spanner-basics

SKILL.md

Spanner Basics

This skill provides core workflows and guidance for administering and developing with Google Cloud Spanner, a fully managed, mission-critical database service offering global transactional consistency and automatic, synchronous replication for high availability.

Core Principles

Performance First: Spanner scales horizontally. Efficiency is tied to
Primary Key design. Always warn against using monotonically increasing/decreasing
values (like sequential timestamps) as the first part of a primary key to avoid hotspots.

Schema Design: Prefer interleaved tables for strongly related parent-child data
that is frequently accessed together.

Safety

[!CAUTION] CRITICAL INSTRUCTION: You MUST obtain explicit user confirmation before making any non-emulator database changes (DML or DDL) or destructive operations (such as dropping tables, indexes, or any other Spanner resources). Do not execute them automatically; instead, output the command (e.g., gcloud spanner databases ddl update) and ask for explicit user approval.
When database access is unavailable or authentication fails, do not block on trying to verify the existence of the instance, database, or table. Assume the provided resources exist and directly generate the DDL commands.

Common Workflows