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The Café Database Blog
A chain of synonyms #JoelKallmanDay
This one is about bad practices. The use of synonyms. If you have felt a cold sweat, you probably experienced something similar. Many users want to access application tables "transparently." Note that I put it in quotes because calling "transparent" "without prefixing...
UN World Innovation Day Hackaton – Projects and teams
On May 12, a five-day Hackathon was held on the occasion of the World Innovation day of the United Nations. I had the honor of mentoring the participating teams. During this time they had to come up with an app that would provide an improvement for the world. Various...
UN World Innovation Day Hackaton – Mentor
On May 9 I received an email from the organization of the #WorldInnovationDay Hack 2023 confirming that they had appointed me as a mentor for the Hackathon to be held from May 12 to 15. I mean, that same week.
Indexing columns with non pure functions
When you filter a column using a function, the optimizer does not use the indexes on that particular column because the function "transforms" the values and makes the index non useful to get the proper ROWIDs. To get around that hurdle, Oracle has function-based...
Unordered sorts
For the result of an SQL query to be ordered, the only valid clause is ORDER BY. Oracle only guarantees the ordered return of rows when ORDER BY is set as the sort criteria. I have repeated these two phrases like a mantra thousands of times. Any other way to get the...
The 7 most common errors in Oracle19c GoldenGate
When you first start a replication deployment with Oracle GoldenGate, it's easy that you miss one or several steps that lead you so some errors. Sometimes, the error message in GoldenGate is not so descriptive, or the implications within are not so clear, so here I...