-rw-rw-r-- 1 aardvark aardvark 1.2G Dec 11 15:13 junk.dat

grep -c '^>' junk.dat 
10000000

#  one-off: create database table 'junk':

time < junk.dat psql -c "drop table if exists junk;
  create table junk(accession text, sequence text);
  copy junk from stdin csv delimiter E'\t';" ;

real    1m35.215s

# one-off: create index on database table 'junk':

time echo "
  create index junk_idx on junk (accession);
  analyze junk;" | psql

real    7m58.633s