2015/03/23 9:12、Kouhei Kaigai <kai...@ak.jp.nec.com> のメール：
> Sorry for my response late. It was not easy to code during business trip. > > The attached patch adds a hook for FDW/CSP to replace entire join-subtree > by a foreign/custom-scan, according to the discussion upthread. > > GetForeignJoinPaths handler of FDW is simplified as follows: > typedef void (*GetForeignJoinPaths_function) (PlannerInfo *root, > RelOptInfo *joinrel); It’s not a critical issue but I’d like to propose to rename add_joinrel_extra_paths() to add_extra_paths_to_joinrel(), because the latter would make it more clear that it does extra work in addition to add_paths_to_joinrel(). > It takes PlannerInfo and RelOptInfo of the join-relation to be replaced > if available. RelOptInfo contains 'relids' bitmap, so FDW driver will be > able to know the relations to be involved and construct a remote join query. > However, it is not obvious with RelOptInfo to know how relations are joined. > > The function below will help implement FDW driver that support remote join. > > List * > get_joinrel_broken_down(PlannerInfo *root, RelOptInfo *joinrel, > SpecialJoinInfo **p_sjinfo) > > It returns a list of RelOptInfo to be involved in the relations join that > is represented with 'joinrel', and also set a SpecialJoinInfo on the third > argument if not inner join. > In case of inner join, it returns multiple (more than or equal to 2) > relations to be inner-joined. Elsewhere, it returns two relations and > a valid SpecialJoinInfo. As far as I tested, it works fine for SEMI and ANTI. # I want dump function of BitmapSet for debugging, as Node has nodeToString()... > At this moment, I'm not 100% certain about its logic. Especially, I didn't > test SEMI- and ANTI- join cases yet. > However, time is money - I want people to check overall design first, rather > than detailed debugging. Please tell me if I misunderstood the logic to break > down join relations. With applying your patch, regression tests of “updatable view” failed. regression.diff contains some errors like this: ! ERROR: could not find RelOptInfo for given relids Could you check that? — Shigeru HANADA -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
