Method and system for improving response time for database query execution
View Patent ↗Aspects for improving response time for database query execution are described. The aspects include comparing an estimate of sort pages needed for a database query against at least one threshold. A determination of whether to perform a parallel sort for the database query based on the comparison occurs, wherein response time improvement by the parallel sort is balanced against resource overhead of the parallel sort.
1. A method for improving response time for database query execution, the method comprising:
comparing a first estimate of a total data size of all sort pages needed for a database query against a first pre-determined data size; and
determining whether to perform a parallel sort for the database query based on the comparison, wherein response time improvement by the parallel sort is balanced against resource overhead of the parallel sort;
performing the parallel sort responsive to the first estimate exceeding the first pre-determined data size to reduce a response time for execution of the database query; and
displaying a result of the execution of the database query to a database user.
2. The method of claim 1 , wherein comparing further comprises comparing one or more second estimates corresponding to an estimated data size of a respective sort page against a second predetermined data size when the first estimate exceeds the first pre-determined data size.
3. The method of claim 2 , wherein determining whether to perform a parallel sort further comprises performing the parallel sort when one or more of the second estimates exceeds the second pre-determined data size.
4. A system for improving response time for database query execution, the system comprising:
a data processing system capable of parallel execution of database queries; and
a relational database management system operating on the data processing system, the database management system operable to compare a first estimate of a total data size of all sort pages needed for a database query against a first pre-determined data size, and determine whether to perform a parallel sort for the database query based on the comparison, wherein response time improvement by the parallel sort is balanced against resource overhead of the parallel sort;
performing the parallel sort responsive to the first estimate exceeding the first pre-determined data size to reduce a response time for execution of the database query; and
a display monitor to display a result of the execution of the database query to a database user.
5. The system of claim 4 , wherein the database management system further compares one or more second estimates corresponding to a data size of a respective sort page against a second predetermined data size when the first estimate exceeds the first pre-determined data size.
6. The system of claim 5 , wherein the database management system further performs the parallel sort when one or more of the second estimates exceeds the second we-determined data size.
7. A computer readable medium containing program instructions for improving response time for database query execution, the program instructions comprising:
comparing a first estimate of a total data size of all sort pages needed for a database query against a first pre-determined data size; and
determining whether to perform a parallel sort for the database query based on the comparison, wherein response time improvement by the parallel sort is balanced against resource overhead of the parallel sort;
performing the parallel sort responsive to the first estimate exceeding the first pre-determined data size to reduce a response time for execution of the database query; and
display a result of the execution of the database query to a database user.
8. The computer readable medium of claim 7 , wherein comparing further comprises comparing one or more second estimates corresponding to an estimated data size of a respective sort page against a second predetermined data size when the first estimate exceeds the first pre-determined data size.
9. The computer readable medium of claim 8 , wherein determining whether to perform a parallel sort further comprises performing the parallel sort when one or more of the second estimates exceeds the second pre-determined data size.
10. A computer-implemented method for performing parallel execution of a task in a database system, the method comprising:
receiving a task to be executed for a database query in the database system;
comparing a first estimate of a total data size of all parallel sub-tasks needed to execute the task against a first pre-determined data size;
comparing one or more second estimates corresponding to an estimated data size of a respective parallel sub-task against a second pre-determined data size, the second pre-determined data size being smaller than the first pre-determined data size;
if the first estimate exceeds the first pre-determined data size and if one or more of the second estimates exceeds the second pre-determined data size then,
generating a plurality of sub-tasks for satisfying the database query based on the received task; and
executing the generated sub-tasks in parallel within the database system;
display a result of the execution of the database query to a database user.
11. The method of claim 10 , wherein the received task comprises a sort.
12. The method of claim 10 , wherein the first pre-determined data size is (2) megabytes and the second pre-determined data size is (100) kilobytes.