Track · Intermediate

Postgres for App Developers

4 lessons42 min total

You do not need to become a DBA. You do need to know why a query got slow, what an index can and cannot do, and which schema change will lock a table in production. That is what this track covers.

LevelIntermediate
Lessons4
Total time42 minutes
CostFree, no signup

Before you startWhat you should already know

  • You can write a JOIN
  • You have a database that is starting to feel slow

Curriculum4 lessons, in order

  • How indexes actually work

    A B-tree index is a sorted structure, and every rule about when it helps follows from that one fact.

    12 min

  • The N+1 problem

    The most common performance bug in application code, why ORMs make it invisible, and the three ways out.

    9 min

  • Transactions and the lost update

    Read committed is the default and it does not do what most people assume. Here is the bug that follows from that.

    11 min

  • Migrations that do not take the site down

    Some schema changes are instant. Some rewrite the whole table while holding a lock that blocks every read. Knowing which is which is the job.

    10 min