Citus Workbench

A workbench for Citus.

This repository includes:

• Test fixtures for starting Citus using Testcontainers
• Integration tests working with Citus using raw SQL statements
• Integration tests working with Citus using EF and proper modeling to support migrations + distribution

Run The Tests

cd tests

# EF based tests
dotnet test --filter CitusEfTests

# Direct SQL tests
dotnet test --filter CitusDirectSqlTests

# EF based test with migrations
dotnet test --filter CitusDealershipTests

Key Concepts

• Distribution Key. This is the shard key that is used to determine which shard that a record will be located in. In this example, we build an app for schools and thus we want to use the district_id. This field must:
  • Be included with every record that should be co-located
  • Included on the primary key of the record
  • Included on indexes
  • Included in FK references

Notes

# To force remove a migration (not connected to DB)
dotnet ef migrations remove --force

TODO

• Auto generate idempotent distribution statements using source generators
• Auto generate reference table statements using source generators
• Implicitly generated reference tables for M2M
• Inclusion of the distribution key into all queries (problematic for Prisma without it since the majority of queries are schema-based(easier for EF because of global query filters?))
  • Global query filters need to be tested for navigation properties

Resources

• Single Node Citus
• Citus in Cluster
• Citus in Cluster (Compose)