Enterprise Replication Queues

One group of sysmaster tables shows information about Enterprise Replication queues. The sysmaster database reports the status of these queues in the tables that have the suffixes _buf and _txn.

The name of each table that describes an Enterprise Replication queue is composed of the following three pieces:

• syscdr, which indicates that the table describes Enterprise Replication
• An abbreviation that indicates which queue the table describes
• A suffix, either _buf or _txn, which specifies whether the table includes buffers or transactions

Selecting from these tables provides information about the contents of each queue. For example, the following SELECT statement returns a list of all transactions queued on the send queue:

SELECT * FROM syscdrsend_txn

The following example returns a list of all transactions queued on the in-memory send queue and returns the number of buffers and the size of each buffer for each transaction on the send queue:

SELECT cbkeyserverid,cbkeyid,cbkeypos,count(*),sum(cbsize)
   from syscdrsend_buf 
   group by cbkeyserverid, cbkeyid, cbkeypos
   order by cbkeyserverid, cbkeyid, cbkeypos

All queues are present on all the replication servers, regardless of whether the replication server is a source or a target for a particular transaction. Some of the queues are always empty. For instance, the send queue on a target-only server is always empty.

Each queue is two-dimensional. Every queue has a list of transaction headers. Each transaction header in turn has a list of buffers that belong to that transaction.