Explicit parallelism is one of the main reasons for the poor performance of Enterprise Java Beans when building data-intensive, non-OLTP applications.
A traditional program is usually represented as a series of text instructions, which is reasonable for describing a serial system which pipes data between small, single-purpose tools that receive, process, and return.
In terms of encoding, a dataflow program might be implemented as a hash table, with uniquely identified inputs as the keys, used to look up pointers to the instructions.
[1][7][8] A pioneer dataflow language was BLOck DIagram (BLODI), published in 1961 by John Larry Kelly, Jr., Carol Lochbaum and Victor A. Vyssotsky for specifying sampled data systems.
POGOL, an otherwise conventional data-processing language developed at NSA, compiled large-scale applications composed of multiple file-to-file operations, e.g. merge, select, summarize, or transform, into efficient code that eliminated the creation of or writing to intermediate files to the greatest extent possible.
A number of offshoots of SISAL have been developed, including SAC, Single Assignment C, which tries to remain as close to the popular C programming language as possible.
The United States Navy funded development of signal processing graph notation (SPGN) and ACOS starting in the early 1980s.
[12] A more radical concept is Prograph, in which programs are constructed as graphs onscreen, and variables are replaced entirely with lines linking inputs to outputs.
[citation needed] There are many hardware architectures oriented toward the efficient implementation of dataflow programming models.