Abstract plans were introduced in Adaptive Server release 12.0 as a means for System Administrators and performance tuners to protect the overall performance of a server from changes to query plans, such as:
Adaptive Server software upgrades that affect optimizer choices
New Adaptive Server features that change query plans
Changing tuning options such as the parallel degree, table partitioning, or indexing
Adaptive Server can capture query text and save an abstract plan for a query in a system table called sysqueryplans. Using a rapid hashing method, incoming SQL queries can be compared to stored query text, and if a match is found, the saved abstract plan is used to execute the query.
For more information on abstract query plans, see the Performance and Tuning Guide: Optimizer and Abstract Plans.
For a quick overview of how to use abstract query plans to troubleshoot performance problems after an upgrade, see the TechNote “Using and Maintaining Abstract Query Plans” at http://my.sybase.com.
