Embodiments include methods and devices for identifying record schemas in a non-relational database by assigning a record to a schema bucket according to structural characteristics of the record and identifying a record schema of the record within the schema bucket so that records with isomorphic record schemas in the non-relational database can be determined. Aspects also include encoding keys of a lowest level of a record according to a global codemap, sorting the keys of the lowest level that belong to different parent keys respectively and updating key names of corresponding parent keys in the parent level of a children level according to the codes of the keys of the children level.