Disk Store Persistence Attributes

SQLFire persists data on disk stores in synchronous or asynchronous mode.

You configure the persistence mode for a table in the CREATE TABLE statement, while attributes to control asynchronous persistence are configured in the CREATE DISKSTOREstatement.

In synchronous mode, SQLFire writes each DML operation to the OS buffer as part of the statement execution. This mode provides greater reliability than asynchronous mode, but with lower performance.

In asynchronous mode, SQLFire batches DML statements before flushing them to the OS buffers. This is faster than synchronous mode, but batch operations may be lost if a failure occurs. (You can use redundancy to ensure that updates are successfully logged on another machine.) In asynchronous mode, you can control the frequency of flushing batches by setting the following attributes when you create a named disk store:


Note: Always start all SQLFire servers and peer processes that host data on disk in parallel. A SQLFire process with persistent data may wait for other processes to startup first to guarantee consistency.

Always use the shutdown-all command to gracefully shut down a cluster. This allows each member to reach a consistent replication state and record that state with other replicas in the cluster. When you restart peers after a graceful shutdown, each member can recover in parallel without waiting for others to provide consistent replication data.