does DBD::mysql (or the MySQL API for that matter) support random access to BLOB types ? i.e. the ability to select/insert a BLOB via a serious of small queries, as opposed to the memory intensive approach of selecting/inserting the total contents of the column in one query.
It's unlikely that any scenario would allow you to select/insert via a serious of small queries. Some approaches might allow you to do it via a series of small queries.
