Setting Up Send and Receive Queue Spool Areas

The term data queue refers to both the send queue and the receive queue. Enterprise Replication collects information from the logical logs and places the data to be transferred in the send queue. Then Enterprise Replication transfers the contents of the send queue to the receive queue on the target server. Enterprise Replication on the target reads the data from the receive queue and applies the changes to the tables on the target server.

The send and receive queues reside in memory and are managed by the Reliable Queue Manager (RQM). The CDR_QUEUEMEM configuration parameter (CDR_QUEUEMEM Configuration Parameter) specifies the amount of memory space that is available for the data queues.

When a queue in memory fills (for the receive queue, this only occurs with large transactions), the transaction buffers are written (spooled) to disk. Spooled transactions consist of transaction records (headers that contain internal information for Enterprise Replication), replicate information (summaries of the replication information for each transaction), and row data (the actual replicated data). Spooled transaction records and replication records are stored in transaction tables and replication tables in a single dbspace. Spooled row data is stored in one or more sbspaces.
Important: To prevent the send and receive queues from spooling to disk, see Preventing Memory Queues from Overflowing.