Hello，
Thank you for reading my question!
Lately，I‘am reading PostgreSQL’s source code！ As I understand，the PLs
module（such as pl/pgSQL）allow user-defined functions to be writter in other
languages.
AS "postgresql-9.0-document.pdf" says :"For a function written in a
procedurallanguage, the database server has no built-in knowledge about how to
interpret the function’s source text. Instead, the task is passed to a special
handler that knows the details of the language.The handler could either do all
the work of parsing, syntax analysis, execution, etc. itself, or it could serve
as “glue” between PostgreSQL and an existing implementation of a programming
language."
I've tried to find when and where do PG invoke PLs module,but failed.There
are four procedures for a query string--parer, rewrite,plan and execute. I want
to know which part invoke the PLs module,and which function is the entry to do
that.
Looking forward for your reply!
from
stone.
