2016-12-28 10:46 GMT+01:00 Pavel Stehule <pavel.steh...@gmail.com>: > Hi > > 2016-12-28 10:15 GMT+01:00 Tim Uckun <timuc...@gmail.com>: > >> I have seen various links on the internet which indicate that PLV8 is >> significantly faster than PL-PGSQL sometimes an order of magnitude faster. >> >> Is this uniformly true or is it just in certain circumstances? >> > > It depends on usage > > >> >> Is there any benefit to choosing PL-PGSQL? >> > > there are more benefits > > 0. this language has integrated SQL - the code with lot of SQL is more > readable. > 1. it is everywhere, where is Postgres > 2. it uses same data types like Postgres, there is not any conversion > related overhead > 3. this engine has quick start, faster than anything else. >
4. It is not slow language - it is AST interpret - it is significantly faster than byte code based interpreter without JIT. The expression are slower - the PostgerSQL expression interpret. This is bottle neck of PLpgSQL performance - on second hand - it is main benefit of PLpgSQL - there is full integration with PostgreSQL runtime without any exceptions. Years ago PLpgSQL has very slow operations on arrays - this was fixed in 9.5. Still PLpgSQL has slow string updates - Strings are immutable in PLpgSQL - so update means generating new string. But usually it is not bottleneck in PL environment. Regards Pavel > > >> >> Is there work going on to make PL-PGSQL more performant or has it gotten >> significantly faster in the last two years or so (some of the links are a >> from a while ago). >> > > What I know no. There is not any reason why to do it. This language is > designed be glue of SQL statements. Nothing more, nothing less. I did > tests, and it is significantly faster than SQL engine. > > Some years ago I though about compilation to C language, but the target > was better obfuscation not performance. > > PLpgSQL is not designed for hard calculation - the critical path is in SQL > always. If you need different performance, than you can use PLV8, PLPython > or native C extension. Postgres has very good API for writing C extensions. > > Regards > > Pavel > > >> >> Thanks. >> > >
