Oracle

Upgrade to Oracle 19c – performance issue

In this blog I want to introduce you to a workaround for a performance issue which randomly appeared during the upgrades of several Oracle 12c databases to 19c I performed for a financial services provider. During the upgrades we ran(…)

CLUSTER

By Franck Pachot . Statistically, my blog posts starting with a single SQL keyword (like COMMIT and ROLLBACK) in the title are not fully technical ones, but about moves. Same here.

Oracle ADB from a Jupyter Notebook

By Franck Pachot . My first attempt to connect to an Oracle database from a Jupyter Notebook on Google Colab was about one year ago: https://medium.com/@FranckPachot/a-jupyter-notebook-on-google-collab-to-connect-to-the-oracle-cloud-atp-5e88b12282b0 I’m currently preparing a notebook as a handout(…)

How to synchronize the appliance registry metadata on an ODA?

Databases administration on a Bare Metal ODA will be done as root user by running odacli commands : odacli create-database to create a database odacli upgrade-database to upgrade a database between major releases odacli move-database to move databases from one(…)

Oracle DML (DELETE) and the Index Clustering Factor

As a consultant working for customers, I’m often in the situation that I have an answer to a problem, but the recommended solution cannot be implemented due to some restrictions. E.g. the recommendation would be to adjust the code, but(…)

Troubleshooting performance on Autonomous Database

By Franck Pachot . On my Oracle Cloud Free Tier Autonomous Transaction Processing service, a database that can be used for free with no time limit, I have seen this strange activity. As I’m running nothing(…)

Oracle Database Appliance and CPU speed

Introduction A complaint I heard from customers about ODA is the low core speed of the Intel Xeon processor embedded in the X8-2 servers: Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz. 2.30GHz only? Because of its comfortable number of cores(…)

Merge-Statement crashes with ORA-7445 [kdu_close] caused by Real Time Statistics?

In a recent project we migrated an Oracle database previously running on 12.1.0.2 on an Oracle Database Appliance to an Exadata X8 with DB version 19.7. Shortly after the migration a merge-statement (upsert) failed with an ORA-07445: exception encountered:(…)

The myth of NoSQL (vs. RDBMS) “a simpler API to bound resources”

By Franck Pachot . NoSQL provides an API that is much simpler than SQL. And one advantage of it is that users cannot exceed a defined amount of resources in one call. You can read this in(…)

Oracle ASH SQL_PLAN_LINE_ID in adaptive plans

There are several methods to find out where time is spent in an execution plan of a query running in an Oracle database. Classical methods like SQL Trace and running a formatter tool like tkprof on the raw trace, or(…)