Methods of producing nucleic acid libraries

A method for producing a nucleic acid library, comprising:

• combining:
• a nucleic acid composition comprising target nucleic acids, wherein some or all of the target nucleic acids comprise an overhang;
• and
• an oligonucleotide pool comprising oligonucleotides, wherein:
• some or all of the oligonucleotides comprise (i) a complementarity region capable of hybridizing to an overhang in a target nucleic acid, and (ii) a complementarity region identification polynucleotide,
• the oligonucleotides in the pool comprising complementarity regions include complementarity regions of different lengths, and
• the complementarity region identification polynucleotide is specific to one or more features of the complementarity region, wherein the one or more features comprise length of the complementarity region;
• under conditions in which complementarity regions in the oligonucleotides hybridize to overhangs in the target nucleic acids having a corresponding length, thereby forming hybridization products for a nucleic acid library.