DROP FOREIGN TABLE
Enterprise command reference.
Command Snapshot
| Field | Value |
|---|---|
| Category | Federation (FDW) |
| Mutates Data | Yes/Depends |
| Scope | Cluster / Object |
| Privilege Model | Requires administrative privilege on foreign server, table, and mapping objects. |
Purpose
Defines, changes, or removes schema and metadata objects.
Syntax
DROP FOREIGN TABLE [ IF EXISTS ] name [, ...]
Operational Notes
- Use schema-qualified identifiers in automation and automation pipelines.
- Validate behavior in staging for cluster-impacting or governance-impacting changes.
- Confirm runtime effects through system tables and metrics before and after execution.
When to Use
- Use to register and query external data systems through SQL federation.
- Use when centralized query execution is preferred over external engine orchestration.
When Not to Use
- Avoid expecting full pushdown for complex joins/aggregations unless explicitly supported.
Common Errors and Troubleshooting
| Symptom | Likely Cause | Action |
|---|---|---|
| Permission denied / unauthorized | Missing privilege on object or cluster scope | Re-run with required grants or elevated admin role. |
| Analysis/parse error | Syntax variant or object shape mismatch | Compare with canonical syntax and object definition. |
| Runtime failure under load | Resource limits, breaker pressure, or node state transitions | Check sys.jobs, sys.operations, sys.checks, and retry after mitigation. |
Cross-References
Detailed Reference
The DROP FOREIGN TABLE statement is a DDL (Data Definition Language) command used to remove a foreign table from a database. Here's an expanded overview of its syntax, description, parameters, and clauses, focusing on MonkDB and other relevant systems.
SQL Statement
DROP FOREIGN TABLE [ IF EXISTS ] name [, ...]
Description
DROP FOREIGN TABLE is used to delete a foreign table, which is a table that represents data from an external database accessed through a foreign data wrapper. Dropping a foreign table does not affect the actual data in the external database; it only removes the local reference to that data.
Parameters
- name: The
nameof the foreign table to be dropped. Multiple tables can be specified by separating them with commas.
Clauses
IF EXISTS
By default, DROP FOREIGN TABLE raises an error if the specified table does not exist. The IF EXISTS clause prevents this error and instead issues a notice if the table does not exist.
Permissions
In MonkDB, dropping a foreign table requires AL (Admin Level) permission on the table, schema, or cluster level. In other systems like PostgreSQL and Greenplum, only the owner of the foreign table can remove it.
Examples
Example 1. Dropping a Single Foreign Table
DROP FOREIGN TABLE my_foreign_table;
Example 2. Dropping Multiple Foreign Tables
DROP FOREIGN TABLE my_foreign_table1, my_foreign_table2;
Example 3. Using IF EXISTS to Avoid Errors
DROP FOREIGN TABLE IF EXISTS my_foreign_table;