srf_index_hash(1)
NAME
srf_index_hash - Adds a hash-table index to an SRF file.
SYNOPSIS
srf_index_hash [-c] srf_archive
DESCRIPTION
srf_index_hash adds and index to an SRF file or replaces an existing
index with a new one. In the case of concatenated SRF files only the
index at the end of a file will be replaced, but internal indices will
not be consulted by SRF tools.
The index is a hash table indexing the sequence names only. The name
itself does not appear in the index, rather the top 7-bits of a 64-bit
hash key are held in the index along with N-bits used to determine the
hash bucket. This reduces the index size to around 10-15 bytes per
sequence.
OPTIONS
- -c Check only. This requests that the index is not produced, but
- the checks performed during the creation of an index (such as looking for duplicate sequence names) are still performed.
AUTHOR
- James Bonfield, Wellcome Trust Sanger Institute