StackPilot comparison
PostgreSQL vs MongoDB: Which Database Should You Choose?
Compare PostgreSQL and MongoDB by data model, transactions, queries, scalability and startup use cases.
Short answer
PostgreSQL is a strong default for relational SaaS data. MongoDB can be a better fit when document-oriented data and access patterns make its model simpler.
Choose the first option for
Relational SaaS, reporting, transactions and complex relationships
Choose the second option for
Document-oriented applications and flexible schemas
At a glance
| Factor | Option A | Option B |
|---|---|---|
| Model | Relational | Document |
| Query language | SQL | MongoDB query language |
| Transactions | Strong relational transactions | Multi-document transactions available |
| Schema | Structured | Flexible document structure |
| Best default for SaaS | Usually | Depends on data model |
Start with your data model
If your product has users, organizations, subscriptions, permissions and invoices, relationships are first-class data. PostgreSQL makes those relationships explicit and queryable.
MongoDB can be excellent when documents are naturally accessed together and a flexible document model reduces application complexity.
Do not choose based on theoretical scale
Most startups need a database that is easy to model, back up, query and operate long before they need exotic scaling. Choose the system your team can maintain and measure.
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