On Fri, 25 Jul 2003, Maksim Likharev wrote: > I have 2 queries, one is never returns, like explain shows 677195846.00 > cost > and another doing the same job works ( cost 6072.00 ) > > I do not understand one thing, why query number one, generates so > unbelievably > screwed up plan? > > why it does not use index? > > query # 1: > ------------------------------------------------------------------------ > ------ > explain update prod.t_results set expdate=e.termdate from > work.termdate e, prod.t_results r where e.docid=r.docid;
This is almost certainly not what you meant. You haven't constrained the update table (t_results) to the results of the from. Adding t_results r to the from joins an additional copy of the table (it's not an alias for the update table). Why not just update prod.tresults set expdate=e.termdate from work.termdate where e.docid=t_results.docid; ? ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
