Generate and apply YDB table schema DDL safely

Safe schema workflow

• Inspect the target tenant with local_ydb_status_report and local_ydb_scheme.
• Call local_ydb_generate_schema with a strict JSON table spec and validate: true.
• Review generated DDL, script SHA-256, warnings, risk, and SDK validation status.
• Call local_ydb_apply_schema with action: validate.
• Call local_ydb_apply_schema with action: apply and confirm: false to return the plan.
• Execute only after approval with the exact same apply call plus confirm: true.
• Verify with local_ydb_scheme using action: describe.

Example generator spec

{
  "validate": true,
  "statements": [
    {
      "kind": "createTable",
      "tableName": "schema_apply_smoke",
      "columns": [
        { "name": "id", "type": "Uint64", "notNull": true },
        { "name": "value", "type": "Utf8" }
      ],
      "primaryKey": ["id"],
      "indexes": [
        {
          "name": "schema_apply_smoke_by_value",
          "columns": ["value"],
          "global": true
        }
      ]
    }
  ]
}

Important constraints

• Use notNull only for primary key columns in generated CREATE TABLE specs.
• Use the top-level store field instead of with.STORE.
• Keep secondary and vector indexes on row-oriented tables.
• Do not add an index on a column added or dropped in the same ALTER TABLE spec.
• Prefer adding vector indexes after representative data is loaded.