NT database update (number of files)

Question

[anasofiamoreira94]

We started to perform a blast analysis with the v5 version, but we detected a problem with this DB. So we downloaded the v4. However, with this version I can no longer filter my blast to some ID seqs. I have some questions regarding blastDB: 1- If I want to download, again, the most recent version of nt DB, I should download those present in here: https://ftp.ncbi.nlm.nih.gov/blast/db/. However, to nt database I only get 22 files, is this normal? Cause the previous version of v5 add about 60 files. Thanks

Answer 1

[GenoMax]

Yes the current db at FTP link seems to have 22 files for nt. That said there have been rare instances when the database files on FTP link have been incomplete. I suggest that you check in a day or so to see if that number goes back up. You could email blast help but before they get around to responding the problem may be fixed.

Best option to deal with blast database downloads is to use the update_blastdb.pl script that is included with blast+ package.

Edit: Emailed blast product manager at NCBI. Will post an update once if I hear back.

[massa.kassa.sc3na]

You may notice, that current nt.xx.tar.gz has almost 3GB which is about 3 times the size of the old nt part.

[GenoMax]

NCBI confirmed that this is indeed the reason for smaller number of files.

[anasofiamoreira94]

Thank you so much for the help genomax