> ## Documentation Index
> Fetch the complete documentation index at: https://docs.streamnative.io/llms.txt
> Use this file to discover all available pages before exploring further.

# SQLCatalog Schema Support

> Review the topic schemas supported by SQLCatalog source discovery during Private Preview.

During Private Preview, SQLCatalog source discovery supports only Avro topics for both Pulsar and Kafka.

<Note>
  This compatibility matrix describes which topics are eligible for automatic source discovery. Query behavior for a discovered source is determined by the SQLWorkspace engine.
</Note>

| Schema          | Pulsar        | Kafka          |
| --------------- | ------------- | -------------- |
| Avro            | Supported     | Supported      |
| Boolean         | Not supported | Not applicable |
| Bytes           | Not supported | Not applicable |
| Date            | Not supported | Not applicable |
| Double          | Not supported | Not applicable |
| Float           | Not supported | Not applicable |
| Instant         | Not supported | Not applicable |
| Int8            | Not supported | Not applicable |
| Int16           | Not supported | Not applicable |
| Int32           | Not supported | Not applicable |
| Int64           | Not supported | Not applicable |
| JSON            | Not supported | Not supported  |
| KeyValue        | Not supported | Not applicable |
| LocalDate       | Not supported | Not applicable |
| LocalDateTime   | Not supported | Not applicable |
| LocalTime       | Not supported | Not applicable |
| Protobuf        | Not supported | Not supported  |
| Protobuf Native | Not supported | Not applicable |
| Schema-less     | Not supported | Not supported  |
| String          | Not supported | Not applicable |
| Time            | Not supported | Not applicable |
| Timestamp       | Not supported | Not applicable |

Kafka Schema Registry does not define separate primitive schema types. A primitive value encoded with Avro is classified as Avro; a raw or schema-less Kafka value is not supported. For schema definitions, see [Kafka Schema Registry](/cloud/governance/kafka-schemas/kafka-schema-registry) and the [Apache Pulsar SchemaType reference](https://pulsar.apache.org/api/client/4.0.x/org/apache/pulsar/common/schema/SchemaType.html).

## Source requirements

* A Pulsar topic must be persistent and use an Avro schema.
* A Kafka topic must have an Avro value schema in Schema Registry.
* Topics with an unsupported schema or no schema are skipped during discovery.

For how supported topics become managed sources, see [Source Discovery](/sql/overview/source-discovery).

## Schema changes

Source discovery does not automatically rebuild an existing managed source after its upstream schema changes. Review and manage the existing engine object separately when a schema changes.