Donald Dong <xd...@csumb.edu> writes: > I created some empty tables and run ` EXPLAIN ANALYZE` on `SELECT * `. I found > the results have different row numbers, but the tables are all empty.
This isn't a terribly interesting case, since you've neither loaded any data nor vacuumed/analyzed the table, but ... > I found this behavior unexpected. I'm still trying to find out how/where the > planner > determines the plan_rows. ... estimate_rel_size() in plancat.c is where to look to find out about the planner's default estimates when it's lacking hard data. regards, tom lane