Oracle

A Serverless Standby Database called Oracle Autonomous Data Guard

By Franck Pachot . Announced by Larry Ellison last week, here it is: the Autonomous Data Guard. You can try it, unfortunately not on the Free Tier. First you create an Autonomous Database (ATP or ADW) and then(…)

19c: scalable Top-N queries without further hints to the query planner

By Franck Pachot . The FETCH FIRST … ROWS ONLY syntax arrived in Oracle 12c and is much more convenient than using a subquery with ‘ORDER BY’ wrapped in a “WHERE ROWNUM < …” around it. But as I(…)

Documentum – DARs installation fails Java 11

As you probably heard if you weren’t in an underground bunker for the past 2 years, Oracle changed the licensing of the Oracle JDK. If you want to read more about it, there is a good FAQ(…)

Oracle ACFS: “du” vs. “df” and “acfsutil info”

By Franck Pachot . This is a demo about Oracle ACFS snapshots, and how to understand the used and free space, as displayed by “df”, when there are modifications in the base parent or the snapshot children. The important(…)

POUG 2020 Workshop Day 1

I had the opportunity to participate to POUG day 1 and wanted through this blog to share some of my feedback on the interesting sessions I could follow. First of all, I would like to mention the great introduction done(…)

The Oracle ACE program ♠ what it is not ♠

By Franck Pachot . I had a few questions about the Oracle ACE program recently and I thought about putting some answers there. Of course, that’s only my point of view, there’s an official web page:(…)

Some myths about PostgreSQL vs. Oracle

By Franck Pachot . I originally wrote this as a comment on the following post that you may find on internet: https://www.2ndquadrant.com/en/blog/oracle-to-postgresql-reasons-to-migrate/ but my comment was not published (many links in it… I(…)

Oracle non-linguistic varchar2 columns to order by without sorting

By Franck Pachot . Sorting data is an expensive operation and many queries declare an ORDER BY. To avoid the sort operation you can build an index as it maintains a sorted structure. This helps with Top-N queries as(…)

No{Join,GroupBy}SQL – Analytic Views for BI

By Franck Pachot . Advocates of NoSQL can query their structures without having to read a data model first. And without writing long table join clauses. They store and query a hierarchical structure without the need to follow relationships,(…)

Oracle 12c – global partial index

By Franck Pachot . We have an incredible number of possibilities with Oracle. Yes, an index can be global (indexing many partitions without having to be partitioned itself on the same key) and partial (skipping some of the table(…)