spanner-provisioning

name	spanner-provisioning
description	Guidelines and rules for provisioning Google Cloud Spanner instances, including selecting the correct edition (Enterprise vs Standard) and compute capacity based on schema features (e.g., graphs and vector search) and environment purpose.

Spanner Instance Provisioning Guidelines

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.