Overview
This article explains the differences between Big Tables and External SQL sources (such as PostgreSQL) and when to use each option.
Big Tables store all data inside Glide.
External SQL sources store data outside of Glide and require network communication for every read and write.
Big Tables
Big Tables are the recommended data source for most apps because they provide:
Fast performance
Data is stored inside Glide’s data center, so there are no external network hops.
High reliability
Glide manages replication, caching, and storage internally.
Full feature support
All Glide features, including computed columns, relations, and actions, work with Big Tables.
Consistent writes and predictable sync behavior
Updates remain within Glide, so sync performance is stable.
Big Tables represent the direction of Glide’s platform development.
External SQL Sources
External SQL sources use your own database (e.g., PostgreSQL). These sources have important limitations:
Network latency
Every request travels from the device → Glide → your SQL server → Glide → device.
This makes reads and writes slower than Big Tables.
Variable performance
Speed depends on your hosting provider, server location, and network reliability.
Feature differences
Some Glide features do not work with external data or behave differently because the data does not live in Glide.
Enterprise requirement
External SQL sources require a Glide Enterprise plan.
External SQL is best when your data must stay in an external system of record.
When to Use Each Option
Use Big Tables when:
You want the fastest performance.
You want full compatibility with Glide features.
You want predictable sync times.
You are migrating from another Glide data source.
Use External SQL sources when:
Your organization already maintains a SQL database as its source of truth.
You need to run database operations outside of Glide.
You must store data in your own infrastructure for compliance reasons.
Most teams migrate to Big Tables first because this provides immediate performance improvements and aligns with Glide’s long-term architecture.