1. A metadata updating method based on columnar storage in a distributed file system, the method comprising: acquiring to-be-updated metadata in a data table of the distributed file system; splitting data records of the data table into multiple row groups on a row basis; converting the data table into global file metadata and multiple row group files, wherein a row group file comprises an actual data block, a data index block, a local metadata block, a metadata index block, and a file footer; and determining whether the to-be-updated metadata belongs to the global file metadata, and wherein, when the to-be-updated metadata does not belong to the global file metadata, the method further comprises: updating local metadata; and adding an updated local metadata block, an updated metadata index block, and an updated file footer to the multiple row group files according to the updated local metadata.