oracle transaction isolation level

Posted on 2009-06-23 filed under: Oracle (RSS) 20 views

oracle 11g provides three types of transaction isolation level

1. Reading to submit:

The default transaction isolation level. Services to see the implementation of each query in the query data before the start. oracle never read dirty data.

set transaction isolation level read committed;

2. Serialization

Serial affairs of affairs can only be seen to be submitted before the start of changes to office to do.

set transaction isolation level seralizable;

3. Read-only

Services can only be read-only to see the services to be submitted before the start of changes.

set transaction isolation level read only;

Set transaction statements in order to retain the network and processing costs (that is, do not need to start the conversation), alter session statement can be used to establish isolation layer

alter session set isolation_level serializable;

alter session set isolation_level read committed;

Line which is serializable lock layer, at the same time to avoid duplication of time, the phenomenon of the shadow of time.