MySQL
Course review: SQL …
Update: Markus was kind enough to comment on my review. Regarding the "minimise the number of tables to limit joins" he said:
it is often the best approach to store some attribute redundant (e.g. normalised as before plus wherever needed). Maintenance of this redundancy should be …
Two less common tricks …
Recently I faced an SQL performance issue. What I wanted to do was rather common: Apply the (set) difference operation on two tables.
In relational algebra, the difference operation applied on two tables A and B gives as a result a new table C that contains all the elements that are in table A but …
In relational algebra, the difference operation applied on two tables A and B gives as a result a new table C that contains all the elements that are in table A but …