Thanks all.
I just got some senses about how to construct and manipulate BATs, BBPs, Heap and etc with GDK, and
how commands and patterns are provided to manage BATs by bat5 and algebra, with which
basically something was done to manage primitive data.
Of course, prior to that, MAL interpreter does acquire the query and execute it.
All of them, generally make a rough similarity with the "executor" that be mentioned.
Right or not, in my eyes it is that.
Best Regards
Yel
On Mon, May 17, 2010 at 5:30 PM, Isidor Zeuner <monetdb@quidecco.de> wrote:
> > 1. The executor
> > I've ever found the executor of postgreSQL at src\backend\executor,
> > but cannot make sure where it is like that in MonetDB src.
>
> MonetDB is not PostgresSQL.
> MonetDB has a completely different architecture, both as a DBMS and as
> software package (see website & research papers for details).
>
> I don't even know what the "executor" of PostgreSQl is, let alone what it is
> used for.
>
Having also done some work using PostgreSQL, I'd say the MAL
interpreter has a rough similarity with the PostgreSQL executor as far
as both components will take some internal representation on how to
acquire the query result and execute it to create the result. However,
the comparison does not go very far as both database engines have
substantially different architectures. Some notable differences are:
MonetDB normally works on complete columns for high-speed bulk
processing. Because of this, the MAL interpreter's plan execution
will result in a fully materialized result set, while the row-based
PostgreSQL executor expects results to be pulled from it row by
row. Also, while the PostgreSQL executor does perform some local
optimizations, MonetDB will do both global and local optimizations
in different optimization pipeline components, before running the MAL
interpreter.
Best regards,
Isidor