isolation_level option

0, 1, 2, 3, Snapshot, Statement-snapshot, Readonly-statement-snapshot

0

A temporary setting for the current user is established by the JDBC driver (0).

A temporary setting for the current user is established by SAP Open Client and jConnect TDS connections (1).

This option controls the locking isolation level as follows:

• 0

  Allow dirty reads, non-repeatable reads, and phantom rows.

• 1

  Prevent dirty reads. Allow non-repeatable reads and phantom rows.

• 2

  Prevent dirty reads and non-repeatable reads. Allow phantom rows.

• 3

  Serializable. Prevent dirty reads, non-repeatable reads, and phantom rows.

• Snapshot

  Use a snapshot of committed data from the time when the first row is read or updated by the transaction.

• Statement-snapshot

  For each statement, use a snapshot of committed data from the time when the first row is read from the database. Non-repeatable reads and phantom rows can occur within a transaction, but not within a single statement.

• Readonly-statement-snapshot

  For read-only statements, use a snapshot of committed data from the time when the first row is read from the database. Non-repeatable reads and phantom rows can occur within a transaction, but not within a single statement. For updatable statements, use the isolation level specified by the updatable_statement_isolation option (can be one of 0 (the default), 1, 2, or 3).

Set the allow_snapshot_isolation option to On to use the Snapshot, Statement-snapshot, or Readonly-statement-snapshot settings.

Queries running at isolation level Snapshot, Statement-snapshot, or Readonly-statement-snapshot see a snapshot of a committed state of the database.

You can override any temporary or PUBLIC settings for this option within individual INSERT, UPDATE, DELETE, SELECT, UNION, EXCEPT, and INTERSECT statements by including an OPTION clause in the statement.