Data sorting method and device for relational database

The invention discloses a relational database data sorting method and device, which is applied to a processing environment with a plurality of sorting processes, and comprises the following steps of: based on the size of an available memory, distributing a use memory of the sorting process for each sorting process participating in sorting; dividing a to-be-sorted data file into a plurality of data blocks based on the used memory of the sorting process; dividing the data file to be sorted into at least two parts of data; reading a data block from the part of data for sorting by utilizing two sorting processes; and merging the ordered files output by each sorting process to obtain a sorted file. According to the embodiment of the invention, external sorting is changed into parallel execution and is divided into a plurality of sorting processes, and the steps of reading, sorting and writing out are executed in parallel, so that the sorting performance can be greatly improved under new hardware, a special data re