Review Glossary FR

Size

Eyes

Finish a part in any dojo to unlock the next eyes.

Know what your database does, ten minutes a day.

One chapter a day, on real open-source code. Questions you get right come back 1, 3, 7, 21 and 45 days later.

Today · day 1 · 10 min

Why use a database instead of a file
Start reading →

0 of 40 chapters done

Data and questions: 0 of 8Inside the engine: 0 of 8Many at once: 0 of 8Keeping it running: 0 of 8Beyond one server: 0 of 8
One pillar per part. It fills as you finish its chapters.

The path

Data and questions: 0 of 8Data and questions

  1. Why use a database instead of a file 1
  2. Tables, rows and keys 2
  3. Asking with SELECT 3
  4. Joins 4
  5. Counting with GROUP BY 5
  6. NULL in SQL: comparisons, NOT IN and unique keys 6
  7. Normalization 7
  8. Denormalization: copying data on purpose 8

Inside the engine: 0 of 8Inside the engine

  1. Pages and rows on disk 9
  2. B-tree indexes 10
  3. Index types: GIN, GiST, BRIN and Hash 11
  4. Reading EXPLAIN 12
  5. Planner statistics: how PostgreSQL estimates rows 13
  6. Composite, partial and covering indexes 14
  7. The write-ahead log 15
  8. Dead rows and VACUUM 16

Many at once: 0 of 8Many at once

  1. Transactions and savepoints 17
  2. MVCC: row versions and snapshots 18
  3. Isolation levels 19
  4. Locks and deadlocks 20
  5. Optimistic locking 21
  6. Constraints: UNIQUE, CHECK and exclusion 22
  7. Upserts and safe retries 23
  8. A job queue in the database 24

Keeping it running: 0 of 8Keeping it running

  1. Connections and pooling 25
  2. Migrations that lock the table 26
  3. Backups you can restore 27
  4. Replication and lag 28
  5. Failover without split brain 29
  6. Finding slow queries 30
  7. N+1 and the ORM 31
  8. Roles, grants and row-level security 32

Beyond one server: 0 of 8Beyond one server

  1. Partitioning big tables 33
  2. Sharding 34
  3. Key-value stores 35
  4. Documents and JSONB 36
  5. Full-text search 37
  6. Columns for analytics 38
  7. How replicas agree 39
  8. Capstone: the data of a shop 40