Backend Developer
PostgreSQL and MySQL questions
25 questions on PostgreSQL and MySQL for backend developers, easiest first.
Medium 10
- Benefit of INCLUDE in an indexmedium
- PostgreSQL's default isolation levelmedium
- MySQL InnoDB's default isolation levelmedium
- Case-insensitive lookup ignores the indexmedium
- Phone lookup does a full table scanmedium
- Indexing only the pending ordersmedium
- Pool runs dry after some errorsmedium
- Querying inside a JSONB columnmedium
- Searching article text with LIKEmedium
- A dashboard shows yesterday's totalsmedium
Hard 15
- Workers block each other on a jobs tablehard
- Two doctors go off call at oncehard
- Table bloat that VACUUM will not fixhard
- Index for the few pending rowshard
- Adding an index to a live big tablehard
- A transaction spread across connectionshard
- Features that break behind PgBouncerhard
- Tables grow though rows are deletedhard
- Which new column rewrites the tablehard
- A bad query takes the database downhard
- Deleting old log rows every nighthard
- Two kinds of database timeouthard
- A query with 20,000 ids in IN (...)hard
- Emoji in reviews fail to savehard
- 'José' blocked because 'Jose' existshard