My question is simple, currently, I have a database with an “User” table which contains important information about each users (email, username, password), an “Identity” table which contain the first name, last name, birthday… of an user, and a “Medias” table which cu…
Tag: optimization
Optimization of BigQuery aggregated data between two dates
I’m trying to compare the result of one query (example: number of rows), between the beginning of the current month and the current date, compared to what happened the previous month. Example: Today is 25/01, so I’d like to know the number of rows created between the 01/01 and 25/01, vs the previo…
How to run OPTIMIZE TABLE with the least downtime
I have a MySQL 5.5 DB of +-40GB on a 64GB RAM machine in a production environment. All tables are InnoDB. There is also a slave running as a backup. One table – the most important one – grew to 150M rows, inserting and deleting became slow. To speed up inserting and deleting I deleted half of the …
How to get second-highest salary employees in a table
It’s a question I got this afternoon: There a table contains ID, Name, and Salary of Employees, get names of the second-highest salary employees, in SQL Server Here’s my answer, I just wrote it in …