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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2012-08-26 22:48:55 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2012-08-26 22:50:23 -0400 |
| commit | 9ff79b9d4e71822a875c0f5e38f5ec86c7fb079f (patch) | |
| tree | 54ca663a626498195754d48a9b4d2c545210381d /src/include/optimizer/planmain.h | |
| parent | de87d4704432e98a327dbf42dbc4711fa2628a9c (diff) | |
| download | postgresql-9ff79b9d4e71822a875c0f5e38f5ec86c7fb079f.tar.gz postgresql-9ff79b9d4e71822a875c0f5e38f5ec86c7fb079f.zip | |
Fix up planner infrastructure to support LATERAL properly.
This patch takes care of a number of problems having to do with failure
to choose valid join orders and incorrect handling of lateral references
pulled up from subqueries. Notable changes:
* Add a LateralJoinInfo data structure similar to SpecialJoinInfo, to
represent join ordering constraints created by lateral references.
(I first considered extending the SpecialJoinInfo structure, but the
semantics are different enough that a separate data structure seems
better.) Extend join_is_legal() and related functions to prevent trying
to form unworkable joins, and to ensure that we will consider joins that
satisfy lateral references even if the joins would be clauseless.
* Fill in the infrastructure needed for the last few types of relation scan
paths to support parameterization. We'd have wanted this eventually
anyway, but it is necessary now because a relation that gets pulled up out
of a UNION ALL subquery may acquire a reltargetlist containing lateral
references, meaning that its paths *have* to be parameterized whether or
not we have any code that can push join quals down into the scan.
* Compute data about lateral references early in query_planner(), and save
in RelOptInfo nodes, to avoid repetitive calculations later.
* Assorted corner-case bug fixes.
There's probably still some bugs left, but this is a lot closer to being
real than it was before.
Diffstat (limited to 'src/include/optimizer/planmain.h')
| -rw-r--r-- | src/include/optimizer/planmain.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h index 5a9e677f94f..c395d4292c8 100644 --- a/src/include/optimizer/planmain.h +++ b/src/include/optimizer/planmain.h @@ -94,6 +94,8 @@ extern void add_base_rels_to_query(PlannerInfo *root, Node *jtnode); extern void build_base_rel_tlists(PlannerInfo *root, List *final_tlist); extern void add_vars_to_targetlist(PlannerInfo *root, List *vars, Relids where_needed, bool create_new_ph); +extern void find_lateral_references(PlannerInfo *root); +extern void create_lateral_join_info(PlannerInfo *root); extern List *deconstruct_jointree(PlannerInfo *root); extern void distribute_restrictinfo_to_rels(PlannerInfo *root, RestrictInfo *restrictinfo); |