Dev Tools · 1h ago
MongoDB vs DocumentDB: Trade-offs in $lookup Join Strategies
A developer compares how MongoDB and DocumentDB for PostgreSQL handle $lookup joins, using a 5-million-document portfolio collection joined to a 5-document exchange rate table. The analysis reveals that document databases perform fewer joins due to embedding, but flexible field semantics like arrays restrict join algorithms. The tests, run in Docker with default settings, illustrate relative costs rather than absolute performance.
Meridian48 take
The post offers a practical, nuanced look at join optimization in document databases, but its Docker-based timings are far from production benchmarks.
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$lookup join strategies: understanding the trade-offs with flexible documents →
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