TOPIC / CATEGORY
Notes in Databases
5 articles
Use EXPLAIN ANALYZE Without Surprises
Read a real PostgreSQL query plan while limiting runtime risk and remembering that ANALYZE executes the statement.
One Slow MySQL Query and the Index It Wanted
Read MySQL 8 EXPLAIN output for one slow query, choose composite index column order, make the index covering, and retire unused indexes safely by making them invisible first.
RDB, AOF, Both, or Neither: Redis Persistence on a Small Server
Decide whether a small Redis needs RDB snapshots, an append-only file, both, or no persistence, check that saves are really happening, and prove a restore with a throwaway instance.
PostgreSQL Memory Settings on a Small VPS
Check and size sharedbuffers, effectivecachesize, workmem, maintenanceworkmem, and maxconnections on a small server, apply them with the right reload or restart, and confirm the effect.
Redis maxmemory and Eviction on a Small Server
Set a Redis memory limit, choose an eviction policy that matches what the keys are for, and use INFO to tell whether Redis is evicting keys or refusing writes.