I want to get a list of length and submission date of all known proteins of the ncbi protein data base.

The query I came up with is the following:

$ esearch -db protein -query "[PROT]" |\
  efetch -format docsum |\
  xtract -pattern DocumentSummary -element Slen CreateDate > protein_length_time.ssv

I would like to know if this will give me the desired result. Especially if this is the best way to get all proteins from the data base.

Thanks

John