My first convolution on the G machine

insert into result select key,link,pointer from other;
insert into result select key,link,pointer from self;

Concatenation. I put that operator in the config table, to be loaded and prepped. The G engine came up and popped the first node from config. It followed the installs triple until the next triple pulled was a direct execution of the installed operator.

Concatenation doesn't work in the general case, for G graphs. But for list of nearly the same width, they work OK, even with slightly different nesting pattern in each list. Using the rank and file indexing, with operator properties, SQL can do a great job of passing triples at ultra high speed.