Generating a document index comprises: obtaining a document to be indexed; determining whether each monadic partition obtained from the document is a filter character and if so, forming a polynary partition with the monadic partition and at least one adjacent monadic partition and indexing the polynary partition, otherwise, indexing the monadic partition. Querying data comprising: receiving a data query, determining whether each monadic partition obtained from the data query is a filter character and if so, forming a polynary partition with the monadic partition and at least one adjacent monadic partition and using the polynary partition to obtain search results, otherwise, using the monadic partition to obtain search results; and combining search results to form a final query search result.