Hasura - CockroachDB Compatibility
Introduction
As CockroachDB supports PostgreSQL, the way it functions with Hasura is also very similar. However, there are a few incompatibilities to be aware of.
Incompatibilities and unsupported features
The most up-to-date list of unsupported Postgres features can be found on the CockroachDB website.
Currently, the following features are supported with CockroachDB and Hasura:
Queries
Queries are fully supported except for queries containing distinct_on arguments, see issue, but please note that GraphQL key
ordering in JSON objects is not guaranteed. This is because CockroachDB implements the JSONB variant of the Postgres
JSON types, which do not preserve key ordering.
Please also note that SERIAL columns will produce numbers that overflow JavaScript numbers. These will need special
treatment by either enabling the
HASURA_GRAPHQL_STRINGIFY_NUMERIC_TYPES environment variable or
bespoke JSON parsing client-side.
Tables
Querying from all kinds of tables and views is currently supported. This includes local, reference, and distributed tables. All the tables can be tracked from the Hasura Console.
Relationships
The following table describes the supported relationships based on the supported joins in CockroachDB:
| To Local | To Reference | To Distributed | |
|---|---|---|---|
| From Local | Object, Array | Object, Array | |
| From Reference | Object, Array | Object, Array | |
| From Distributed | Object | Object, Array |
The Hasura Console allows you to add all the supported relationships.
Permissions
All permissions work on CockroachDB like on Postgres without any restrictions.
Functions
CockroachDB, and therefore Hasura, does not yet support user-defined functions (UDFs) on a stable release. However, UDF support has recently been added to CockroachDB Beta (see issue), so watch this space!
Mutations
Mutations are supported in GraphQL Engine with the exception of fetching relationship data as part of returning. This
is not yet supported.
Subscriptions
Live Queries and Streaming Subscriptions are supported with CockroachDB.
Event triggers
CockroachDB does not yet support creating triggers (see issue) on reference tables. Hence, this is currently not supported.
Naming conventions
Naming conventions are currently only implemented as an experimental feature on Postgres sources. See docs.
