Abstract: A storage and retrieval system includes at least two pairs of two confrontingly opposed, columnar arrays. Each of the pairs of columnar arrays defines a plurality of vertically spaced tray-receiving recesses, and an access region between the columns, in which an indexing/insertion/extraction mechanism is positioned for pulling bins or trays housed in the recesses. The mechanism has a platform vertically displaceable in the access regions between the pairs of arrays; a shuttle table rollably mounted upon the platform for horizontal displacement thereupon between the pairs of arrays; and an extractor assembly supported by the shuttle table for causing horizontal insertion/extraction of bins onto the shuttle table.