Replication Intrusions and Impacts on Sybase IQ

The only significant intrusions or impacts to the Sybase IQ replicate database are the system tables created in the Sybase IQ replicate database through the connection profile, and temporary tables created in the Sybase IQ replicate database to accommodate RTL bulk apply.

System Tables

The connection profile creates three tables in the Sybase IQ replicate database:

  • rs_threads – used by Replication Server to detect deadlocks and to perform transaction serialization between parallel DSI threads. An entry is updated in this table each time a transaction is started and more than one DSI thread is defined for a connection.

  • rs_lastcommit – contains information about replicated transactions applied to the replicate database. Each row in the rs_lastcommit table identifies the most recent committed transaction that was distributed to the replicate database from a primary database. Replication Server uses this information to ensure that all transactions are distributed.

    The Replication Server rs_get_lastcommit function retrieves information about the most recent transaction committed in the replicate database. For non-ASE replicate databases, the rs_get_lastcommit function is replaced in the database-specific function-string class by the query required to access the rs_lastcommit table in the replicate database.

  • rs_ticket_history – contains the execution results of Replication Server command rs_ticket. You can isssue the rs_ticket command for the primary database to measure the amount of time it takes for a command to move from the primary database to the replicate database. You can use this information to monitor Replication Server performance, module heartbeat, replication health, and table-level quiesce. The results of each execution of rs_ticket is stored in a single row of the rs_ticket_history table in the replicate database. You can query each row of the rs_ticket_history table to obtain results of individual rs_ticket executions, or to compare the results from different rows. Manually truncate the data in rs_ticket_history table if necessary.

Worktables

RTL creates temporary worktables inside the IQ temporary store of the Sybase IQ database to support RTL bulk apply.The worktables are created and dropped dynamically.

The amount of space required for the temporary tables in Sybase IQ depends on the amount of the data you expect to replicate to Sybase IQ. To adjust the Sybase IQ temporary database space to accommodate the temporary worktables, use the Sybase IQ alter dbspace command. See the Sybase IQ documentation for your version for more information. For example in Sybase IQ 15.0 and later:
ALTER DBSPACE dbspace-name ADD FILE FileHist3
‘/History1/data/file3’ SIZE 500MB