Abstract: A heterogeneous database storage system based on optical disk includes a magnetic disk storage device and an optical disk storage device connecting, via a data connection, to a server. A relational database management system, a non-relational database management system, a data processor and a database connector are installed on the server. Fields of a record are divided into two parts by the data processor. A part of the fields are in a relational database, and the other part of the fields are in a non-relational database. Fields of the relational database constitute a subrecord of the relational database, and Fields of the non-relational database constitute a subrecord of the non-relational database. The subrecord of the relation database and the corresponding subrecord of the non-relational database form an integral record by the database connector.

Abstract: A refrigerator comprises a case defining a storage compartment, and at least one door assembly. Each door assembly comprises: a door, arranged in front of the case and used for opening or closing the storage compartment; and at least one translation hinge. Each translation hinge has two swing arms, and two ends of each swing arm directly or indirectly mounted rotatably on the door and the case relative to the door and the case, so that each translation hinge and the door and the case form a parallelogram-shaped mechanism, allowing the door to translate to open or close the storage compartment.