by Javier Morales Carreras | Mar 2, 2024 | Database
In 2019 they decided in Chile that the winter time adjustment would be 5 months, instead of the usual 3 months. Morocco also decided to move its time with respect to GMT from +00 to +01. These changes that you may think do not affect you in the least, unless you live...
by Javier Morales Carreras | Jan 25, 2024 | Database
This year 2024 is a leap year. SQL> SELECT LAST_DAY(TO_DATE(’01/02/2024′,’DD/MM/YYYY’)) FECHA FROM DUAL; FECHA —————————– Thursday, 29 February 2024 In fact, each year divisible by four is a leap year, but throughout history many adjustments occurred to the...
by Javier Morales Carreras | Oct 11, 2023 | GitHub projects
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...
by admin | May 31, 2023 | Off Topic
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...
by Javier Morales Carreras | May 19, 2023 | Off Topic
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. But, what is a Hackathon? It is a kind of technological...
by Javier Morales Carreras | Mar 14, 2023 | SQL
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...
by Javier Morales Carreras | Mar 10, 2023 | SQL
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...
by Javier Morales Carreras | Mar 7, 2023 | 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...
by Javier Morales Carreras | Mar 2, 2023 | GitHub projects
As every year, it’s time to clean up the databases Marie Kondo style. Database administrators have to historicize, compress or delete old partitions that are no longer needed. Obviously, partitioned tables (and their local indexes) are the best place to...
by Javier Morales Carreras | Jan 22, 2023 | GitHub projects
Let’s talk about physical backups and how to get a report based on your own “safety criteria” about the successfull backups needed to ensure a safe recovery scenario. In many places, they get reports when backups end successfully, or sometimes only...
