Fix for RM # 42861, provide a function to return code version

Add a SQL function to return code version
The function usage is as follows:

	select hdfs_fdw_version();
	 hdfs_fdw_version
	------------------
    	        20003
	(1 row)

The purpose of code version is as follows:
If the .so file is updated and the customer
just installs the update but does not do an
ALTER EXTENSION then the \dx version will still
be older but the .so will be newer.
To detect which version of .so is being used
we need a code version.

hdfs_fdw--2.0.2--2.0.3.sql

@@ -1,3 +1,5 @@
 /* hdfs_fdw/hdfs_fdw--2.0.2--2.0.3.sql */
 
--- No new functions or definitions were added in 2.0.3
+CREATE OR REPLACE FUNCTION hdfs_fdw_version()
+  RETURNS pg_catalog.int4 STRICT
+  AS 'MODULE_PATHNAME' LANGUAGE C;

hdfs_fdw--2.0.3.sql

@@ -31,3 +31,7 @@ LANGUAGE C STRICT;
 CREATE FOREIGN DATA WRAPPER hdfs_fdw
   HANDLER hdfs_fdw_handler
   VALIDATOR hdfs_fdw_validator;
+
+CREATE OR REPLACE FUNCTION hdfs_fdw_version()
+  RETURNS pg_catalog.int4 STRICT
+  AS 'MODULE_PATHNAME' LANGUAGE C;

hdfs_fdw.c

@@ -52,7 +52,14 @@ PG_MODULE_MAGIC;
 /* Default CPU cost to process 1 row  */
 #define DEFAULT_FDW_TUPLE_COST      1000.0
 
+/*
+ * In PG 9.5.1 the number will be 90501,
+ * our version is 2.0.3 so number will be 20003
+ */
+#define CODE_VERSION   20003
+
 PG_FUNCTION_INFO_V1(hdfs_fdw_handler);
+PG_FUNCTION_INFO_V1(hdfs_fdw_version);
 
 #define IS_DEBUG					0
 
@@ -100,6 +107,12 @@ static void process_query_params(int index,
 
 static void hdfs_fdw_xact_callback(XACT_CB_SIGNATURE);
 
+Datum
+hdfs_fdw_version(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT32(CODE_VERSION);
+}
+
 void
 _PG_init(void)
 {
@@ -295,6 +308,8 @@ hdfsGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid
 	}
 
 	baserel->rows = 1000;
+	fpinfo->width = 1000;
+	baserel->reltarget->width = fpinfo->width;
 
 	/* Get the actual number of rows from server
 	 * if use_remote_estimate is specified in options.
@@ -311,6 +326,9 @@ hdfsGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid
 	}
 	fpinfo->rows = baserel->tuples = baserel->rows;
 
+	fpinfo->width = 1000;
+	baserel->reltarget->width = fpinfo->width;
+
 	if (IS_DEBUG)
 		ereport(LOG, (errmsg("hdfs_fdw: hdfsGetForeignRelSize ends [%f]", baserel->rows)));
 }