# pg_ltree_query Query hierarchical relationships in ltree columns. Supports exact paths (descendants/ancestors) and lquery patterns with wildcards. Agent View of the PolicyLayer registry record for `pg_ltree_query`. HTML page: https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-ltree-query ## Facts - Tool: `pg_ltree_query` - Server: PostgreSQL MCP Server (`@neverinfamous/postgres-mcp`) — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp.md - Install: `npx -y @neverinfamous/postgres-mcp` - Homepage: https://github.com/neverinfamous/postgresql-mcp.git - Risk category: Read (Low risk) - Registry record: grade F, identity unverified - Server rate-limited: no - Parameters: 0 - Recommended policy verdict: Allowed ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "pg_ltree_query", "arguments": {} } } ``` ## Why pg_ltree_query is rated Low The tool is explicitly a query function that searches for and retrieves hierarchical data using path and pattern matching. No write, delete, execute, or financial operations are described. The 'Query' in the name and 'Query hierarchical relationships' in the description confirm this is a retrieval-only operation with no side effects. From the tool's own definition: "Tool description states 'Query hierarchical relationships' and 'Supports exact paths (descendants/ancestors) and lquery patterns' — these are read operations that retrieve data matching hierarchical patterns in ltree columns without modifying state." ## Use case AI agents call pg_ltree_query to retrieve information from PostgreSQL MCP Server without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere. ## Recommended policy (PolicyLayer) Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches PostgreSQL MCP Server: ```json { "version": "1", "default": "deny", "tools": { "pg_ltree_query": {} } } ``` ## Other tools on PostgreSQL MCP Server (273) - `pg_cascade_simulator` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cascade-simulator.md - `pg_cron_cleanup_history` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cron-cleanup-history.md - `pg_cron_unschedule` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cron-unschedule.md - `pg_detach_partition` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-detach-partition.md - `pg_doc_drop_collection` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-doc-drop-collection.md - `pg_doc_remove` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-doc-remove.md - `pg_drop_index` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-drop-index.md - `pg_drop_schema` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-drop-schema.md - `pg_drop_sequence` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-drop-sequence.md - `pg_drop_table` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-drop-table.md - `pg_drop_view` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-drop-view.md - `pg_kcache_reset` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-kcache-reset.md - `pg_migration_rollback` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-migration-rollback.md - `pg_partman_set_retention` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-partman-set-retention.md - `pg_reset_stats` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-reset-stats.md - `pg_role_drop` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-role-drop.md - `pg_text_normalize` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-text-normalize.md - `pg_truncate` — Destructive — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-truncate.md - `pg_analyze` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-analyze.md - `pg_analyze_query_indexes` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-analyze-query-indexes.md - `pg_buffer` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-buffer.md - `pg_cancel_backend` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cancel-backend.md - `pg_cluster` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cluster.md - `pg_cron_create_extension` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cron-create-extension.md - `pg_cron_schedule` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cron-schedule.md - `pg_cron_schedule_in_database` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-cron-schedule-in-database.md - `pg_explain_analyze` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-explain-analyze.md - `pg_geo_cluster` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-geo-cluster.md - `pg_geo_transform` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-geo-transform.md - `pg_geometry_transform` — Execute — https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-geometry-transform.md - …and 243 more: https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-neverinfamous-postgres-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-neverinfamous-postgres-mcp