Planetscale Best Practices Matrix Agent Skill

Best-practices matrix

Purpose

Map database findings to recommended PlanetScale features. Use this to ensure the assessment does not miss major safety and operational surfaces.

Cross-engine recommendations

Query Insights

Recommend for every production database:

• Review slow, expensive, high-frequency, and erroring query patterns.
• For Postgres, sort Insights by CPU (sort=cpuTime on the Insights API)

when diagnosing CPU pressure.

• For sharded Vitess, review vindex usage per query pattern and the usage

trend after index or routing changes.

• Correlate regressions with deploys.
• Use tags/comments to map queries back to code.
• Use tag filtering/navigation in Query Insights: the tags API

(insights/tags, insights/tags/summaries) on both engines, plus

tag:key:value filtering and per-execution tag drill-down in the Vitess

dashboard.

• Use anomalies as alert and automation inputs.

Webhooks

Recommend for operational events:

• Anomalies.
• Storage pressure.
• Branch readiness/sleeping.
• Primary promotion.
• Maintenance.
• Schema recommendations where available.
• Deploy request lifecycle for Vitess.

MCP and agents

Recommend:

• Use insights-only MCP for most autonomous analysis.
• Use full MCP only with narrow scopes and read-only default.
• Put database targeting and safety rules in AGENTS.md.
• Agents generate PRs/issues/change plans; humans approve database changes.

SQLCommenter / query tags

Recommend:

• Add framework-native SQLCommenter-compatible instrumentation.
• Use low-cardinality tags.
• Include application, service, route/job, feature, source, and release SHA.
• Avoid PII and unbounded IDs.

Schema recommendation workflow

Recommend:

• Triage open recommendations.
• Correlate with code and Insights.
• Convert into migrations or branch changes.
• Test before production.
• Apply only through approved workflow.

Vitess-specific recommendations

Safe migrations

Recommend for production branches and staging branches that accept deploy requests.

Deploy requests

Recommend for schema changes into protected branches.

Force cutover discipline

Recommend documenting who may use "force cutover now" for deploy requests

delayed by long-running transactions. It stops running transactions to finish

schema cutover, so frequent use should trigger workload review before enabling

aggressive cutover as the database default.

Admin approval

Recommend for production deploy requests in multi-admin organizations.

In a single-admin organization, approval alone is not a guard against agents: that admin can

open and approve the same deploy request. Prefer a separate agent identity, or a service token

that cannot approve deploy requests.

Gated deployments

Recommend when cutover timing and human control matter.

Schema revert runbook

Recommend documenting revert responsibilities and the application rollback relationship.

Branch strategy

Recommend production, staging, and short-lived development branches with safe migrations on protected targets.

Sharding/keyspace review

Recommend when query patterns or growth suggest shard-awareness problems. Do not reshard automatically.

Postgres-specific recommendations

User-defined roles

Recommend for application servers instead of default role. If roles are managed

by Terraform and passwords should stay outside Terraform state, prefer

planetscale_postgres_redacted_branch_role plus a separate password reset and

secret-manager storage path.

pg_strict

Recommend for application roles after evaluation, especially to block accidental full-table update/delete mistakes.

Traffic Control

Recommend for resource isolation of agents, exports, reports, workers, integrations, BI, and known expensive fingerprints.

Backups and PITR

Recommend verifying retention and restore drill coverage.

If Terraform is the customer's source of truth, recommend managing backup

policies there so backup posture changes are reviewed as infrastructure code.

PgBouncer and connection pooling

Recommend where connection churn or serverless/edge behavior creates pressure, subject to transaction-pooling limitations.

Private connectivity and IP restrictions

Recommend for customers requiring private network posture or reduced public exposure. Treat changes as production-risking.

Extensions

Recommend only when use case is clear and restart/activation impact is accepted.

Include auto_explain when automatic plan logging for slow queries would

materially improve diagnosis and the resulting log volume is acceptable.

If Terraform manages Postgres branch parameters or supported extensions, keep

that source of truth aligned with approved dashboard/API changes.

Live connections

Recommend inspecting pscale branch connections top during active connection

pressure incidents to identify sessions, blockers, and idle-in-transaction

roots without relying on normal database connection capacity.

Output

For each matrix item, mark:

• Applies: yes/no/unknown.
• Current state.
• Gap.
• Value: the specific measured finding this feature addresses (query

fingerprint, anomaly count, incident, metric). State the mechanism and

the measurement. Gaps are capability gaps with quantified impact, not

risks safely avoided.

• Recommendation ID.
• Approval requirement.

End with:

“No changes have been applied.”