Category Archives: Databases

#Oracle ORA-00600: internal error code, arguments: [ktbdchk1: bad dscn]

By | November 2, 2021

Oracle 11g database with Data Guard active. A switch of the sites (from production to disaster recovery node) is done and all seems good. Suddenly one day after the switch (more than one month) the enterprise application using it cannot connect any-more (connection pool getting filled up). The underlying issue that causes this is reported… 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 »