The Oracle DB maintains some information either on block or on row level ([NO]ROWDEPENDENCIES). dbaora.com/ora_rowscn-nor… The default (NOROWDEPENDENCIES) may cause ORA-08177: can't serialize access for this transaction even if there is no problem on row level.

Just announced new training dates. There are still seats left in my next performance training in April. The remaining courses take place in fall. winand.at/sql-training/o…

Have finished reading the "SQL performance explained" book from Markus Winand (creator of the use-the-index-luke.com). Have already known about indexes and B-trees, but the book helped to understand how they affect SQL operations under the hood. Highly recommend!

There is currently some fuzz about the performance of subqueries vs with clause. Here is my take on it: modern-sql.com/feature/with/p…

The WITH clause is useful to write readable SQL. modern-sql.com/use-case/liter…

Learn once, benefit forever. These SQL courses take experienced developers a leap forward. Starting on September 10th! winand.at/en/newsletter/…

In the meanwhile enjoy a discount for SQL Performance Explained if you don't have it yet: 15YrsAnniversary Only valid when purchasing directly from me (not on Amazon, ...): sql-performance-explained.com (but valid for all languages — see language selection at the top).

TIL about Index-Only Scan for databases ✨ Also I'm in love with this website use-the-index-luke.com/sql/clustering…

SQL Best Practices Every Java Engineer Must Know foojay.io/today/sql-best… [IMHO: not just Java Engineers]

For this WHERE, what index to create? WHERE subsidiary_id = 42 AND last_name LIKE '%INA%' Is (subsidiary_id) enough or should it be (subsidiary_id, last_name)? use-the-index-luke.com/sql/clustering…

At about this time of the day, I run my open-to-everyone trainings. The last training this year is "SQL Performance Explained", for which I have one spot left. It starts Dec 2nd and is delivered in seven 2-hour long in-person sessions each Mon/Wed/Fri. winand.at/sql-training/o…

Improved RCSI Ghost Cleanup in SQL Server 2022 — by Paul White As always, Paul provides deep insight into the SQL Server implementation. sql.kiwi/2024/12/improv…

Survey on performance optimization for database systems (2023) researchgate.net/publication/36…