A method and apparatus for reducing memory requirements in a computing environment. The method includes reducing the size of a header for a data structure by creating a header consisting of index information. Alternatively, the header may also include garbage collection information. The invention also provides a data structure for an object-oriented programming environment. The data structure includes: 1) a header consisting of index information and 2) one or more fields. Unlike prior data structures the header does not include information regarding the data structure's size; where it references are; it dispatch table; hash code information; or monitor information.