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PROGRESS Driver Configuration Advanced Tab

Default Isolation Level

Here you can specify the default isolation level for the concurrent transactions.

READ COMMITTED

A share lock is acquired on the record that is read. The duration of the lock varies. The uncommitted modified records can't be read. However, if a record is read multiple times in the same transaction, the state of the record can be different each time.

READ UNCOMMITTED

Allows dirty reads, nonrepeatable reads, and phantoms. When a record is read, no record locks are aquired. This forces read-only use. Allows a user application to read records that were modified by other applications but have not yet been committed.

NOTE: It is recommended to set READ UNCOMMITED to avoid "Lock Table is Full" error. 

REPEATABLE READ

Allows phantoms and prohibits dirty reads and nonrepeatable reads. Each time a record is read, a share lock is acquired on that record and held until the end of the current transaction. The uncommitted modified records can't be read. If a record is read multiple times in the same transaction, the state of the record remains the same. This is the default isolation level.

SERIALIZABLE

Dirty reads, nonrepeatable reads, and phantoms are prohibited. The SELECT statement executed more than once within one transaction returns the same set of rows every time. Concurrent transactions will not affect each other and behave as if they were executing serially, not concurrently. If the table is accessed with this isolation level setting, the whole table is locked. The table lock is held until the end of the current transaction.

Fetch Array Size

Specifies the number of rows fetched by the driver from the server. The default is 50 rows.

sqlways/users-guide/setting-up-database-connection/progress/driver/advanced-tab.txt · Last modified: March 20, 2013, 04:15:39 AM (external edit)
 
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