Re: MPI programming in postgreSQL backend source code

On 11/09/2011 04:10 PM, Rudyar Cortés wrote:
> I'm a new programmer in postgreSQL source code..
> Is possible use MPI functions in postgreSQL source code?

To do this the proper way, you would need to modify the database's 
"configure" step to:

-Check if the OpenMPI libraries are available and include the necessary 
bits.  For example, this is in one of the projects I work on:

#ifdef _OPENMP
extern int omp_get_num_threads();
#endif

Some form of that test and defining the functions available would be 
needed for what you want.

-Link OpenMPI in.  At the gcc level you'll need "-fopenmp" to start.

Then you could start using OpenMPI functions in database code.  You 
might hack the build steps to do this in a simpler way, too, rather than 
fight with configure the proper way.

Since a lot of the MPI functions aim at specific types of thread use and 
I/O, it would be a major effort to utilize the library for too many 
things.  The existing notion of how processes are created and managed is 
scattered throughout the PostgreSQL code.  And the I/O parts of the 
database are buried through a few layers of indirection.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us