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Database

Everything our consultants learn while running databases for customers: Oracle, PostgreSQL, SQL Server, MySQL, MariaDB, MongoDB and Delphix. Expect hands-on posts about installation, day-to-day administration, backup and recovery, performance tuning, replication and upgrades.

EDB BART 2.0 – How to upgrade and block level incremental backups

We already have some posts on how you can use EDB BART to backup and restore your PostgreSQL instances from one central server (EnterpriseDB Backup and Recovery Tool (BART), getting started with postgres plus advanced server (2) – setting up a backup and recovery server). The current version you can download from the EnterpriseDB website is 1.1 but version 2.0… 

Google Cloud Platform instances and Oracle Database

By Franck Pachot . When it comes to choose a cloud instance to run Oracle Database, you want to be able to run your workload on the minimum CPU cores. This is why in a previous post I measured how many logical reads per seconds can be achieved with a SLOB workload, on AWS which is often the first considered,… 

Is it the right time to move to MariaDB now?

Do you think about adding MariaDB to your database landscape or do you even think about replacing other database systems with MariaDB? Then you should register here. We will be doing a webinar with MariaDB on Thursday, the 23rd of March. The title is: “Why it is a good time to move to MariaDB now” and after a short introduction… 

12cR2: TNS_ADMIN in env.ora

By Franck Pachot . The network files (sqlnet.ora, tnsnames.ora, lsnrctl.ora) are read by default from ORACLE_HOME/network/admin but you may have several Oracle installations, and want only one place for those files. Then you can use TNS_ADMIN environment variable. But are you sure that it is always set when starting the database? the listener? the client? They must be consistent (see… 

Oracle 12cR2, RAC, Cloud, ACFS, PDB thin clones and asmadmin

By Franck Pachot . In the Oracle Public Cloud, fast provisioning gets all its meaning when creating a RAC database service: in one hour you can get an operational highly available multitenant database. You can even create it in Data Guard for Disaster Recovery. Now, Oracle is pushing ACFS to store the datafiles rather than direct ASM. Especially in multitenant… 

Oracle 12cR2: changes for login.sql

By Franck Pachot . If you use a login.sql script to set the SQL*Plus environment from your current working directory, you will see that it will not run anymore in 12.2. This is a security feature, and a good occasion to explain how sqlplus finds the scripts to run, on Linux. For my test, I have login.sql, LOGIN.SQL, and script.sql… 

Misleading wait event names clarified in V$EVENT_NAME

By Franck Pachot . The oracle wait event names were originally implemented for the oracle rdbms developers and are now use by the database users to troubleshoot performance issues. The consequence is that the name may be misleading because they have a meaning from the internal point of view. Here is some clarification about them. In 12c the clarification is… 

ODA – 32GB template but got a database with 16GB SGA???

I got an interesting question today from a customer which created a database on ODA. He selected the template odb-04 which shows 32GB Memory but got a database with a 16GB SGA… Is it due to the PGA size, a limitation in the system, the huge pages usage which is reached or even a bug? Indeed, the answer is easier… 

Purging Unified Audit Trail in 12cR1

By Franck Pachot . When you want to empty a table you have two methods: delete and truncate. If, for any reason (see previous post) the Unified Audit Trail has become too big, you cannot directly delete or truncate the table. You must call the dbms_audit_mgmt.clean_audit_trail. But then you want to know if it will do slow deletes or quick… 

Is your DBA_FEATURE_USAGE_STATISTICS up-to-date?

By Mouhamadou Diaw 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… 

Speaking at the next SQL Nexus at Copenhagen 2017

On May 2nd, I will have the chance to speak during the next SQL Nexus event in Copenhagen (1 -3 may) about SQL Server 2016 and availability groups and if I have enough time, you will see what is coming with the SQL Server vNext. This is also a good opportunity to attend to other sessions held by well-known people… 

Oracle 12c – Is VKTM always your top process?

By William Sescu If VKTM is always your top cpu consuming process, then this blog might be something for you. Especially in virtual environments, I have seen often the VKTM process as the top process, even if the VM was idle. So, I am burning CPU without any obvious benefit. So what is the reason for the high CPU consumption?…