Sorting Operator Optimization

Availability

This feature is available since MogDB 3.1.0.

Introduction

This feature optimizes the sorting of a single column, adds special sorting functions, and supports incremental sorting to improve the sorting operator performance.

Benefits

This feature improves the sorting operator performance of MogDB.

Description

This feature optimizes the sorting of a single column. This features allows to save a Datum structure and does not require replication of rows to sorting memory.

MogDB uses quick sorting where each data type has a comparison function. During execution of sorting, to avoid consuming a large amount of overheads due to multiple scheduling of comparison functions, this feature adds a group of functions for quick sorting. The comparison functions of these functions are interconnected. They can reduce overheads consumed by scheduling of comparison functions to improve performance.

Additionally, this features adds an incremental sorting method. It can supports index sorting and supports incremental sorting of fields based on index sorting to reduce the number of fields to be sorted to improve performance.

Enhancements

None

Constraints

This feature supports the following sorting modes except ORDER BY LIMIT: integer, date, timestamp, uuid, text, varchar, and char.

Dependencies

None