[Pgpool-general] suggestion: auto-detect common updatable SELECTs [SumsaultRT #3219]

[Mark Stosberg]

Hello,

The documentation provides this warning about load balancing:

   Please note that a SELECT may modify databases by calling a
   updatable function. In this case you should NOT use the load
   balancing. Othewise pgpool will fail due to the contents difference
   between the master and the secondary database. You can avoid the
   load balancing by putting spaces or comments in the begining of the
   query.

Are there other common cases besides "nextval" ? Could these common
cases be automatically detected and not load-balanced?  

The difference in code between

 "SELECT NEXTVAL..."

and 

 " SELECT NEXTVAL..."

Seems prone to errors over time. 

I would like to load-balance between a Slony-I master and slave, but am
concerned about accidently corrupting the slave's state this way.

	Mark