Limiting scans of loosely ordered and/or grouped relations in a database

A system for accessing data within a database object based on a query with a predicate including a plurality of conditional expressions, wherein an element of the database object is stored among a plurality of different storage regions with each storage region being associated with first and second range values indicating a value range for element values within that storage region, the system comprising:

• at least one processor configured to:
• apply each conditional expression of the query predicate to at least one of the first and second range values for each of the storage regions to produce evaluation results of that conditional expression for the storage regions;
• combine the evaluation result of each conditional expression for a corresponding storage region to produce aggregated results for each of the storage regions, wherein the aggregated result for a corresponding storage region indicates at least one of satisfaction of the conditional expressions for that storage region, failure to satisfy the conditional expressions for that storage region, and insufficient information to evaluate the conditional expressions for that storage region;
• provide information to evaluate one or more conditional expressions for a storage region in response to the aggregated result for that storage region indicating insufficient information;
• and
• scan one or more corresponding individual storage regions based on the aggregated results for those storage regions.

A computer program product for accessing data within a database object based on a query with a predicate including a plurality of conditional expressions, wherein an element of the database object is stored among a plurality of different storage regions with each storage region being associated with first and second range values indicating a value range for element values within that storage region, the computer program product comprising:

• a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising computer readable program code configured to:
• apply each conditional expression of the query predicate to at least one of the first and second range values for each of the storage regions to produce evaluation results of that conditional expression for the storage regions;
• combine the evaluation result of each conditional expression for a corresponding storage region to produce aggregated results for each of the storage regions, wherein the aggregated result for a corresponding storage region indicates at least one of satisfaction of the conditional expressions for that storage region, failure to satisfy the conditional expressions for that storage region, and insufficient information to evaluate the conditional expressions for that storage region;
• provide information to evaluate one or more conditional expressions for a storage region in response to the aggregated result for that storage region indicating insufficient information;
• and
• scan one or more corresponding individual storage regions based on the aggregated results for those storage regions.