[Samtools-help] samtools pos-to-name map for faster re-sorting?

[Henrik B. <hb...@bi...>]

Assume I have a large BAM file (foo_sorted_by_pos.bam) sorted by
chromosomal coordinates.  Occasionally, but more than once, I need to
sort this by read names (foo_sorted_by_name.bam) but I don't want to
keep the latter around (to save disk space).

Conceptually would it be possible to store a "pos-to-name index map"
that can be reused to speedup the pos-to-name sorting and that is much
smaller (than foo_sorted_by_name.bam)?  Would this work/make a
difference with the BAM file format?  If so, may I ask for it to be
put on the wishlist of things to be added?

Thanks,

Henrik