database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-05 07:21:24 +03:00
Code Activity

Implement an API to let foreign-data wrappers actually be functional.

Browse Source 
This commit provides the core code and documentation needed.  A contrib
module test case will follow shortly.

Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
This commit is contained in:
Tom Lane
2011-02-20 00:17:18 -05:00
parent d5813488a4
commit bb74240794
39 changed files with 1202 additions and 62 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
src/backend/optimizer/util/pathnode.c
View File

@ -17,6 +17,7 @@
#include <math.h>
#include "catalog/pg_operator.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
@ -1419,6 +1420,41 @@ create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel)
return pathnode;
}
/*
* create_foreignscan_path
* Creates a path corresponding to a scan of a foreign table,
* returning the pathnode.
*/
ForeignPath *
create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel)
{
ForeignPath *pathnode = makeNode(ForeignPath);
RangeTblEntry *rte;
FdwRoutine *fdwroutine;
FdwPlan *fdwplan;
pathnode->path.pathtype = T_ForeignScan;
pathnode->path.parent = rel;
pathnode->path.pathkeys = NIL; /* result is always unordered */
/* Get FDW's callback info */
rte = planner_rt_fetch(rel->relid, root);
fdwroutine = GetFdwRoutineByRelId(rte->relid);
/* Let the FDW do its planning */
fdwplan = fdwroutine->PlanForeignScan(rte->relid, root, rel);
if (fdwplan == NULL || !IsA(fdwplan, FdwPlan))
elog(ERROR, "foreign-data wrapper PlanForeignScan function for relation %u did not return an FdwPlan struct",
rte->relid);
pathnode->fdwplan = fdwplan;
/* use costs estimated by FDW */
pathnode->path.startup_cost = fdwplan->startup_cost;
pathnode->path.total_cost = fdwplan->total_cost;
return pathnode;
}
/*
* create_nestloop_path
* Creates a pathnode corresponding to a nestloop join between two