Static analysis of a SQL statement to determine the PostgreSQL lock level it will require, whether it forces a full table rewrite, and an estimated duration based on target table size. Returns warnings for ACCESS EXCLUSIVE locks on busy production tables and concrete recommendations (e.g., use CR...
AI agents call lock_check to retrieve information from Postgres without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs static analysis only: it inspects a SQL statement and returns metadata about lock levels, rewrite requirements, and duration estimates. It does not execute any SQL, modify any data, or trigger any database operations. It is purely a read/analysis tool that produces warnings and recommendations.
From the tool's definition 'Static analysis of a SQL statement to determine the PostgreSQL lock level it will require' and 'Use BEFORE running DDL on production' — the tool analyzes and returns information without executing anything
Attacks that exploit this kind of access
Static analysis of a SQL statement to determine the PostgreSQL lock level it will require, whether it forces a full table rewrite, and an estimated duration based on target table size. Returns warnings for ACCESS EXCLUSIVE locks on busy production tables and concrete recommendations (e.g., use CREATE INDEX CONCURRENTLY, NOT VALID + VALIDATE CONSTRAINT, etc). Use BEFORE running DDL on production. Knows lock semantics for ALTER TABLE variants, CREATE/DROP INDEX (concurrent vs not), VACUUM, CLUSTER, REFRESH MATERIALIZED VIEW, and more. It is categorised as a Read tool in the Postgres MCP Server, which means it retrieves data without modifying state.
Register the Postgres MCP server in PolicyLayer and add a rule for lock_check: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Postgres. Nothing to install.
lock_check is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the lock_check rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for lock_check. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
lock_check is provided by the Postgres MCP server (teja-sudo/postgres-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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