Besides <command>SELECT</command> queries, the commands can include data
modification queries (<command>INSERT</command>,
<command>UPDATE</command>, and <command>DELETE</command>), as well as
- other SQL commands. (The only exception is that you cannot put
- <command>BEGIN</>, <command>COMMIT</>, <command>ROLLBACK</>, or
- <command>SAVEPOINT</> commands into a <acronym>SQL</acronym> function.)
+ other SQL commands. (You cannot put transaction commands, e.g.
+ <command>COMMIT</>, <command>SAVEPOINT</>, and some utility
+ commands, e.g. <literal>VACUUM</>, into an <acronym>SQL</acronym> function.)
However, the final command
must be a <command>SELECT</command> or have a <literal>RETURNING</>
clause that returns whatever is