I'm currently trying to merge two very large (11 million rows) tables, and my query has been running for over two days with no end in sight.
My basic query is:
UPDATE us_demand SET ... FROM us_demand_addtl AS sub WHERE us_demand.geoid10=sub.geoid10;
The tables each have a spatial column that is indexed (but not one of the updated columns), and geoid10 is NOT indexed in either table.
2x 7200RPM 1tb Drives in Raid
Intel i74790k - 4.00ghz quad core
32gb of RAM
I have two questions. Why is this operation so slow, and what can I do to speed it up?