## 45.10. Transaction Management

In a procedure called from the top level or an anonymous code block (`DO` command) called from the top level it is possible to control transactions. To commit the current transaction, call the `commit` command. To roll back the current transaction, call the `rollback` command. (Note that it is not possible to run the SQL commands `COMMIT` or `ROLLBACK` via `spi_exec` or similar. It has to be done using these functions.) After a transaction is ended, a new transaction is automatically started, so there is no separate command for that.

Here is an example:

    CREATE PROCEDURE transaction_test1()
    LANGUAGE pltcl
    AS $$
    for {set i 0} {$i < 10} {incr i} {
        spi_exec "INSERT INTO test1 (a) VALUES ($i)"
        if {$i % 2 == 0} {
            commit
        } else {
            rollback
        }
    }
    $$;

    CALL transaction_test1();

Transactions cannot be ended when an explicit subtransaction is active.