README - Cadence — ContextQMD

What

This directory contains the cassandra schema for every keyspace that cadence owns. The directory structure is as follows

./schema
   - visibility/           -- Contains schema for visibility data models
   - cadence/              -- Contains schema for default data models
        - keyspace.cql     -- Contains the keyspace definition
        - schema.cql       -- Contains the latest & greatest snapshot of the schema for the keyspace
        - versioned
             - v0.1/
             - v0.2/       -- One directory per schema version change
             - v1.0/
                - manifest.json   -- json file describing the change
                - changes.cql     -- changes in this version, only [CREATE, ALTER] commands are allowed

How

Q: How do I update existing schema ?

Add your changes to schema.cql
Create a new schema version directory under ./schema/keyspace/versioned/vx.x
- Add a manifest.json
- Add your changes in a cql file
Update the unit test within ./tools/common/schema/updatetask_test.go TestReadSchemaDirFromEmbeddings with your version x.x
Once you are done with these use the ./cadence-cassandra-tool to update the schema

Q: What's the format of manifest.json

Example below:

MinCompatibleVersion is the minimum schema version that your code can handle
SchemaUpdateCqlFiles are list of .cql files containg your create/alter commands

{
    "CurrVersion": "0.1",
    "MinCompatibleVersion": "0.1",
    "Description": "base version of schema",
    "SchemaUpdateCqlFiles": [
        "base.cql"
    ]
}