BEGIN

Enterprise command reference.

Command Snapshot

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

Purpose

Executes the BEGIN SQL command with MonkDB distributed runtime semantics.

Syntax

BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ]

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

The BEGIN statement in MonkDB is recognized for compatibility with PostgreSQL clients but does not initiate actual transactions, as MonkDB does not support transactional operations.

SQL Statement

BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ]

Where transaction_mode can include:

ISOLATION LEVEL isolation_level
READ WRITE or READ ONLY
[NOT] DEFERRABLE

And isolation_level options are:

SERIALIZABLE
REPEATABLE READ
READ COMMITTED
READ UNCOMMITTED

Description

Purpose: In MonkDB, the BEGIN statement does not initiate a transaction. Its primary function is to define a scope for declaring cursors without the HOLD option.
Behavior:
Cursors declared without HOLD are automatically closed upon execution of an END or COMMIT command.
Nested BEGIN statements are not supported; each BEGIN starts a new scope, regardless of previous BEGIN executions.

Parameters

WORK | TRANSACTION: Optional keywords included for compatibility; they have no operational effect in MonkDB.
transaction_mode: Specifies transaction characteristics such as isolation level and access mode. These parameters are accepted for syntax compatibility but do not influence behavior in MonkDB.

Notes

Transaction Support: MonkDB does not support traditional transactions. Statements like BEGIN, START TRANSACTION, COMMIT, and ROLLBACK are accepted for compatibility purposes but do not alter database behavior.
Cursor Management: While transactions are not supported, BEGIN can be used to establish a scope for cursors without the HOLD option, which are closed automatically upon END or COMMIT.

Permissions

Execution Rights: Any user with the ability to execute SQL statements can issue the BEGIN command. No special permissions are required.

Summary

Command	Description	Transaction Support	Cursor Scope Management
`BEGIN`	Starts a scope for cursors without `HOLD`; does not initiate a transaction.	No	Yes

While MonkDB does not support transactions, understanding the role of the BEGIN statement can aid in managing cursor scopes effectively within the database environment.