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 0d8a3f9592..2144e14ec8 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 50452706ed..abca03b805 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 19be1f375c..532de4484f 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 6e134ae1d2..3454f12912 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 be50d56b5a..7e1a3908f1 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 9dac50ea39..56d839bb31 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 94c88bd662..466e996011 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 1593dbec21..a4efa693ea 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 c1aa0ba663..1b4f7db649 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 a2376d2ed7..d6ffa7869d 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 d98cb89984..86617099df 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 f9f4b12db7..3cedd01c98 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 5db88afd89..b2239728cf 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 6bd3b2d1ac..0213a37670 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 60403eef91..915c6d0cf6 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 1f64004cf6..9e001c1bdc 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 2bd6c200cf..e9a94976b7 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 0e045f171a..5392d1a561 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 99616063f4..86c346bc38 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 c62ba88d1b..b67158154e 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 0402ffe9a7..b57de6b4c6 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 b24478ec6f..798aa8c597 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 243344a011..3efa1bdc1a 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 ecbb0db18c..3b260b1e3c 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 c1bda812c7..1c47c70802 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 d0cc14f11d..14d1c67a94 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 5116d7f349..315c81eb8e 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"