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PostgreSQL Labs

PostgreSQL Labs

Table of Contents

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Query planning: EXPLAIN / EXPLAIN ANALYZE
Index design and trade-offs (composite indexes, index-only scans)
JSONB and GIN indexing patterns
Locking and concurrency diagnostics
Practical performance workflows (plan → hypothesis → change → validate)

Labs
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Below are the PostgreSQL labs available on this site.

PostgreSQL Index vs Full Scan: EXPLAIN ANALYZE on 100k / 1M / 5M Rows (Filter + ORDER BY + LIMIT)

7 February 2026·1832 words·9 mins

Guides PostgreSQL Performance Postgresql Performance Index Explain Sql Database

A reproducible lab showing how a composite index changes the execution plan from (parallel) seq scan + sort to index scan + limit, with EXPLAIN (ANALYZE, BUFFERS) evidence on 100k/1M/5M rows.

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