Add missing dblink files.

contrib/dblink/doc/cursor

@@ -0,0 +1,159 @@
+==================================================================
+Name
+
+dblink_open -- Opens a cursor on a remote database
+
+Synopsis
+
+dblink_open(text cursorname, text sql)
+
+Inputs
+
+  cursorname
+
+    a reference name for the cursor
+
+  sql
+
+    sql statement that you wish to execute on the remote host
+    e.g. "select * from pg_class"
+
+Outputs
+
+  Returns status = "OK"
+
+Note
+  1) dblink_connect(text connstr) must be executed first
+  2) dblink_open starts an explicit transaction. If, after using dblink_open,
+     you use dblink_exec to change data, and then an error occurs or you use
+     dblink_disconnect without a dblink_close first, your change *will* be
+     lost. Also, using dblink_close explicitly ends the transaction and thus
+     effectively closes *all* open cursors.
+
+Example usage
+
+test=# select dblink_connect('dbname=template1');
+ dblink_connect
+----------------
+ OK
+(1 row)
+
+test=# select dblink_open('foo','select proname, prosrc from pg_proc');
+ dblink_open
+-------------
+ OK
+(1 row)
+
+==================================================================
+Name
+
+dblink_fetch -- Returns a set from an open cursor on a remote database
+
+Synopsis
+
+dblink_fetch(text cursorname, int32 howmany)
+
+Inputs
+
+  cursorname
+
+    The reference name for the cursor
+
+  howmany
+
+    Maximum number of rows to retrieve. The next howmany rows are fetched,
+    starting at the current cursor position, moving forward. Once the cursor
+    has positioned to the end, no more rows are produced.
+
+Outputs
+
+  Returns setof record
+
+Example usage
+
+test=# select dblink_connect('dbname=template1');
+ dblink_connect
+----------------
+ OK
+(1 row)
+
+test=# select dblink_open('foo','select proname, prosrc from pg_proc where proname like ''bytea%''');
+ dblink_open
+-------------
+ OK
+(1 row)
+
+test=# select * from dblink_fetch('foo',5) as (funcname name, source text);
+ funcname |  source
+----------+----------
+ byteacat | byteacat
+ byteacmp | byteacmp
+ byteaeq  | byteaeq
+ byteage  | byteage
+ byteagt  | byteagt
+(5 rows)
+
+test=# select * from dblink_fetch('foo',5) as (funcname name, source text);
+ funcname  |  source
+-----------+-----------
+ byteain   | byteain
+ byteale   | byteale
+ bytealike | bytealike
+ bytealt   | bytealt
+ byteane   | byteane
+(5 rows)
+
+test=# select * from dblink_fetch('foo',5) as (funcname name, source text);
+  funcname  |   source
+------------+------------
+ byteanlike | byteanlike
+ byteaout   | byteaout
+(2 rows)
+
+test=# select * from dblink_fetch('foo',5) as (funcname name, source text);
+ funcname | source
+----------+--------
+(0 rows)
+
+==================================================================
+Name
+
+dblink_close -- Closes a cursor on a remote database
+
+Synopsis
+
+dblink_close(text cursorname)
+
+Inputs
+
+  cursorname
+
+    a reference name for the cursor
+
+Outputs
+
+  Returns status = "OK"
+
+Note
+  dblink_connect(text connstr) must be executed first.
+
+Example usage
+
+test=# select dblink_connect('dbname=template1');
+ dblink_connect
+----------------
+ OK
+(1 row)
+
+test=# select dblink_open('foo','select proname, prosrc from pg_proc');
+ dblink_open
+-------------
+ OK
+(1 row)
+
+test=# select dblink_close('foo');
+ dblink_close
+--------------
+ OK
+(1 row)
+