The makeudb_usearch command creates a UDB database file from sequences in a FASTA file. Index parameters are set to defaults for usearch_global and usearch_local. These defaults can be overridden by specifying index parameters on the command line.
Example
usearch -makeudb_usearch db.fasta -output db.udb
usearch -makeudb_usearch db.fasta -output db.udb -wordlength
12 -dbstep 4