spanner-provisioning

# Spanner Instance Provisioning Guidelines <!-- Disabling markdownlint MD029 to provide explicit ordering to avoid confusing the LLM. --> <!-- markdownlint-disable MD029 --> Use this skill when provisioning, configuring, or updating a Cloud Spanner instance in this repository. ## 1. Edition Selection Rules Spanner features are associated with specific database editions. To optimize costs while ensuring functionality: - **ENTERPRISE Edition**: Must be selected if the database schema utilizes features such as: - **Spanner Graph**: Identified by the presence of `CREATE PROPERTY GRAPH` in the DDL. - **Vector Search Index**: Identified by the presence of `CREATE VECTOR INDEX` in the DDL. - **STANDARD Edition**: Should be selected for basic relational workloads that do not use graph traversal or vector search. ## 2. Compute Capacity Rules Compute capacity (processing units) must be chosen based on the environment's purpose: - **Development & Testing (`dev` / `test`)**: - Enforce the minimum compute capacity of **100 processing units** to minimize cloud expenditures. - **Production (`prod`)**: - Minimum compute capacity should start at **1000 processing units** (equivalent to 1 node) or higher as required by workload demands, unless autoscaling is configured. ## 3. Idempotency and Schema Application When applying DDL schemas to an existing Spanner database: - **Avoid Duplication Errors**: Standard Spanner DDL statements (like `CREATE TABLE`, `CREATE PROPERTY GRAPH`, or `CREATE VECTOR INDEX`) will return errors if the object already exists. - **Verification Check**: Before applying the full DDL schema, verify if key objects (e.g., node tables) already exist in the database. - You can query `INFORMATION_SCHEMA.TABLES` (e.g., checking if the primary table name is present) to determine if the schema has been initialized. - If the database schema is already initialized, skip executing duplicate creation DDL statements. - **Schema Updates**: For incremental updates, use compatible statements (such as `ALTER TABLE`) rather than running the full creation script. - **Recreation**: If a complete schema reset is required, drop and recreate the database before applying the full schema.