set.transaction.readonly()

Syntax

long
         set.transaction.readonly()

Description

This defines a transaction as read only, with read consistency. The transaction can only read records (without locks) from the database; it cannot update the database. Read consistency is retained during the entire transaction. That is, your view of the database does not change even when the database is updated by other users.

When included, this function must be the first command of a transaction. So, you must include it either at the start of the program or immediately following a commit.transaction() or abort.transaction() call.

Because it is not possible to update the database in a read-only transaction, you can use only the following database calls in the transaction:

• db.first()
• db.lt()
• db.last()
• db.le()
• db.next()
• db.set.to.default()
• db.prev()
• db.change.order()
• db.gt()
• db.indexinfo()
• db.ge()
• db.nr.indices()
• db.eq()
• db.nr.rows()
• db.cur()
• db.row.length()
• db.bind()
• db.record.to.columns()
• db.unbind()
• db.columns.to.record()
• db.error()

Context

Bshell function.

Related topics

• Overview
• Synopsis