> started writing Postgres in LISP. Had to revert that decision as everything was an order of magnitude slower If they have never written a high-performance ap

> started writing Postgres in LISP. Had to revert that decision as everything was an order of magnitude slower If they have never written a high-performance application in Lisp, they would have needed a bit more work. The Lisp version was written more as an experiment: http://db.cs.berkeley.edu/papers/ERL-M90-34.pdf http://db.cs.berkeley.edu/papers/ERL-M90-34.pdf > Our feeling is that the use of LISP has been a terrible mistake for several reasons. First, current LISP environments are very large. To run a ‘‘nothing’’ program in LISP requires about 3 mbytes of address space. Hence, POSTGRES exceeds 4 mbytes in size, all but 1 mbyte is the LISP compiler, editor and assorted other non required (or even desired) functions. Hence, we suffer from a gigantic footprint. Second, a DBMS never wants to stop when garbage collection happens. Any response time sensitive pro- gram must therefore allocate and deallocate space manually, so that garbage collection never happens dur- ing normal processing. Consequently, we spent extra effort ensuring that LISP garbage collection is not used by POSTGRES. Hence, this aspect of LISP, which improves programmer productivity, was not avail- able to us. Third, LISP execution is slow. As noted in the performance figures in the next section our LISP code is more than twice as slow as the comparable C code. Of course, it is possible that we are not skilled LISP programmers or do not know how to optimize the language; hence our experience should be suitably discounted. They had problems because Lisp alone needed 3 Megabytes of address space (!) to run - a 'gigantic footprint' - , needed to work around the GC and their C version was twice as fast. Their main problem was that they wanted to write it in a mix of C with Lisp and it was hard to debug for them. I'm not surprised that people with no experience writing applications in a mix of C + Lisp failed to write a database engine. I'm pretty sure it is easier to write a database engine in C compared to a mix of C and Lisp, without GC and crossing the boundaries of a managed runtime and plain C data. People did that, but these people had quite a bit more experience writing such applications. You can buy for example AllegroGraph, a graph database in Allegro Common Lisp: https://allegrograph.com https://allegrograph.com You can bet that the NSA/CIA/Homeland Security etc. all have it running with very large datasets about you, me and all the others.