Introduction DML WAIT[NOWAIT], introduced in 23.26.2.0.0, helps to specify how long a DML statement should wait to acquire a lock before rolling back the DML statement and returning session control to the user. The general syntax is: You can specify whether to wait forever, not at all or for n seconds, milliseconds or microseconds. The […]
Introduction In a relational database, defining constraints can help ensure data integrity, improve data consistency, enhance SQL query performance, and, in the case of foreign keys, ensure referential integrity. I talk a lot more about constraints in a previous post about database constraints. In a separate post, I also talk about locks and transaction concurrency
With the release of Oracle Database 23.26.2.0.0, A new join syntax JOIN TO ONE has been introduced. It’s meant to simplify the FROM clause and prevent duplicates that may arise from join conditions. This post explores this new feature and explains how it can be of help when writing SQL queries.
Imagine that at your local superstore(Walmart, Target, etc.), when you got to the parking lot, you had to get a number and wait till you got called to proceed into the store to do your shopping(however long that takes) and then leave, consequently freeing up space for the next person to come in. This sounds
Background One of the best resources for anyone who’s into oracle tech is this site called the devgym. It contains games, quizzes, classes and workouts all designed to help build developers’ Oracle Database, SQL and PL/SQL muscles for FREE! I visit this site often to play the speed SQL and SQUIZL games and sometimes the
INTRODUCTION I was recently confronted with an error ORA-01502 error. This occurred as I was attempting to perform a DML operation on a table. Initially, I was surprised but after some digging I managed to get to the bottom of the issue. Here’s what happened. SETUP Firstly, we create a sample table, create a unique
A bit of Background I have been reading a lot about autoupgrade. I see lots of oracle technologists talking about it on their blogs and videos and they recommend it. Having got tired of watching from the sidelines, wondering what all the fuzz is about and also due to my own enormous FOMO, I decided
Most data problems don’t come from bad SQL — they come from bad assumptions. And the worst one is believing that constraints can be “handled in the application.” They can’t. They never could. The moment data is touched by an ETL job, a script, an integration, a migration, or a future rewrite, every application‑level rule evaporates. The database is the only place where integrity actually persists. Datatypes, keys, foreign keys, checks, and assertions aren’t optional features — they’re the backbone of reliable systems. If the data matters, the constraints belong in the database. Full stop.
Everyone has a pattern or writing style when it come to SQL I’ve noticed. Some people use uppercase for keywords other people don’t, some start a column on a new line others don’t, people format differently, leaving commas at the end of the line vs at the beginning and many more niche ways people write.
BACKGROUND Consider this post from stackoverflow. As seen above, Nesting of with clauses is not possible in oracle and while the examples in the answer are simple and straightforward allowing you to define multiple different subqueries, sometimes (and I know because I’ve been there) you actually need to or at least wish you would nest
