| 摘要 |
Data within a database object are accessed based on a query with a predicate including a plurality of conditional expressions. Elements of the database object are stored among a plurality of different storage regions along with range values for element values within each storage region. Each conditional expression of the query predicate is applied to the range values for each storage region to produce evaluation results of that conditional expression for each storage region. The evaluation result of each conditional expression for a corresponding storage region is combined to produce aggregated results for each of the storage regions, where the aggregated result for a corresponding storage region indicates results of a tri-state evaluation (e.g., true/false or unknown) of the conditional expressions for that storage region. One or more corresponding individual storage regions are scanned based on the aggregated results for those storage regions when the tri-state evaluation is unknown. |
