DEALLOCATE

Enterprise command reference.

Command Snapshot

Field	Value
Category	Session and Transaction Control
Mutates Data	Yes/Depends
Scope	Statement
Privilege Model	Session-scoped variants require session rights; global variants require administrative privilege.

Purpose

Executes the DEALLOCATE SQL command with MonkDB distributed runtime semantics.

Syntax

DEALLOCATE [PREPARE] { name | ALL }

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 control session behavior, cursors, or transaction compatibility settings.
Use when client compatibility or session-scoped runtime behavior must be explicit.

When Not to Use

Avoid relying on PostgreSQL-compatible clauses whose behavior is intentionally no-op in MonkDB.

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

SQL Statement

DEALLOCATE [PREPARE] { name | ALL }

Description

The DEALLOCATE command serves to release resources linked to a previously prepared SQL statement. While prepared statements are automatically deallocated at the conclusion of a session, this command provides a means for explicit deallocation. It is frequently utilized by clients, such as libpq, as an alternative to the protocol's Close (F) message.

Key Points:

Automatic Deallocation: Prepared statements are automatically deallocated at the end of a session.
Explicit Deallocation: Use the DEALLOCATE command to manually free resources associated with a specific prepared statement or all prepared statements.

Parameters

name: Specifies the identifier of the prepared statement that is to be deallocated.
ALL: Removes all prepared statements associated with the current session.

Examples

Example 1: Deallocate a Specific Prepared Statement

DEALLOCATE emp_info;

This command explicitly deallocates the prepared statement named emp_info.

Example 2: Deallocate All Prepared Statements

DEALLOCATE ALL;

This command frees resources for all prepared statements in the current session.

Verification

To confirm that a prepared statement has been deallocated:

SELECT name, statement FROM pg_prepared_statements;

After executing DEALLOCATE, the specified statement will no longer appear in this view.

Notes

The PREPARE keyword in the syntax is optional and ignored.
The SQL standard includes a DEALLOCATE statement, but it is primarily used in embedded SQL contexts.