On 17 March 2016 at 18:05, David Rowley <david.row...@2ndquadrant.com> wrote: > Updated patch attached.
Please disregard 0001-Allow-aggregation-to-happen-in-parallel_2016-03-17.patch. This contained a badly thought through last minute change to how the Gather path is generated and is broken. I played around with ways of generating the Gather node as create_gather_path() is not really geared up for what's needed here, since grouped_rel cannot be passed into create_gather_path() since it contains the final aggregate PathTarget rather than the partial PathTarget, and also incorrect row estimates. I've ended up with an extra double *rows argument in this function to make it possible to override the rows from rel. I'm not sure how this'll go down... It does not seem perfect. In the end I've now added a new upper planner type to allow me to create a RelOptInfo for the partial aggregate relation, so that I can pass create_gather_path() a relation with the correct PathTarget. This seemed better than borrowing grouped_rel, then overriding the reltarget after create_gather_path() returned. Although I'm willing to consider the option that someone will disagree with how I've done things here. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
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