Handling requests for data stored in database tables
View Patent ↗Method for handling requests for data stored in database tables is provided. The method includes receiving a request for data stored in a database table, the database table including non-hash and hash columns, a hash column including hash values computed based on non-hash values in at least one non-hash column, generating database queries that are executable to retrieve data stored in the database table satisfying the request, each database query using a different combination of columns in the database table, ranking the database queries based on desirability, determining whether any of the database queries only uses indexed columns, responsive to one or more of the database queries only using indexed columns, selecting a highest ranked of the one or more database queries that only uses indexed columns for execution.
1. A method for handling requests for data stored in database tables, the method comprising:
receiving a request for data stored in a database table, the database table including non-hash and hash columns, a hash column including hash values computed based on non-hash values in at least one non-hash column;
generating a plurality of database queries that are executable to retrieve data stored in the database table satisfying the request, each database query using a different combination of columns in the database table, wherein each database query has already been optimized by a database management system through selection of an execution plan;
ranking database queries based on desirability, a database query using a higher number of hash columns being more desirable than a database query using a lower number of hash columns;
analyzing the database queries to determine whether any of the database queries only uses indexed columns of the database table; and
responsive to one or more of the database queries only using indexed columns of the database table, selecting a highest ranked of the one or more database queries for execution.
2. The method of claim 1 , wherein responsive to none of the database queries only using indexed columns, the method further comprises:
executing a highest ranked of the database queries.
3. The method of claim 1 , wherein responsive to none of the database queries only using indexed columns, the method further comprises:
outputting an error message.
4. The method of claim 1 , further comprising:
returning data retrieved from execution of the selected database query.
5. The method of claim 1 , wherein the plurality of queries is analyzed in ranking order.
6. A computer-readable medium containing program instructions for handling requests for data stored in database tables, wherein execution of program instructions by one or more processors of a computer system causes the one or more processors to carry out the steps of:
receiving a request for data stored in a database table, the database table including non-hash and hash columns, a hash column including hash values computed based on non-hash values in at least one non-hash column;
generating a plurality of database queries that are executable to retrieve data stored in the database table satisfying the request, each database query using a different combination of columns in the database table, wherein each database query has already been optimized by a database management system through selection of an execution plan;
ranking database queries based on desirability, a database query using a higher number of hash columns being more desirable than a database query using a lower number of hash columns;
analyzing the database queries to determine whether any of the database queries only uses indexed columns of the database table; and
responsive to one or more of the database queries only using indexed columns of the database table, selecting a highest ranked of the one or more database queries for execution.