Category: SQL 201
Your database doesn’t just contain your data. It also contains data about your data.
Before you rage quit or call in your DBA, check these things aren’t slowing down your SQL query. A few tweaks could be all you need to get things working.
A high-level overview of why your DBA needs to VACUUM your tables
Your query is running slow, have you checked your indexes?
CTEs are persisted temporary data sets, that allow you to store a single query to go back to later in your script.