diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 80b551e78c..69ac7c0416 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -17811,43 +17811,63 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
      <tbody>
       <row>
        <entry>
-        <literal><function>pg_ls_dir(<parameter>dirname</> <type>text</>)</function></literal>
+        <literal><function>pg_ls_dir(<parameter>dirname</> <type>text</> [, <parameter>missing_ok</> <type>boolean</>, <parameter>include_dot_dirs</> <type>boolean</>])</function></literal>
        </entry>
        <entry><type>setof text</type></entry>
-       <entry>List the contents of a directory</entry>
+       <entry>
+        List the contents of a directory.
+       </entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_read_file(<parameter>filename</> <type>text</> [, <parameter>offset</> <type>bigint</>, <parameter>length</> <type>bigint</>])</function></literal>
+        <literal><function>pg_read_file(<parameter>filename</> <type>text</> [, <parameter>offset</> <type>bigint</>, <parameter>length</> <type>bigint</> [, <parameter>missing_ok</> <type>boolean</>] ])</function></literal>
        </entry>
        <entry><type>text</type></entry>
-       <entry>Return the contents of a text file</entry>
+       <entry>
+        Return the contents of a text file.
+       </entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_read_binary_file(<parameter>filename</> <type>text</> [, <parameter>offset</> <type>bigint</>, <parameter>length</> <type>bigint</>])</function></literal>
+        <literal><function>pg_read_binary_file(<parameter>filename</> <type>text</> [, <parameter>offset</> <type>bigint</>, <parameter>length</> <type>bigint</> [, <parameter>missing_ok</> <type>boolean</>] ])</function></literal>
        </entry>
        <entry><type>bytea</type></entry>
-       <entry>Return the contents of a file</entry>
+       <entry>
+        Return the contents of a file.
+       </entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_stat_file(<parameter>filename</> <type>text</>)</function></literal>
+        <literal><function>pg_stat_file(<parameter>filename</> <type>text</>[, <parameter>missing_ok</> <type>boolean</type>])</function></literal>
        </entry>
        <entry><type>record</type></entry>
-       <entry>Return information about a file</entry>
+       <entry>
+        Return information about a file.
+       </entry>
       </row>
      </tbody>
     </tgroup>
    </table>
 
+   <para>
+    All of these functions take an optional <parameter>missing_ok</> parameter,
+    which specifies the behaviour when the file or directory does not exist.
+    If <literal>true</literal>, the function returns NULL (except
+    <function>pg_ls_dir</>, which returns an empty result set). If
+    <literal>false</>, an error is raised. The default is <literal>false</>.
+   </para>
+
    <indexterm>
     <primary>pg_ls_dir</primary>
    </indexterm>
    <para>
-    <function>pg_ls_dir</> returns all the names in the specified
-    directory, except the special entries <quote><literal>.</></> and
-    <quote><literal>..</></>.
+    <function>pg_ls_dir</> returns the names of all files (and directories
+    and other special files) in the specified directory. The <parameter>
+    include_dot_dirs</> indicates whether <quote>.</> and <quote>..</> are
+    included in the result set. The default is to exclude them
+    (<literal>false/>), but including them can be useful when
+    <parameter>missing_ok</> is <literal>true</literal>, to distinguish an
+    empty directory from an non-existent directory.
    </para>
 
    <indexterm>
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 5cc74d03c1..2b1dcd0d19 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -25,6 +25,8 @@
 
 #include <dirent.h>
 #include <limits.h>
+#include <sys/file.h>
+#include <sys/stat.h>
 #include <unistd.h>
 
 #include "access/htup_details.h"
@@ -51,6 +53,7 @@
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
 #include "utils/tqual.h"
@@ -103,6 +106,7 @@ static void ApplyExtensionUpdates(Oid extensionOid,
 					  ExtensionControlFile *pcontrol,
 					  const char *initialVersion,
 					  List *updateVersions);
+static char *read_whole_file(const char *filename, int *length);
 
 
 /*
@@ -635,12 +639,11 @@ read_extension_script_file(const ExtensionControlFile *control,
 						   const char *filename)
 {
 	int			src_encoding;
-	bytea	   *content;
 	char	   *src_str;
 	char	   *dest_str;
 	int			len;
 
-	content = read_binary_file(filename, 0, -1);
+	src_str = read_whole_file(filename, &len);
 
 	/* use database encoding if not given */
 	if (control->encoding < 0)
@@ -649,21 +652,15 @@ read_extension_script_file(const ExtensionControlFile *control,
 		src_encoding = control->encoding;
 
 	/* make sure that source string is valid in the expected encoding */
-	len = VARSIZE_ANY_EXHDR(content);
-	src_str = VARDATA_ANY(content);
 	pg_verify_mbstr_len(src_encoding, src_str, len, false);
 
-	/* convert the encoding to the database encoding */
+	/*
+	 * Convert the encoding to the database encoding. read_whole_file
+	 * null-terminated the string, so if no conversion happens the string is
+	 * valid as is.
+	 */
 	dest_str = pg_any_to_server(src_str, len, src_encoding);
 
-	/* if no conversion happened, we have to arrange for null termination */
-	if (dest_str == src_str)
-	{
-		dest_str = (char *) palloc(len + 1);
-		memcpy(dest_str, src_str, len);
-		dest_str[len] = '\0';
-	}
-
 	return dest_str;
 }
 
@@ -3008,3 +3005,49 @@ ExecAlterExtensionContentsStmt(AlterExtensionContentsStmt *stmt,
 
 	return extension;
 }
+
+/*
+ * Read the whole of file into memory.
+ *
+ * The file contents are returned as a single palloc'd chunk. For convenience
+ * of the callers, an extra \0 byte is added to the end.
+ */
+static char *
+read_whole_file(const char *filename, int *length)
+{
+	char	   *buf;
+	FILE	   *file;
+	size_t		bytes_to_read;
+	struct stat fst;
+
+	if (stat(filename, &fst) < 0)
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not stat file \"%s\": %m", filename)));
+
+	if (fst.st_size > (MaxAllocSize - 1))
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("file too large")));
+	bytes_to_read = (size_t) fst.st_size;
+
+	if ((file = AllocateFile(filename, PG_BINARY_R)) == NULL)
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not open file \"%s\" for reading: %m",
+						filename)));
+
+	buf = (char *) palloc(bytes_to_read + 1);
+
+	*length = fread(buf, 1, bytes_to_read, file);
+
+	if (ferror(file))
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not read file \"%s\": %m", filename)));
+
+	FreeFile(file);
+
+	buf[*length] = '\0';
+	return buf;
+}
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index f3f3cca515..c4eb10d3cf 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -35,6 +35,7 @@ typedef struct
 {
 	char	   *location;
 	DIR		   *dirdesc;
+	bool		include_dot_dirs;
 } directory_fctx;
 
 
@@ -87,8 +88,9 @@ convert_and_check_filename(text *arg)
  *
  * We read the whole of the file when bytes_to_read is negative.
  */
-bytea *
-read_binary_file(const char *filename, int64 seek_offset, int64 bytes_to_read)
+static bytea *
+read_binary_file(const char *filename, int64 seek_offset, int64 bytes_to_read,
+				 bool missing_ok)
 {
 	bytea	   *buf;
 	size_t		nbytes;
@@ -103,9 +105,14 @@ read_binary_file(const char *filename, int64 seek_offset, int64 bytes_to_read)
 			struct stat fst;
 
 			if (stat(filename, &fst) < 0)
-				ereport(ERROR,
-						(errcode_for_file_access(),
-						 errmsg("could not stat file \"%s\": %m", filename)));
+			{
+				if (missing_ok && errno == ENOENT)
+					return NULL;
+				else
+					ereport(ERROR,
+							(errcode_for_file_access(),
+						errmsg("could not stat file \"%s\": %m", filename)));
+			}
 
 			bytes_to_read = fst.st_size - seek_offset;
 		}
@@ -118,10 +125,15 @@ read_binary_file(const char *filename, int64 seek_offset, int64 bytes_to_read)
 				 errmsg("requested length too large")));
 
 	if ((file = AllocateFile(filename, PG_BINARY_R)) == NULL)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\" for reading: %m",
-						filename)));
+	{
+		if (missing_ok && errno == ENOENT)
+			return NULL;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\" for reading: %m",
+							filename)));
+	}
 
 	if (fseeko(file, (off_t) seek_offset,
 			   (seek_offset >= 0) ? SEEK_SET : SEEK_END) != 0)
@@ -150,17 +162,23 @@ read_binary_file(const char *filename, int64 seek_offset, int64 bytes_to_read)
  * in the database encoding.
  */
 static text *
-read_text_file(const char *filename, int64 seek_offset, int64 bytes_to_read)
+read_text_file(const char *filename, int64 seek_offset, int64 bytes_to_read,
+			   bool missing_ok)
 {
 	bytea	   *buf;
 
-	buf = read_binary_file(filename, seek_offset, bytes_to_read);
+	buf = read_binary_file(filename, seek_offset, bytes_to_read, missing_ok);
 
-	/* Make sure the input is valid */
-	pg_verifymbstr(VARDATA(buf), VARSIZE(buf) - VARHDRSZ, false);
+	if (buf != NULL)
+	{
+		/* Make sure the input is valid */
+		pg_verifymbstr(VARDATA(buf), VARSIZE(buf) - VARHDRSZ, false);
 
-	/* OK, we can cast it to text safely */
-	return (text *) buf;
+		/* OK, we can cast it to text safely */
+		return (text *) buf;
+	}
+	else
+		return NULL;
 }
 
 /*
@@ -170,42 +188,38 @@ Datum
 pg_read_file(PG_FUNCTION_ARGS)
 {
 	text	   *filename_t = PG_GETARG_TEXT_P(0);
-	int64		seek_offset = PG_GETARG_INT64(1);
-	int64		bytes_to_read = PG_GETARG_INT64(2);
+	int64		seek_offset = 0;
+	int64		bytes_to_read = -1;
+	bool		missing_ok = false;
 	char	   *filename;
+	text	   *result;
 
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 (errmsg("must be superuser to read files"))));
 
-	filename = convert_and_check_filename(filename_t);
+	/* handle optional arguments */
+	if (PG_NARGS() >= 3)
+	{
+		seek_offset = PG_GETARG_INT64(1);
+		bytes_to_read = PG_GETARG_INT64(2);
 
-	if (bytes_to_read < 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("requested length cannot be negative")));
-
-	PG_RETURN_TEXT_P(read_text_file(filename, seek_offset, bytes_to_read));
-}
-
-/*
- * Read the whole of a file, returning it as text
- */
-Datum
-pg_read_file_all(PG_FUNCTION_ARGS)
-{
-	text	   *filename_t = PG_GETARG_TEXT_P(0);
-	char	   *filename;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to read files"))));
+		if (bytes_to_read < 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("requested length cannot be negative")));
+	}
+	if (PG_NARGS() >= 4)
+		missing_ok = PG_GETARG_BOOL(3);
 
 	filename = convert_and_check_filename(filename_t);
 
-	PG_RETURN_TEXT_P(read_text_file(filename, 0, -1));
+	result = read_text_file(filename, seek_offset, bytes_to_read, missing_ok);
+	if (result)
+		PG_RETURN_TEXT_P(result);
+	else
+		PG_RETURN_NULL();
 }
 
 /*
@@ -215,42 +229,72 @@ Datum
 pg_read_binary_file(PG_FUNCTION_ARGS)
 {
 	text	   *filename_t = PG_GETARG_TEXT_P(0);
-	int64		seek_offset = PG_GETARG_INT64(1);
-	int64		bytes_to_read = PG_GETARG_INT64(2);
+	int64		seek_offset = 0;
+	int64		bytes_to_read = -1;
+	bool		missing_ok = false;
 	char	   *filename;
+	bytea	   *result;
 
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 (errmsg("must be superuser to read files"))));
 
+	/* handle optional arguments */
+	if (PG_NARGS() >= 3)
+	{
+		seek_offset = PG_GETARG_INT64(1);
+		bytes_to_read = PG_GETARG_INT64(2);
+
+		if (bytes_to_read < 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("requested length cannot be negative")));
+	}
+	if (PG_NARGS() >= 4)
+		missing_ok = PG_GETARG_BOOL(3);
+
 	filename = convert_and_check_filename(filename_t);
 
-	if (bytes_to_read < 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("requested length cannot be negative")));
-
-	PG_RETURN_BYTEA_P(read_binary_file(filename, seek_offset, bytes_to_read));
+	result = read_binary_file(filename, seek_offset,
+							  bytes_to_read, missing_ok);
+	if (result)
+		PG_RETURN_BYTEA_P(result);
+	else
+		PG_RETURN_NULL();
 }
 
+
 /*
- * Read the whole of a file, returning it as bytea
+ * Wrapper functions for the 1 and 3 argument variants of pg_read_file()
+ * and pg_binary_read_file().
+ *
+ * These are necessary to pass the sanity check in opr_sanity, which checks
+ * that all built-in functions that share the implementing C function take
+ * the same number of arguments.
  */
+Datum
+pg_read_file_off_len(PG_FUNCTION_ARGS)
+{
+	return pg_read_file(fcinfo);
+}
+
+Datum
+pg_read_file_all(PG_FUNCTION_ARGS)
+{
+	return pg_read_file(fcinfo);
+}
+
+Datum
+pg_read_binary_file_off_len(PG_FUNCTION_ARGS)
+{
+	return pg_read_binary_file(fcinfo);
+}
+
 Datum
 pg_read_binary_file_all(PG_FUNCTION_ARGS)
 {
-	text	   *filename_t = PG_GETARG_TEXT_P(0);
-	char	   *filename;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to read files"))));
-
-	filename = convert_and_check_filename(filename_t);
-
-	PG_RETURN_BYTEA_P(read_binary_file(filename, 0, -1));
+	return pg_read_binary_file(fcinfo);
 }
 
 /*
@@ -266,18 +310,28 @@ pg_stat_file(PG_FUNCTION_ARGS)
 	bool		isnull[6];
 	HeapTuple	tuple;
 	TupleDesc	tupdesc;
+	bool		missing_ok = false;
 
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 (errmsg("must be superuser to get file information"))));
 
+	/* check the optional argument */
+	if (PG_NARGS() == 2)
+		missing_ok = PG_GETARG_BOOL(1);
+
 	filename = convert_and_check_filename(filename_t);
 
 	if (stat(filename, &fst) < 0)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not stat file \"%s\": %m", filename)));
+	{
+		if (missing_ok && errno == ENOENT)
+			PG_RETURN_NULL();
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not stat file \"%s\": %m", filename)));
+	}
 
 	/*
 	 * This record type had better match the output parameters declared for me
@@ -320,6 +374,18 @@ pg_stat_file(PG_FUNCTION_ARGS)
 	PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
 }
 
+/*
+ * stat a file (1 argument version)
+ *
+ * note: this wrapper is necessary to pass the sanity check in opr_sanity,
+ * which checks that all built-in functions that share the implementing C
+ * function take the same number of arguments
+ */
+Datum
+pg_stat_file_1arg(PG_FUNCTION_ARGS)
+{
+	return pg_stat_file(fcinfo);
+}
 
 /*
  * List a directory (returns the filenames only)
@@ -330,6 +396,7 @@ pg_ls_dir(PG_FUNCTION_ARGS)
 	FuncCallContext *funcctx;
 	struct dirent *de;
 	directory_fctx *fctx;
+	MemoryContext oldcontext;
 
 	if (!superuser())
 		ereport(ERROR,
@@ -338,7 +405,17 @@ pg_ls_dir(PG_FUNCTION_ARGS)
 
 	if (SRF_IS_FIRSTCALL())
 	{
-		MemoryContext oldcontext;
+		bool		missing_ok = false;
+		bool		include_dot_dirs = false;
+
+		/* check the optional arguments */
+		if (PG_NARGS() == 3)
+		{
+			if (!PG_ARGISNULL(1))
+				missing_ok = PG_GETARG_BOOL(1);
+			if (!PG_ARGISNULL(2))
+				include_dot_dirs = PG_GETARG_BOOL(2);
+		}
 
 		funcctx = SRF_FIRSTCALL_INIT();
 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
@@ -346,14 +423,22 @@ pg_ls_dir(PG_FUNCTION_ARGS)
 		fctx = palloc(sizeof(directory_fctx));
 		fctx->location = convert_and_check_filename(PG_GETARG_TEXT_P(0));
 
+		fctx->include_dot_dirs = include_dot_dirs;
 		fctx->dirdesc = AllocateDir(fctx->location);
 
 		if (!fctx->dirdesc)
-			ereport(ERROR,
-					(errcode_for_file_access(),
-					 errmsg("could not open directory \"%s\": %m",
-							fctx->location)));
-
+		{
+			if (missing_ok && errno == ENOENT)
+			{
+				MemoryContextSwitchTo(oldcontext);
+				SRF_RETURN_DONE(funcctx);
+			}
+			else
+				ereport(ERROR,
+						(errcode_for_file_access(),
+						 errmsg("could not open directory \"%s\": %m",
+								fctx->location)));
+		}
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -363,8 +448,9 @@ pg_ls_dir(PG_FUNCTION_ARGS)
 
 	while ((de = ReadDir(fctx->dirdesc, fctx->location)) != NULL)
 	{
-		if (strcmp(de->d_name, ".") == 0 ||
-			strcmp(de->d_name, "..") == 0)
+		if (!fctx->include_dot_dirs &&
+			(strcmp(de->d_name, ".") == 0 ||
+			 strcmp(de->d_name, "..") == 0))
 			continue;
 
 		SRF_RETURN_NEXT(funcctx, CStringGetTextDatum(de->d_name));
@@ -374,3 +460,16 @@ pg_ls_dir(PG_FUNCTION_ARGS)
 
 	SRF_RETURN_DONE(funcctx);
 }
+
+/*
+ * List a directory (1 argument version)
+ *
+ * note: this wrapper is necessary to pass the sanity check in opr_sanity,
+ * which checks that all built-in functions that share the implementing C
+ * function take the same number of arguments.
+ */
+Datum
+pg_ls_dir_1arg(PG_FUNCTION_ARGS)
+{
+	return pg_ls_dir(fcinfo);
+}
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index de9018b957..3515b6436a 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201506111
+#define CATALOG_VERSION_NO	201506281
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 6b3d1949ef..d1cc8907d7 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -3181,17 +3181,25 @@ DESCR("reload configuration files");
 DATA(insert OID = 2622 ( pg_rotate_logfile		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ _null_ pg_rotate_logfile _null_ _null_ _null_ ));
 DESCR("rotate log file");
 
-DATA(insert OID = 2623 ( pg_stat_file		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 2249 "25" "{25,20,1184,1184,1184,1184,16}" "{i,o,o,o,o,o,o}" "{filename,size,access,modification,change,creation,isdir}" _null_ _null_ pg_stat_file _null_ _null_ _null_ ));
+DATA(insert OID = 2623 ( pg_stat_file		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 2249 "25" "{25,20,1184,1184,1184,1184,16}" "{i,o,o,o,o,o,o}" "{filename,size,access,modification,change,creation,isdir}" _null_ _null_ pg_stat_file_1arg _null_ _null_ _null_ ));
 DESCR("get information about file");
-DATA(insert OID = 2624 ( pg_read_file		PGNSP PGUID 12 1 0 0 0 f f f f t f v 3 0 25 "25 20 20" _null_ _null_ _null_ _null_ _null_ pg_read_file _null_ _null_ _null_ ));
+DATA(insert OID = 3307 ( pg_stat_file		PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 2249 "25 16" "{25,16,20,1184,1184,1184,1184,16}" "{i,i,o,o,o,o,o,o}" "{filename,if_not_exists,size,access,modification,change,creation,isdir}" _null_ _null_ pg_stat_file _null_ _null_ _null_ ));
+DESCR("get information about file");
+DATA(insert OID = 2624 ( pg_read_file		PGNSP PGUID 12 1 0 0 0 f f f f t f v 3 0 25 "25 20 20" _null_ _null_ _null_ _null_ _null_ pg_read_file_off_len _null_ _null_ _null_ ));
+DESCR("read text from a file");
+DATA(insert OID = 3293 ( pg_read_file		PGNSP PGUID 12 1 0 0 0 f f f f t f v 4 0 25 "25 20 20 16" _null_ _null_ _null_ _null_ _null_ pg_read_file _null_ _null_ _null_ ));
 DESCR("read text from a file");
 DATA(insert OID = 3826 ( pg_read_file		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 25 "25" _null_ _null_ _null_ _null_ _null_ pg_read_file_all _null_ _null_ _null_ ));
 DESCR("read text from a file");
-DATA(insert OID = 3827 ( pg_read_binary_file	PGNSP PGUID 12 1 0 0 0 f f f f t f v 3 0 17 "25 20 20" _null_ _null_ _null_ _null_ _null_ pg_read_binary_file _null_ _null_ _null_ ));
+DATA(insert OID = 3827 ( pg_read_binary_file	PGNSP PGUID 12 1 0 0 0 f f f f t f v 3 0 17 "25 20 20" _null_ _null_ _null_ _null_ _null_ pg_read_binary_file_off_len _null_ _null_ _null_ ));
+DESCR("read bytea from a file");
+DATA(insert OID = 3295 ( pg_read_binary_file	PGNSP PGUID 12 1 0 0 0 f f f f t f v 4 0 17 "25 20 20 16" _null_ _null_ _null_ _null_ _null_ pg_read_binary_file _null_ _null_ _null_ ));
 DESCR("read bytea from a file");
 DATA(insert OID = 3828 ( pg_read_binary_file	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 17 "25" _null_ _null_ _null_ _null_ _null_ pg_read_binary_file_all _null_ _null_ _null_ ));
 DESCR("read bytea from a file");
-DATA(insert OID = 2625 ( pg_ls_dir			PGNSP PGUID 12 1 1000 0 0 f f f f t t v 1 0 25 "25" _null_ _null_ _null_ _null_ _null_ pg_ls_dir _null_ _null_ _null_ ));
+DATA(insert OID = 2625 ( pg_ls_dir			PGNSP PGUID 12 1 1000 0 0 f f f f t t v 1 0 25 "25" _null_ _null_ _null_ _null_ _null_ pg_ls_dir_1arg _null_ _null_ _null_ ));
+DESCR("list all files in a directory");
+DATA(insert OID = 3297 ( pg_ls_dir			PGNSP PGUID 12 1 1000 0 0 f f f f t t v 3 0 25 "25 16 16" _null_ _null_ _null_ _null_ _null_ pg_ls_dir _null_ _null_ _null_ ));
 DESCR("list all files in a directory");
 DATA(insert OID = 2626 ( pg_sleep			PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 2278 "701" _null_ _null_ _null_ _null_ _null_ pg_sleep _null_ _null_ _null_ ));
 DESCR("sleep for the specified time in seconds");
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 51f25a2814..98556725c8 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -469,14 +469,16 @@ extern Datum pg_filenode_relation(PG_FUNCTION_ARGS);
 extern Datum pg_relation_filepath(PG_FUNCTION_ARGS);
 
 /* genfile.c */
-extern bytea *read_binary_file(const char *filename,
-				 int64 seek_offset, int64 bytes_to_read);
 extern Datum pg_stat_file(PG_FUNCTION_ARGS);
+extern Datum pg_stat_file_1arg(PG_FUNCTION_ARGS);
 extern Datum pg_read_file(PG_FUNCTION_ARGS);
+extern Datum pg_read_file_off_len(PG_FUNCTION_ARGS);
 extern Datum pg_read_file_all(PG_FUNCTION_ARGS);
 extern Datum pg_read_binary_file(PG_FUNCTION_ARGS);
+extern Datum pg_read_binary_file_off_len(PG_FUNCTION_ARGS);
 extern Datum pg_read_binary_file_all(PG_FUNCTION_ARGS);
 extern Datum pg_ls_dir(PG_FUNCTION_ARGS);
+extern Datum pg_ls_dir_1arg(PG_FUNCTION_ARGS);
 
 /* misc.c */
 extern Datum current_database(PG_FUNCTION_ARGS);