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Improve comments about RelOptInfo.reltargetlist.

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Tom Lane 2008-10-17 20:23:45 +00:00
parent 2a0083ede8
commit ab16485031
1 changed files with 7 additions and 5 deletions
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12
src/include/nodes/relation.h
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.160 2008/10/04 21:56:55 tgl Exp $ * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.161 2008/10/17 20:23:45 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -244,8 +244,10 @@ typedef struct PlannerInfo
* width - avg. number of bytes per tuple in the relation after the * width - avg. number of bytes per tuple in the relation after the
* appropriate projections have been done (ie, output width) * appropriate projections have been done (ie, output width)
* reltargetlist - List of Var nodes for the attributes we need to * reltargetlist - List of Var nodes for the attributes we need to
* output from this relation (in no particular order) * output from this relation (in no particular order,
* NOTE: in a child relation, may contain RowExprs * but all rels of an appendrel set must use same order)
* NOTE: in a child relation, may contain RowExpr or
* ConvertRowtypeExpr representing a whole-row Var
* pathlist - List of Path nodes, one for each potentially useful * pathlist - List of Path nodes, one for each potentially useful
* method of generating the relation * method of generating the relation
* cheapest_startup_path - the pathlist member with lowest startup cost * cheapest_startup_path - the pathlist member with lowest startup cost
@ -337,7 +339,7 @@ typedef struct RelOptInfo
int width; /* estimated avg width of result tuples */ int width; /* estimated avg width of result tuples */
/* materialization information */ /* materialization information */
List *reltargetlist; /* needed Vars */ List *reltargetlist; /* Vars to be output by scan of relation */
List *pathlist; /* Path structures */ List *pathlist; /* Path structures */
struct Path *cheapest_startup_path; struct Path *cheapest_startup_path;
struct Path *cheapest_total_path; struct Path *cheapest_total_path;
@ -350,7 +352,7 @@ typedef struct RelOptInfo
AttrNumber max_attr; /* largest attrno of rel */ AttrNumber max_attr; /* largest attrno of rel */
Relids *attr_needed; /* array indexed [min_attr .. max_attr] */ Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
int32 *attr_widths; /* array indexed [min_attr .. max_attr] */ int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
List *indexlist; List *indexlist; /* list of IndexOptInfo */
BlockNumber pages; BlockNumber pages;
double tuples; double tuples;
struct Plan *subplan; /* if subquery */ struct Plan *subplan; /* if subquery */