Block non-logged operations

You can improve the integrity of your HADR configuration during failover operations by activating the blocknonlogged database configuration parameter.

Using the blocknonlogged database configuration parameter

For HADR databases, set the blocknonlogged database configuration parameter to YES to prevent operations that are not fully logged. Such operations include:
  • CREATE TABLE and ALTER TABLE statement with NOT LOGGED INITIALLY option
  • CREATE TABLE and ALTER TABLE statement with NOT LOGGED parameter for a LOB column
  • LOAD command with NONRECOVERABLE option
  • LOAD command with COPY NO option

These non-logged operations cause the table on standby to not be maintained. When the standby becomes a new primary after failover, either access to the table is not possible or, in the case of the NOT LOGGED LOB column, the data is binary 0. Because of the potential impact on applications, you need to prevent these operations by configuring the blocknonlogged database configuration parameter.