A method for representing a database in a computer readable medium. Accessing a first table in the database. The first table has rows of data, each row of data having one or more columns. Storing a first representation of the first table in a volatile computer memory in a column-oriented format, the column-oriented format comprising at least one B-tree for at least one column, wherein the B-tree is composed of at least one array and the at least one B-tree includes references to a plurality of arrays, each array of the plurality of arrays comprised of data corresponding to the rows of one column of the table, wherein the storing further comprising storing data corresponding to the rows in a packed format. Storing a second representation of the database on the computer-readable medium, the second representation substantially identical to the first representation.