);
COPY t2 FROM stdin;
CREATE FOREIGN TABLE ft1 (
- c1 integer OPTIONS (colname 'invalid'),
- c2 text OPTIONS (colname 'C2'),
+ c1 integer,
+ c2 text,
c3 date
) SERVER loopback1 OPTIONS (relname 't1');
-ALTER FOREIGN TABLE ft1 ALTER COLUMN c1 OPTIONS (SET colname 'C1');
-ALTER FOREIGN TABLE ft1 ALTER COLUMN c2 OPTIONS (DROP colname);
CREATE FOREIGN TABLE ft2 (
c1 integer,
c2 text,
SELECT * FROM ft2 ORDER BY c1; -- ERROR
ERROR: could not execute foreign query
DETAIL: ERROR: relation "public.invalid" does not exist
-LINE 1: SELECT c1, c2, c3 FROM public.invalid ft2
+LINE 1: SELECT c1, c2, c3 FROM public.invalid
^
-HINT: SELECT c1, c2, c3 FROM public.invalid ft2
+HINT: SELECT c1, c2, c3 FROM public.invalid
ALTER FOREIGN TABLE ft2 OPTIONS (SET relname 't2');
SELECT * FROM ft2 ORDER BY c1;
c1 | c2 | c3
13 | buz | 01-03-1970
(3 rows)
+-- query with projection
+SELECT c1 FROM ft1 ORDER BY c1;
+ c1
+----
+ 1
+ 2
+ 3
+(3 rows)
+
-- join two foreign tables
SELECT * FROM ft1 JOIN ft2 ON (ft1.c1 = ft2.c1) ORDER BY ft1.c1;
c1 | c2 | c3 | c1 | c2 | c3
-- WHERE clause push-down
set client_min_messages = debug1;
SELECT * FROM ft1 WHERE c1 = 1 AND c2 = lower('FOO') AND c3 < now();
-DEBUG: deparsed SQL is "SELECT C1, c2, c3 FROM public.t1 ft1 WHERE ((c1 = 1) AND (c2 = 'foo'::text))"
+DEBUG: deparsed SQL is "SELECT C1, c2, c3 FROM public.t1 WHERE ((c1 = 1) AND (c2 = 'foo'::text))"
c1 | c2 | c3
----+-----+------------
1 | foo | 01-01-1970
* postgresql_fdw.c
* foreign-data wrapper for PostgreSQL
*
- * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ * Portions Copyright (c) 2010-2011, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/postgresql_fdw/postgresql_fdw.c
static void pgEndForeignScan(ForeignScanState *node);
/* helper for deparsing a request into SQL statement */
-static void estimate_costs(PlannerInfo *root, RelOptInfo *baserel, Cost *startup_cost, Cost *total_cost);
+static void estimate_costs(PlannerInfo *root, RelOptInfo *baserel,
+ Cost *startup_cost, Cost *total_cost);
static bool is_foreign_qual(PlannerInfo *root, RelOptInfo *baserel, Expr *expr);
static bool foreign_qual_walker(Node *node, void *context);
-static char *deparseSql(Oid foreigntableid, PlannerInfo *root, RelOptInfo *baserel);
+static char *deparseSql(Oid foreigntableid, PlannerInfo *root,
+ RelOptInfo *baserel);
static void storeResult(TupleTableSlot *slot, PGresult *res, int rowno);
*/
typedef struct PgsqlFdwExecutionState
{
- PGconn *conn;
- PGresult *res;
- int nextrow;
+ PGconn *conn; /* connection used for the scan */
+ PGresult *res; /* result of the scan, held until the scan ends */
+ int nextrow; /* row index to be returned in next fetch */
} PgsqlFdwExecutionState;
context = deparse_context_for("foreigntable", foreigntableid);
/* Collect used columns from restrict information and target list */
+ attr_used = list_union(attr_used, baserel->reltargetlist);
foreach (lc, baserel->baserestrictinfo)
{
List *l;
l = pull_var_clause((Node *) ri->clause, PVC_RECURSE_PLACEHOLDERS);
attr_used = list_union(attr_used, l);
}
- attr_used = list_union(attr_used, baserel->reltargetlist);
/* deparse SELECT target list */
appendStringInfoString(&sql, "SELECT ");
first = true;
- for (attr = baserel->min_attr; attr < baserel->max_attr; attr++)
+ for (attr = 1; attr <= baserel->max_attr; attr++)
{
Var *var;
- /* System columns cannot be retrieved from remote. */
- if (attr < 0)
- continue;
-
/* Separete columns with comma. */
if (!first)
appendStringInfoString(&sql, ", ");
first = false;
- /* Use "NULL" for column which isn't in reltargetlist. */
+ /* Use "NULL" for unused columns.*/
foreach (lc, attr_used)
{
var = lfirst(lc);
else
appendStringInfo(&sql, "NULL");
}
- if (strcmp(sql.data, "SELECT ") == 0)
- {
- ereport(DEBUG1, (errmsg("targetlist is empty, retrieve all columns")));
- appendStringInfo(&sql, "*");
- }
/*
* Deparse FROM
/*
* Initiate actual scan on a foreign table.
- * This function is called just after pgOpen() if the ForeignScan was executed
- * for a real query or EXPLAIN statement with ANALYZE option.
*/
static void
pgBeginForeignScan(ForeignScanState *node, int eflags)
bool isvarlena;
FmgrInfo func;
- /* TODO: cache FmgrInfo to use it again after pgReOpen() */
/* TODO: send parameters in binary format rather than text */
getTypeOutputInfo(types[i], &out_func_oid, &isvarlena);
fmgr_info(out_func_oid, &func);
{
PgsqlFdwExecutionState *festate = (PgsqlFdwExecutionState *) node->fdw_state;
+ if (festate == NULL)
+ return;
+
PQclear(festate->res);
pfree(festate);
}
j++;
}
- /* build the tuple and put it into the tuplestore. */
+ /*
+ * Build the tuple and put it into the slot.
+ * We don't have to free the tuple explicitly because it's been
+ * allocated in the per-tuple context.
+ */
tuple = BuildTupleFromCStrings(attinmeta, values);
- ExecStoreTuple(tuple, slot, InvalidBuffer, true);
+ ExecStoreTuple(tuple, slot, InvalidBuffer, false);
}
- /* clean up and return the tuplestore */
- tuplestore_donestoring(tupstore);
pfree(values);
}
#endif
/*
- * Clean the connection up via ResourceOwner when pgClose couldn't close the
- * connection gracefully.
+ * Clean the connection up via ResourceOwner.
*/
static void
cleanup_connection(ResourceReleasePhase phase,
{
ConnCacheEntry *entry = (ConnCacheEntry *) arg;
- /*
- * If the transaction was committed, the connection has been closed via
- * pgClose() and ReleaseConnection().
- */
+ /* If the transaction was committed, don't close connections. */
if (isCommit)
return;
projects / users / hanada / postgres.git / commitdiff