# pg_ltree_lca

Find the longest common ancestor of multiple ltree paths.

Agent View of the PolicyLayer registry record for `pg_ltree_lca`. HTML page: https://policylayer.com/tools/io-github-neverinfamous-postgres-mcp/pg-ltree-lca

## Facts

- Tool: `pg_ltree_lca`
- 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_lca",
    "arguments": {}
  }
}
```

## Why pg_ltree_lca is rated Low

This tool performs a computational query on ltree (PostgreSQL's hierarchical tree data type) to find common ancestor nodes. It has no side effects—it does not create, modify, delete, or execute arbitrary operations. It purely retrieves or derives information from existing data, fitting the Read category. Severity is low because misuse cannot cause data loss, financial harm, or unintended system modifications.

From the tool's own definition: "Tool name 'pg_ltree_lca' and description 'Find the longest common ancestor of multiple ltree paths' indicates a query operation that retrieves/computes information about existing hierarchical data without modifying it."

## Use case

AI agents call pg_ltree_lca 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_lca": {}
  }
}
```

## 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
