Review visibility of database changes.

[strk]

While implementing plpgsql functions to add complex objects into a topology I realized that items added by other topology functions are not visible by queries of outer functions.

I suspect this has to do with STABLE/VOLATILE, but I could be wrong.

[strk]

From ​http://www.postgresql.org/docs/8.3/static/spi-visibility.html

All standard procedural languages set the SPI read-write mode depending on the volatility attribute of the function. Commands of STABLE and IMMUTABLE functions are done in read-only mode, while commands of VOLATILE functions are done in read-write mode. While authors of C functions are able to violate this convention, it's unlikely to be a good idea to do so.

[strk]

Seems all good to me, after review. The issue I was after was unrelated..