User-Optimizer Communication using Abstract Plans in Sybase ASE

imizer Communication using Abstract Plans in Sybase ASE Query optimizers are error prone, due to both their nature and the increased search space that modern query processing requires them to manage. This paper introduces the Sybase Server Enterprise (ASE) Abstract Plan (AP) language, a novel technology that puts together a set of proven techniques to palliate optimizer mistaken decisions. The AP language is a 2-way user-optimizer communication mechanism based on a physical level relational algebra. AP expressions are used both by the optimizer to describe the plan that it selected and by the user to direct the optimizer choices. APs are not textually part of the query. They are persistent objects stored in the system catalogs. APs yield important performance gains by eliminating all optimizer errors.

• Type: Conference
• Year: 2001
• Where: VLDB
• Authors: Mihnea Andrei, Patrick Valduriez
• Keywords: Abstract Plan, Optimizer Mistaken Decisions, Sybase ASE Query, VLDB 2001