srf_index_hash(1)
Adds a hash-table index to an SRF file.
Description
srf_index_hash
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