SQL syntax to cancel executing query, phase 2 This check-in causes queries to register with the cancel broker using a nowait Seabed message, and to process the completion of the message by canceling the executing query if the cancel broker so indicates in the message reply. The check-in includes new test cases in the regression test to cancel different types of SELECT queries.
These types of queries do not yet respond to cancel: 1. Queries that are decomposed into child queries, e.g., CREATE INDEX, CREATE TABLE AS, UPDATE STATISTICS, etc; 2. UPDATE and DELETE 3. INSERT queries might work now, but haven't been tested.
Changes to support OSS poc. This checkin contains multiple changes that were added to support OSS poc. These changes are enabled through a special cqd mode_special_4 and not yet externalized for general use. A separate spec contains details of these changes. These changes have been contributed and pre-reviewed by Suresh, Jim C, Ravisha, Mike H, Selva and Khaled. All dev regressions have been run and passed.