1. A computer database reorganization method for reorganizing one set of database data blocks at a time, allowing concurrent data manipulation, comprising: identifying, by a processor an original set of data blocks for reorganization in a sliding peephole mode, wherein the original identified set of data blocks comprise a subset of data within a database, the database comprising a plurality of data blocks eligible for reorganization, a size of the original identified set of data blocks selected below a predetermined threshold size relative to the database size such that the probability of concurrent manipulations of data in the original identified set of data blocks during reorganization of the original identified set of data blocks is below a probability threshold; latching the original identified set of data blocks wherein manipulations of data in the original identified set of data blocks are not permitted during unloading of a copy of the original identified set of data blocks into a temporary workspace; unloading a copy of the set of identified original data blocks into a temporary workspace to form a copied set of data blocks; unlatching the identified original set of data blocks such that concurrent manipulations of the identified original set of data blocks are permitted during reorganization of the copied set of data blocks in the temporary workspace; re-ordering the copied set of data blocks in the temporary workspace; determining whether changes have occurred to the original identified set of data blocks during re-ordering of the copied set of data blocks; and discarding the re-ordered, copied set of data blocks in the temporary workspace in response to determining that changes have occurred to the original identified set of data blocks during re-ordering.