1. A database management method, comprising; dividing, by a database system, a data partition into a physical partition layer and a logical partition layer, wherein the physical partition layer is configured to store a physical partition segment of the database system, wherein the physical partition segment is a set of all data records in a partition table, wherein the logical partition layer is configured to store a logical partition segment of the database system to provide logical partition information of the partition table, and wherein the logical partition segment and the physical partition segment are mapped to each other using a mapping relationship; receiving, by the database system, a query instruction; determining a logical partition segment to which a data record queried by the query instruction belongs; determining a partition table-based query condition according to the query instruction; performing partition pruning on the logical partition segment to exclude a logical partition segment not involved in query; generating an execution plan; determining, by the database system according to the execution plan, the query instruction, and the mapping relationship, a physical partition segment that corresponds to the determined logical partition segment to obtain the data record queried by the query instruction at the physical partition layer; and returning the obtained data record as a query result.