Category Archives: Databases

#Oracle: #SQL to get the latest executed queries in a schema

By | February 20, 2021

I was trying to obtain the last executed query on an Oracle instance. Seems easy but I wanted also: to exclude the queries that are done by sys user as maintenance to focus on queries executed by a specific client type. The best way to do it is to use the V$SQLAREA system table. V$SQLAREA… Read More »

Migrating a #PostgreSQL database to a diferent PostgreSQL version or to a restrictive Postgres instance of cloud providers like #AWS-RDS

By | December 11, 2019

There are instances when one needs to migrate data from a Postgres database to a different PostgreSQL database version or even worse to a restrictive PostgreSQL instance of cloud providers like #AWS-RDS. When migrating to a different version of Postgres after you used to run on a frozen production version for long time it may… Read More »

Migrate legacy application using Oracle 10g to Oracle 12c

By | March 16, 2019

After upgrading my developement Oracle database to 12c I discovered that an old legacy application still under support was no longer working throwing the following Oracle error: After some digging I found the following reported bug: Bug 14575666 In 12.1, the default value for the SQLNET.ALLOWED_LOGON_VERSION parameter has been updated to 11. This means that… Read More »

Investigate #Oracle #deadlocks

By | May 10, 2018

Sometimes we may end up having some application resources competing for the same resource on our Oracle database. This is usually the case when some exclusive resource must be allocated or updated as in the case of database based locking mechanisms. If there are code issues we may end up in a deadlock situation when… Read More »