Philipp Salvisberg’s Blog
Database-centric development
2023-10-11
1. The Problem I created a Docker image and a container for the Oracle Database 19c (19.19) for Linux ARM. The container contains ORDS, APEX and various sample schemas. Finally, an Oracle database that runs pretty fast on my Apple Silicon machine. Then I built a cold database clone by creating a […]
2023-04-16
Starting Position I got my MacBook Pro 16″ with an Apple M1 Max chip with 10 cores, 64 GB RAM and 4 TB disk in November 2021. At that time, the M1 chip had already been on the market for a year and I knew that there were problems when running virtual […]
2023-03-05
Introduction In the last episode, we extended the IslandSQL grammar covering the complete lock table statement. However, the support for expressions was very limited. It was not possible to use a date literal or to_date function to determine a partition to be locked. Time to fix that. In this episode, we will have […]
2023-02-19
Introduction In the last episode, we extended the IslandSQL grammar to cover all DML statements as a single lexer token. Now it’s time to handle the complete grammar for one DML statement. The simplest one is lock table. A good reason to start with it and lay the foundation for the other DML […]
2023-02-07
Introduction In the last episode, we build the initial version of IslandSQL. An Island grammar for SQL scripts covering select statements. In this blog post, we extend the grammar to handle the remaining DML statements. The full source code is available on GitHub and the binaries on Maven Central. Lexer Changes The […]
2023-02-04
Introduction An island grammar focuses only on a small part of a grammar. The island represents the small, interesting part and the sea the rest. In this blog post, I explain the components of an island grammar for SQL scripts named IslandSQL. In the first iteration, we focus on the select statement. Everything […]
2022-10-30
The Original Problem A customer is currently upgrading some Oracle databases from 11.2 to 19c. One query was extremely slow on the new test system and my job was to find out why. The root cause was that the database parameter optimizer_secure_view_merging was set to a different value. In 19c true and […]
2022-10-11
Background and TL;DR Connor McDonald wrote a blog post named Cleaner DDL than DBMS_METADATA. Back then he asked me if it would be possible to let the formatter remove unnecessary double quotes from quoted identifiers. Yes, of course. Actually, the current version of the PL/SQL & SQL Formatter Settings does exactly that. […]
2022-09-25
Nobody knows what kind of restrictions we will experience later this year. That’s why the DOAG Conference + Exhibition 2022 took place in September instead of November. The organizers wanted an in-person event. While you can access some chosen content remotely an in-person event has a lot of advantages, like getting in […]
2022-07-31
The merge statement allows you to insert, update and delete rows in the target table in one go. This is great. However, the delete part does not work as expected. Is it a bug? No, it works exactly as documented. Nonetheless, I was not aware of this for years. Let’s take a […]