Abstract: A database system configured to optimize query execution through an opportunistic scheduling approach. The database system generates a query plan and identifies a contingent database operation within the query plan, the contingent database operation being dependent on a completion of at least one additional operation. The database system schedules the contingent operation using an opportunistic scheduler. The database system executes the query plan comprising processing the contingent database operation after the completion of the at least one additional operation.

Abstract: Methods, systems, and computer programs are presented for scheduling and executing request plans using an opportunistic approach. An opportunistic scheduler generates a request plan for a request on a cloud data platform, the request plan comprising a plurality of operations and identifies a plurality of contingent operations from the plurality of operations of the request plan. The opportunistic scheduler schedules the plurality of contingent operations for execution and sets the scheduled plurality of contingent operations to execute at a specific position in the request plan. The opportunistic scheduler sets remaining operations for execution by any available thread as threads that are processing the request plan become available and processes the request plan according to the scheduled plurality of contingent operations.

Abstract: Methods, systems, and computer programs are presented for scheduling and executing request plans using an opportunistic approach. An opportunistic scheduler generates a request plan for a request on a cloud data platform, the request plan comprising a plurality of operations and identifies a plurality of contingent operations from the plurality of operations of the request plan. The opportunistic scheduler schedules the plurality of contingent operations for execution and sets the scheduled plurality of contingent operations to execute at a specific position in the request plan. The opportunistic scheduler sets remaining operations for execution by any available thread as threads that are processing the request plan become available and processes the request plan according to the scheduled plurality of contingent operations.

Abstract: A database scheduler system can be implemented on a distributed database system. The system schedules operations in a lightweight approach that reduces idling and increases parallel processing of database operations for a query on data of the database. The system performs restarts of individual operators or fragments of a query without restarting the entire query.