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.
By Franck Pachot . By a strange coincidence, I’ve encountered several cases of long parse time recently. That was the occasion to give a closer look at a CBO trace enhancement that came with April 2016 PSU: Bug 16923858 Diagnostic enhancement to annotate 10053 trace with accumulated parse time I have a query that takes several seconds to parse and…
By Franck Pachot . The separation of roles between system DBA and application DBA is the way to go for agile development and the PDBaaS managed service is an excellent way to play with this concept: You are PDB administrator but not the CDB administrator. Here is an example about tablespace creation/deletion, and the kind of problems that may arise…
By Mouhamadou Diaw 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…
By Franck Pachot . The Exadata Express Cloud Service is a managed PDBaaS: Oracle is the system admin and the CDB database administrator, you are the PDB administrator. You connect with a local user, PDB_ADMIN, which is no SYSDBA privilege but has a PDB_DBA which has nearly all DBA rights, but with some features disabled by lockdown profile. I have…
It has been quite a while since the last posts in this series, so here is what we looked at until now: Can I do it with PostgreSQL? – 1 – Restore points Can I do it with PostgreSQL? – 2 – Dual Can I do it with PostgreSQL? – 3 – Tablespaces Can I do it with PostgreSQL? –…
By Franck Pachot . When you run Oracle Database on Amazon AWS you Bring Your Own Licenses depending on the number of virtual cores (which are the number of cores allocated to your vCPUs). Behind the instance types, you have different processors and hyper-threading. Then, when choosing which instance type to run, you want to know which processor offers the…
On my first blog about SQL Server on Linux, I introduced the new high availability feature which concerns only SQL Server failover cluster instances so far. During this discovery time, I had the support of Mihaela Blendea (@MihaelaBlendea) at Microsoft to clarify some architecture aspects about this new kind of architecture. Firstly, I would like to thank her. It’s always a…
By Franck Pachot . Oracle Database licensing can be based on two metrics: Processor or Named User Plus (NUP). NUP also necessitate to count the processors because there is a minimum number of NUP per processor. Then it is very important to know how to count processors. The time where a machine had 1 socket with 1 processor with 1…
By William Sescu There are some articles floating around how to prevent a license violation with Active Data Guard. Some of them related to an underscore parameter “_query_on_physical” and some of them related to a startup trigger. Both of them have advantages and disadvantages. E.g. regarding the “_query_on_physical” I can’t find any MOS Note about it, and I don’t know…
By Mouhamadou Diaw In this blog we are going to talk about a nice extension in PostgreSQL: temporal_tables. This extension provides support for temporal tables. What is a temporal table? Just a table that tracks the period of validity of a row. When implemented, this feature allows you to specify that old rows are archived into another table (that is…
Last week in the first part of this blog we have seen a short introduction how to setup an Oracle Infrastructure with Vagrant and Ansible. Remember all the files for this example are available here https://github.com/nkadbi/oracle-db-12c-vagrant-ansible Get the example code: git clone https://github.com/nkadbi/oracle-db-12c-vagrant-ansible If you have prepared your environment with Ansible, Vagrant and Oracle Virtual Box installed – and provided…
By William Sescu I am planning to backup my 12R2 container database, because a huge application change is coming up, and I want to be sure that I have a good RMAN backup beforehand. For that particular DB, I want to do it with a cold backup in combination with RMAN tags. Unfortunately I don’t have any backups at the…
