minor create_remotequery_path improvement, rename RemoteQueryPath fields

The RemoteQueryPath structure includes three flags tracking features of
the path - originally, those were called

- rqhas_unshippable_qual
- rqhas_temp_rel
- rqhas_unshippable_tlist

which is a bit awkward because we already know it's part of RemoteQuery,
so the 'rq' prefix is redundant. So I've renamed them to

- has_unshippable_qual
- has_temp_rel
- has_unshippable_tlist

Also, reformat/reword the comment a bit.

diff --git a/src/backend/optimizer/path/pgxcpath.c b/src/backend/optimizer/path/pgxcpath.c
index ad115ff77e3a6c89b8b5dd9290901d7e820f78e6..0d2385c43bf8607077236fd5e3ac2388a27892fc 100644 (file)
--- a/src/backend/optimizer/path/pgxcpath.c
+++ b/src/backend/optimizer/path/pgxcpath.c
@@ -28,17 +28,21 @@ static RemoteQueryPath *create_remotequery_path(PlannerInfo *root, RelOptInfo *r
                                                                List *join_restrictlist);
 /*
  * create_remotequery_path
- *       Creates a path for given RelOptInfo (for base rel or a join rel) so that
- *       the results corresponding to this RelOptInfo are obtained by querying
- *       datanode/s. When RelOptInfo represents a JOIN, we leftpath and rightpath
- *       represents the RemoteQuery paths for left and right relations resp,
- *       jointype gives the type of JOIN and join_restrictlist gives the
- *       restrictinfo list for the JOIN. For a base relation, these should be
- *       NULL.
- *       ExecNodes is the set of datanodes to which the query should be sent to.
- *       This function also marks the path with shippability of the quals.
- *       If any of the relations involved in this path is a temporary relation,
- *       record that fact.
+ *       Creates a RemoteQuery path for a given RelOptInfo.
+ *
+ * The path buils the RelOptInfo data by querying datanode(s). For RelOptInfo
+ * representing a JOIN, the left/right paths represent the RemoteQuery paths
+ * for left and right relations, the jointype identifies the type of JOIN, and
+ * join_restrictlist contains the restrictinfo list for the JOIN.
+ *
+ * For a base relation, these parameters should be NULL.
+ *
+ * ExecNodes is the set of datanodes to which the query should be sent to.
+ *
+ * This function also marks the path with shippability of the quals.
+ *
+ * If any of the relations involved in this path is a temporary relation,
+ * record that fact.
  */
 static RemoteQueryPath *
 create_remotequery_path(PlannerInfo *root, RelOptInfo *rel, ExecNodes *exec_nodes,
@@ -55,7 +59,7 @@ create_remotequery_path(PlannerInfo *root, RelOptInfo *rel, ExecNodes *exec_node
        rqpath->path.parent = rel;
        /* PGXC_TODO: do we want to care about it */
        rqpath->path.param_info = NULL;
-       rqpath->path.pathkeys = NIL;    /* result is always unordered */
+       rqpath->path.pathkeys = NIL;    /* result is always unsorted */
        rqpath->rqpath_en = exec_nodes;
        rqpath->leftpath = leftpath;
        rqpath->rightpath = rightpath;
@@ -71,7 +75,7 @@ create_remotequery_path(PlannerInfo *root, RelOptInfo *rel, ExecNodes *exec_node
                        if (rte->rtekind != RTE_RELATION)
                                elog(ERROR, "can not create remote path for ranges of type %d",
                                                        rte->rtekind);
-                       rqpath->rqhas_temp_rel = IsTempTable(rte->relid);
+                       rqpath->has_temp_rel = IsTempTable(rte->relid);
                        unshippable_quals = !pgxc_is_expr_shippable((Expr *)extract_actual_clauses(rel->baserestrictinfo, false),
                                                                                                                NULL);
                }
@@ -79,8 +83,8 @@ create_remotequery_path(PlannerInfo *root, RelOptInfo *rel, ExecNodes *exec_node
 
                case RELOPT_JOINREL:
                {
-                       rqpath->rqhas_temp_rel = leftpath->rqhas_temp_rel ||
-                                                                       rightpath->rqhas_temp_rel;
+                       rqpath->has_temp_rel = leftpath->has_temp_rel ||
+                                                                       rightpath->has_temp_rel;
                        unshippable_quals = !pgxc_is_expr_shippable((Expr *)extract_actual_clauses(join_restrictlist, false),
                                                                                                                NULL);
                }
@@ -90,7 +94,8 @@ create_remotequery_path(PlannerInfo *root, RelOptInfo *rel, ExecNodes *exec_node
                        elog(ERROR, "can not create remote path for relation of type %d",
                                                        rel->reloptkind);
        }
-       rqpath->rqhas_unshippable_qual = unshippable_quals;
+
+       rqpath->has_unshippable_qual = unshippable_quals;
 
        /* PGXCTODO - set cost properly */
        cost_remotequery(rqpath, root, rel);
@@ -191,7 +196,7 @@ create_joinrel_rqpath(PlannerInfo *root, RelOptInfo *joinrel,
         * but evaluating the qual on join result. But we don't attempt it for now
         */
        if (!innerpath || !outerpath ||
-               innerpath->rqhas_unshippable_qual || outerpath->rqhas_unshippable_qual)
+               innerpath->has_unshippable_qual || outerpath->has_unshippable_qual)
                return;
 
        inner_en = innerpath->rqpath_en;

diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index da103ce487c86e1eea7351e0165b36a493239472..90707640667e5ca9c6054a1912361caa84eb5446 100644 (file)
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -1181,6 +1181,7 @@ typedef struct RemoteQueryPath
 {
        Path                    path;
        ExecNodes               *rqpath_en;             /* List of datanodes to execute the query on */
+
        /*
         * If the path represents a JOIN rel, leftpath and rightpath represent the
         * RemoteQuery paths for left (outer) and right (inner) side of the JOIN
@@ -1194,15 +1195,15 @@ typedef struct RemoteQueryPath
                                                                                                 * the JOIN information is
                                                                                                 * available
                                                                                                 */
-       bool                                    rqhas_unshippable_qual; /* TRUE if there is at least
+       bool                                    has_unshippable_qual;   /* TRUE if there is at least
                                                                                                         * one qual which can not be
                                                                                                         * shipped to the datanodes
                                                                                                         */
-       bool                                    rqhas_temp_rel;                 /* TRUE if one of the base relations
+       bool                                    has_temp_rel;                   /* TRUE if one of the base relations
                                                                                                         * involved in this path is a temporary
                                                                                                         * table.
                                                                                                         */
-       bool                                    rqhas_unshippable_tlist;/* TRUE if there is at least one
+       bool                                    has_unshippable_tlist;  /* TRUE if there is at least one
                                                                                                         * targetlist entry which is
                                                                                                         * not completely shippable.
                                                                                                         */