert , Oracle Database 11g Security Certified and CISA (Isaca). He received a Doctorate in Heat and Humidity Transfer of INSA Toulouse, France. His branch-related experience covers Insurance, Retail, International Organizations, Transport & Logistics, etc.
Mouhamadou Diaw

PostgreSQL 10 Beta 1: Logical replication

By | Database Administration & Monitoring | No Comments

In a previous blog we talked about partition in postgreSQL 10 Beta 1. In this article we will talk about another new feature logical replication. Yes in postgreSQL 10, logical replication is now impelemented. We can replicate one table or many tables. In our example we are replicating between two clusters in the same server. The primary cluster is running on port 5432 and the second on port 5433. But of course we an use…

 
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Mouhamadou Diaw

History of Upgrading 9 Tb PostgreSQL database

By | Database Administration & Monitoring | No Comments

In this blog I am going share a history of PostgreSQL migration and upgrade from 9.2 to 9.6. Let me first explain the context We have a PostgreSQL environment with following characteristics. Note that real database name, server name are changed for security reason Host: CentOS release 6.4 PostgreSQL version: 9.2 Database size : 9Tb postgres=# select version(); version ————————————————————————————————— ———— PostgreSQL 9.2.4 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2- 52),…

 
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Mouhamadou Diaw

PostgreSQL 10 Beta 1: Native Table Partitioning

By | Database Administration & Monitoring | No Comments

The Beta 1 version PostgreSQL 10 is now released with lot of new features. One of the most popular is the native support of table partitioning. In this blog we are going to see how we can implement partitioned table in PostgreSQL 10. Note that RANGE and LIST partition are the supported methods. In following example RANGE partition is used. The first step is to create the table to be partitioned, let’s say for example…

 
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Mouhamadou Diaw

Upgrade to Oracle 12.2 with dbupgrade utility

By | Database Administration & Monitoring | No Comments

Oracle 12.2 is released and we will have to upgrade. And in this blog we are going to talk about upgrading to oracle 12.2 using the dbupgrade utility. Of course the dbua tool is still available and can be also used. Oracle Database 12.1 introduced the Parallel Upgrade Utility, catctl.pl. This utility reduces the total amount of time it takes to perform an upgrade by loading the database dictionary in parallel, and by using multiple…

 
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Mouhamadou Diaw

Migrating from oracle to postgresql with ora2pg

By | Database Administration & Monitoring | 4 Comments

PostgreSQL is one of the most used Rdbms. In this blog we are going to talk about migrating from oracle to postgresql using ora2pg. A previous blog about this topic can be found here. After installing ora2pg tool, we will see how to configure and to run it to migrate our data. We are using an oracle 12.1 database and a postgresql 9.6.2. The server is runing on OEL 7.2 The oracle database and the…

 
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Mouhamadou Diaw

Sharding with Oracle 12c R2 Part II : Scalability and Connections

By | Database Administration & Monitoring | No Comments

In previous blog, we talked about system-managed sharding. We saw how it is possible to create shard databases with Oracle 12c R2. Below we remind the configuration we used. VM sharddemo1: catalog VM sharddemo2: shard VM sharddemo3: shard One of the characteristics of sharding is the scalability, and in this blog we are going to add a new shard on a new server. The new configuration will be like below VM sharddemo1: catalog VM sharddemo2:…

 
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Mouhamadou Diaw

Is your DBA_FEATURE_USAGE_STATISTICS up-to-date?

By | Database Administration & Monitoring | One Comment

Last day we were doing a licensing review for a client. As many dbas may already know, this require to execute some oracle scripts at OS level and database level. Among these scripts we have the script options_packs_usage_statistics.sql (docId 1317265.1) which is an official oracle script to check the usage of separately licensed Oracle Database Options/Management Packs This script is using the DBA_FEATURE_USAGE_STATISTICS table to retrieve info. And sometimes it may happen that data of…

 
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Mouhamadou Diaw

Sharding with Oracle 12c R2 Part I

By | Database Administration & Monitoring | 12 Comments

Oracle 12.2 comes with many new features. In this article we are going to talk about sharding. It is a database scaling technique based on horizontal partitioning of data across multiple oracle databases called sharded databases (SDB). Each shard contains the table with the same columns but a different subset of rows. Sharding can be represented like this For DBA: SDB is in fact multiples databases that can be managed collectively or individually There are…

 
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Mouhamadou Diaw

Dataguard Oracle 12.2: Keeping Physical Standby Sessions Connected During Role Transition

By | Database Administration & Monitoring | One Comment

As of Oracle Database 12c Release 2 (12.2.0.1), when a physical standby database is converted into a primary you have the option to keep any sessions connected to the physical standby, without disruption, during the switchover/failover. When the database is reopened as the primary, the suspended sessions resume their operations as if nothing had happened. If the database (or an individual PDB) is not opened in the primary role, the sessions will be terminated. To…

 
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Mouhamadou Diaw

Database Diagram using SQL Developer

By | Database Administration & Monitoring | No Comments

Last Day a client asked me if I can generate a relational diagram for an oracle schema. He was just preparing a migration and wanted to see how tables are organized in the schema. In this article we will show how this is possible with SQL Developer . We are using SQL Developper 4.1.3.20 Once SQL Developer started just proceed as following : Launch File ==>Data Modeler ==>Import==>Data Dictionary Choose your connection and Click Next…

 
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