Release 10.1A: OpenEdge Data Management:
SQL Development

Inspecting what the optimizer produces

The OpenEdge SQL Engine provides the capability to examine the query trees produced by the optimizer, which it has used to actually execute a query. The engine’s internal cache of recent query plans is available as a series of text columns in a virtual system table called _Sql_Qplan. Note that like all other virtual system tables, the data in this table do not actually exist as a table. The table rows are constructed on demand from data structures in the server’s memory.