Configuration and Tuning for Higher Performance

Depending upon your server resources, you can configure sybmigrate and the SAP ASE server for optimal performance.

Copy threads and create index threads are used to migrate tables and re-create indexes. When you are configuring sybmigrate during setup mode, the values of COPY_THREADS and INDEX_THREADS can increase the speed at which sybmigrate copies and migrates data.

The number of copy threads controls the number of tables for which data migration is done simultaneously. One copy thread is assigned to each table. When the thread has successfully completed one task, it moves on to another. Depending upon the size of your database and the resources for your SAP ASE server, you can increase the number of copy threads used during the migration process to improve performance.

Note: When you are migrating a large number of objects in parallel, check the value of SYBMIGRATE_MEMORY to verify that there is sufficient memory allocated to sybmigrate.

Index threads control the number of threads used to re-create indexes on the target SAP ASE tables. One thread per table is used to re-create the indexes. Once the indexes have been re-created on a table, the thread proceeds to the next successfully migrated table. Any threads without a task exits. The number of create index threads is expected to be substantially smaller than the number of copy threads.

If you configure INDEX_THREADS to a large number, be sure that the target SAP ASE server is also configured with a large number of sort buffers. The use of index threads takes up space in the target database, so make sure that the target database is configured with adequate space for the designated number of index threads. Also, you must configure the target database with extra space if you are going to be re-creating clustered indexes.