Refactor planner's header files.

Create a new header optimizer/optimizer.h, which exposes just the
planner functions that can be used "at arm's length", without need
to access Paths or the other planner-internal data structures defined
in nodes/relation.h.  This is intended to provide the whole planner
API seen by most of the rest of the system; although FDWs still need
to use additional stuff, and more thought is also needed about just
what selfuncs.c should rely on.

The main point of doing this now is to limit the amount of new
#include baggage that will be needed by "planner support functions",
which I expect to introduce later, and which will be in relevant
datatype modules rather than anywhere near the planner.

This commit just moves relevant declarations into optimizer.h from
other header files (a couple of which go away because everything
got moved), and adjusts #include lists to match.  There's further
cleanup that could be done if we want to decide that some stuff
being exposed by optimizer.h doesn't belong in the planner at all,
but I'll leave that for another day.

Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us

27 files changed, 28 insertions, 24 deletions

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 0d8a3f9592c..2144e14ec8d 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -35,13 +35,13 @@
 #include "optimizer/cost.h"
 #include "optimizer/geqo.h"
 #include "optimizer/inherit.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/plancat.h"
 #include "optimizer/planner.h"
 #include "optimizer/restrictinfo.h"
 #include "optimizer/tlist.h"
-#include "optimizer/var.h"
 #include "parser/parse_clause.h"
 #include "parser/parsetree.h"
 #include "partitioning/partprune.h"
diff --git a/src/backend/optimizer/path/clausesel.c b/src/backend/optimizer/path/clausesel.c
index 50452706ed1..abca03b805e 100644
--- a/src/backend/optimizer/path/clausesel.c
+++ b/src/backend/optimizer/path/clausesel.c
@@ -18,6 +18,7 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/plancat.h"
 #include "utils/fmgroids.h"
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 19be1f375c5..532de4484fa 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -83,6 +83,7 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/placeholder.h"
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c
index 6e134ae1d26..3454f129122 100644
--- a/src/backend/optimizer/path/equivclass.c
+++ b/src/backend/optimizer/path/equivclass.c
@@ -24,11 +24,11 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/appendinfo.h"
 #include "optimizer/clauses.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/planmain.h"
 #include "optimizer/restrictinfo.h"
-#include "optimizer/var.h"
 #include "utils/lsyscache.h"
 
 
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index be50d56b5a9..7e1a3908f12 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -28,12 +28,11 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
-#include "optimizer/predtest.h"
 #include "optimizer/prep.h"
 #include "optimizer/restrictinfo.h"
-#include "optimizer/var.h"
 #include "utils/builtins.h"
 #include "utils/bytea.h"
 #include "utils/lsyscache.h"
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index 9dac50ea390..56d839bb31c 100644
--- a/src/backend/optimizer/path/pathkeys.c
+++ b/src/backend/optimizer/path/pathkeys.c
@@ -21,10 +21,9 @@
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "nodes/plannodes.h"
-#include "optimizer/clauses.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
-#include "optimizer/tlist.h"
 #include "utils/lsyscache.h"
 
 
diff --git a/src/backend/optimizer/path/tidpath.c b/src/backend/optimizer/path/tidpath.c
index 94c88bd6622..466e9960119 100644
--- a/src/backend/optimizer/path/tidpath.c
+++ b/src/backend/optimizer/path/tidpath.c
@@ -40,10 +40,10 @@
 #include "catalog/pg_type.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/restrictinfo.h"
-#include "optimizer/var.h"
 
 
 /*
diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c
index 1593dbec214..a4efa693ea7 100644
--- a/src/backend/optimizer/plan/analyzejoins.c
+++ b/src/backend/optimizer/plan/analyzejoins.c
@@ -25,11 +25,11 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/joininfo.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/planmain.h"
 #include "optimizer/tlist.h"
-#include "optimizer/var.h"
 #include "utils/lsyscache.h"
 
 /* local functions */
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index c1aa0ba663b..1b4f7db649e 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -28,16 +28,15 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/paramassign.h"
 #include "optimizer/paths.h"
 #include "optimizer/placeholder.h"
 #include "optimizer/plancat.h"
 #include "optimizer/planmain.h"
-#include "optimizer/predtest.h"
 #include "optimizer/restrictinfo.h"
 #include "optimizer/subselect.h"
 #include "optimizer/tlist.h"
-#include "optimizer/var.h"
 #include "parser/parse_clause.h"
 #include "parser/parsetree.h"
 #include "partitioning/partprune.h"
diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c
index a2376d2ed7e..d6ffa7869d1 100644
--- a/src/backend/optimizer/plan/initsplan.c
+++ b/src/backend/optimizer/plan/initsplan.c
@@ -21,6 +21,7 @@
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
 #include "optimizer/joininfo.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/placeholder.h"
@@ -28,7 +29,6 @@
 #include "optimizer/planner.h"
 #include "optimizer/prep.h"
 #include "optimizer/restrictinfo.h"
-#include "optimizer/var.h"
 #include "parser/analyze.h"
 #include "rewrite/rewriteManip.h"
 #include "utils/lsyscache.h"
diff --git a/src/backend/optimizer/plan/planagg.c b/src/backend/optimizer/plan/planagg.c
index d98cb899840..86617099df0 100644
--- a/src/backend/optimizer/plan/planagg.c
+++ b/src/backend/optimizer/plan/planagg.c
@@ -35,6 +35,7 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/planmain.h"
diff --git a/src/backend/optimizer/plan/planmain.c b/src/backend/optimizer/plan/planmain.c
index f9f4b12db71..3cedd01c98b 100644
--- a/src/backend/optimizer/plan/planmain.c
+++ b/src/backend/optimizer/plan/planmain.c
@@ -23,6 +23,7 @@
 #include "optimizer/appendinfo.h"
 #include "optimizer/clauses.h"
 #include "optimizer/inherit.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/orclauses.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 5db88afd893..b2239728cf9 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -43,6 +43,7 @@
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
 #include "optimizer/inherit.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/paramassign.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
@@ -52,7 +53,6 @@
 #include "optimizer/prep.h"
 #include "optimizer/subselect.h"
 #include "optimizer/tlist.h"
-#include "optimizer/var.h"
 #include "parser/analyze.h"
 #include "parser/parsetree.h"
 #include "parser/parse_agg.h"
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 6bd3b2d1ac1..0213a376705 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -19,6 +19,7 @@
 #include "catalog/pg_type.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/planmain.h"
 #include "optimizer/planner.h"
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index 60403eef913..915c6d0cf6e 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -25,13 +25,13 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/paramassign.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/planmain.h"
 #include "optimizer/planner.h"
 #include "optimizer/prep.h"
 #include "optimizer/subselect.h"
-#include "optimizer/var.h"
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteManip.h"
 #include "utils/builtins.h"
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 1f64004cf61..9e001c1bdcb 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -29,11 +29,11 @@
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/placeholder.h"
 #include "optimizer/prep.h"
 #include "optimizer/subselect.h"
 #include "optimizer/tlist.h"
-#include "optimizer/var.h"
 #include "parser/parse_relation.h"
 #include "parser/parsetree.h"
 #include "rewrite/rewriteManip.h"
diff --git a/src/backend/optimizer/prep/prepqual.c b/src/backend/optimizer/prep/prepqual.c
index 2bd6c200cfa..e9a94976b73 100644
--- a/src/backend/optimizer/prep/prepqual.c
+++ b/src/backend/optimizer/prep/prepqual.c
@@ -33,7 +33,7 @@
 
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/prep.h"
 #include "utils/lsyscache.h"
 
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
index 0e045f171af..5392d1a561e 100644
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -44,9 +44,9 @@
 #include "access/table.h"
 #include "catalog/pg_type.h"
 #include "nodes/makefuncs.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/prep.h"
 #include "optimizer/tlist.h"
-#include "optimizer/var.h"
 #include "parser/parsetree.h"
 #include "parser/parse_coerce.h"
 #include "rewrite/rewriteHandler.h"
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 99616063f45..86c346bc389 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -34,9 +34,9 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/planmain.h"
 #include "optimizer/prep.h"
-#include "optimizer/var.h"
 #include "parser/analyze.h"
 #include "parser/parse_agg.h"
 #include "parser/parse_coerce.h"
diff --git a/src/backend/optimizer/util/orclauses.c b/src/backend/optimizer/util/orclauses.c
index c62ba88d1b2..b67158154e9 100644
--- a/src/backend/optimizer/util/orclauses.c
+++ b/src/backend/optimizer/util/orclauses.c
@@ -19,6 +19,7 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/orclauses.h"
 #include "optimizer/restrictinfo.h"
 
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index 0402ffe9a74..b57de6b4c67 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -23,13 +23,13 @@
 #include "optimizer/appendinfo.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/planmain.h"
 #include "optimizer/prep.h"
 #include "optimizer/restrictinfo.h"
 #include "optimizer/tlist.h"
-#include "optimizer/var.h"
 #include "parser/parsetree.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
diff --git a/src/backend/optimizer/util/placeholder.c b/src/backend/optimizer/util/placeholder.c
index b24478ec6f2..798aa8c5978 100644
--- a/src/backend/optimizer/util/placeholder.c
+++ b/src/backend/optimizer/util/placeholder.c
@@ -17,10 +17,10 @@
 
 #include "nodes/nodeFuncs.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/placeholder.h"
 #include "optimizer/planmain.h"
-#include "optimizer/var.h"
 #include "utils/lsyscache.h"
 
 /* Local functions */
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index 243344a0110..3efa1bdc1a4 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -35,8 +35,8 @@
 #include "nodes/makefuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/plancat.h"
-#include "optimizer/predtest.h"
 #include "optimizer/prep.h"
 #include "partitioning/partbounds.h"
 #include "parser/parse_relation.h"
diff --git a/src/backend/optimizer/util/predtest.c b/src/backend/optimizer/util/predtest.c
index ecbb0db18c3..3b260b1e3c4 100644
--- a/src/backend/optimizer/util/predtest.c
+++ b/src/backend/optimizer/util/predtest.c
@@ -21,8 +21,8 @@
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
-#include "optimizer/predtest.h"
+#include "nodes/relation.h"
+#include "optimizer/optimizer.h"
 #include "utils/array.h"
 #include "utils/inval.h"
 #include "utils/lsyscache.h"
diff --git a/src/backend/optimizer/util/restrictinfo.c b/src/backend/optimizer/util/restrictinfo.c
index c1bda812c70..1c47c708028 100644
--- a/src/backend/optimizer/util/restrictinfo.c
+++ b/src/backend/optimizer/util/restrictinfo.c
@@ -17,8 +17,8 @@
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/restrictinfo.h"
-#include "optimizer/var.h"
 
 
 static RestrictInfo *make_restrictinfo_internal(Expr *clause,
diff --git a/src/backend/optimizer/util/tlist.c b/src/backend/optimizer/util/tlist.c
index d0cc14f11d7..14d1c67a940 100644
--- a/src/backend/optimizer/util/tlist.c
+++ b/src/backend/optimizer/util/tlist.c
@@ -17,6 +17,7 @@
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/cost.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/tlist.h"
 
 
diff --git a/src/backend/optimizer/util/var.c b/src/backend/optimizer/util/var.c
index 5116d7f3490..315c81eb8e6 100644
--- a/src/backend/optimizer/util/var.c
+++ b/src/backend/optimizer/util/var.c
@@ -22,8 +22,8 @@
 
 #include "access/sysattr.h"
 #include "nodes/nodeFuncs.h"
+#include "optimizer/optimizer.h"
 #include "optimizer/prep.h"
-#include "optimizer/var.h"
 #include "parser/parsetree.h"
 #include "rewrite/rewriteManip.h"