What is B-Tree Index?
The default balanced-tree structure making equality and range lookups fast without scanning every row. Add one where queries filter, join, or sort — then confirm with EXPLAIN before assuming victory.
Related terms
Composite Index
One index spanning several columns for queries that always filter them together, ordered most-selective first. A three-column composite beats three single-column indexes on the same query shape.
Partial Index
An index covering only rows matching a predicate, such as live subscriptions where status is active. Smaller, faster, and cheaper to maintain than indexing rows queries never touch.
EXPLAIN Query Plan
The command prefix showing how the database will execute a query: scan types, index usage, join order, and row estimates. Reading plans separates “add an index” guesses from evidence about what the planner actually does.
Unique Constraint vs Index
A uniqueness guarantee enforced by the database versus a lookup accelerator with no such promise. Postgres implements unique constraints with an index, but only the constraint rejects duplicates.
Connection Pooling
Reusing a small set of open database connections across many requests instead of dialing fresh each time. Pools cap concurrency, cut handshake latency, and keep serverless bursts from overwhelming Postgres.
PgBouncer & Supavisor
Lightweight proxies that multiplex thousands of app connections onto a handful of real Postgres sessions. Supavisor is Supabase’s managed pooler; PgBouncer is the self-hosted original both patterns descend from.