... This paper discuss the ISDC's experiences with our Data Access Layers (DAL). ... ISDC's DAL was designed to solve problems anticipated by the combination of Integral's 4 instruments, wide fields of view, many instrument modes, and new pointings approximantly every half hour. This would mean that any sensible scientific data analysis would process hundreds of individual files. ... CFITSIO is a fast efficient, easy to use library for reading and writing FITS files. ... Figure 3: DAL Indexing. ...