diff --git a/configure b/configure
index c2fae1ee65d..3b96e266120 100755
--- a/configure
+++ b/configure
@@ -649,7 +649,6 @@ XGETTEXT
 MSGMERGE
 MSGFMT_FLAGS
 MSGFMT
-enable_largefile
 PG_CRC32C_OBJS
 CFLAGS_ARMV8_CRC32C
 CFLAGS_SSE42
@@ -21032,6 +21031,7 @@ $as_echo "#define HAVE_GCC__ATOMIC_INT64_CAS 1" >>confdefs.h
 
 fi
 
+
 # Check for x86 cpuid instruction
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __get_cpuid" >&5
 $as_echo_n "checking for __get_cpuid... " >&6; }
@@ -21388,255 +21388,6 @@ fi
 
 
 
-if test $ac_cv_func_fseeko = yes; then
-# Check whether --enable-largefile was given.
-if test "${enable_largefile+set}" = set; then :
-  enableval=$enable_largefile;
-fi
-
-if test "$enable_largefile" != no; then
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for special C compiler options needed for large files" >&5
-$as_echo_n "checking for special C compiler options needed for large files... " >&6; }
-if ${ac_cv_sys_largefile_CC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_cv_sys_largefile_CC=no
-     if test "$GCC" != yes; then
-       ac_save_CC=$CC
-       while :; do
-	 # IRIX 6.2 and later do not support large files by default,
-	 # so use the C compiler's -n32 option if that helps.
-	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <sys/types.h>
- /* Check that off_t can represent 2**63 - 1 correctly.
-    We can't simply define LARGE_OFF_T to be 9223372036854775807,
-    since some C++ compilers masquerading as C compilers
-    incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
-  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
-		       && LARGE_OFF_T % 2147483647 == 1)
-		      ? 1 : -1];
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-	 if ac_fn_c_try_compile "$LINENO"; then :
-  break
-fi
-rm -f core conftest.err conftest.$ac_objext
-	 CC="$CC -n32"
-	 if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_sys_largefile_CC=' -n32'; break
-fi
-rm -f core conftest.err conftest.$ac_objext
-	 break
-       done
-       CC=$ac_save_CC
-       rm -f conftest.$ac_ext
-    fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_largefile_CC" >&5
-$as_echo "$ac_cv_sys_largefile_CC" >&6; }
-  if test "$ac_cv_sys_largefile_CC" != no; then
-    CC=$CC$ac_cv_sys_largefile_CC
-  fi
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for _FILE_OFFSET_BITS value needed for large files" >&5
-$as_echo_n "checking for _FILE_OFFSET_BITS value needed for large files... " >&6; }
-if ${ac_cv_sys_file_offset_bits+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  while :; do
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <sys/types.h>
- /* Check that off_t can represent 2**63 - 1 correctly.
-    We can't simply define LARGE_OFF_T to be 9223372036854775807,
-    since some C++ compilers masquerading as C compilers
-    incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
-  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
-		       && LARGE_OFF_T % 2147483647 == 1)
-		      ? 1 : -1];
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_sys_file_offset_bits=no; break
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#define _FILE_OFFSET_BITS 64
-#include <sys/types.h>
- /* Check that off_t can represent 2**63 - 1 correctly.
-    We can't simply define LARGE_OFF_T to be 9223372036854775807,
-    since some C++ compilers masquerading as C compilers
-    incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
-  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
-		       && LARGE_OFF_T % 2147483647 == 1)
-		      ? 1 : -1];
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_sys_file_offset_bits=64; break
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-  ac_cv_sys_file_offset_bits=unknown
-  break
-done
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_file_offset_bits" >&5
-$as_echo "$ac_cv_sys_file_offset_bits" >&6; }
-case $ac_cv_sys_file_offset_bits in #(
-  no | unknown) ;;
-  *)
-cat >>confdefs.h <<_ACEOF
-#define _FILE_OFFSET_BITS $ac_cv_sys_file_offset_bits
-_ACEOF
-;;
-esac
-rm -rf conftest*
-  if test $ac_cv_sys_file_offset_bits = unknown; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for _LARGE_FILES value needed for large files" >&5
-$as_echo_n "checking for _LARGE_FILES value needed for large files... " >&6; }
-if ${ac_cv_sys_large_files+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  while :; do
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <sys/types.h>
- /* Check that off_t can represent 2**63 - 1 correctly.
-    We can't simply define LARGE_OFF_T to be 9223372036854775807,
-    since some C++ compilers masquerading as C compilers
-    incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
-  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
-		       && LARGE_OFF_T % 2147483647 == 1)
-		      ? 1 : -1];
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_sys_large_files=no; break
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#define _LARGE_FILES 1
-#include <sys/types.h>
- /* Check that off_t can represent 2**63 - 1 correctly.
-    We can't simply define LARGE_OFF_T to be 9223372036854775807,
-    since some C++ compilers masquerading as C compilers
-    incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
-  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
-		       && LARGE_OFF_T % 2147483647 == 1)
-		      ? 1 : -1];
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_sys_large_files=1; break
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-  ac_cv_sys_large_files=unknown
-  break
-done
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_large_files" >&5
-$as_echo "$ac_cv_sys_large_files" >&6; }
-case $ac_cv_sys_large_files in #(
-  no | unknown) ;;
-  *)
-cat >>confdefs.h <<_ACEOF
-#define _LARGE_FILES $ac_cv_sys_large_files
-_ACEOF
-;;
-esac
-rm -rf conftest*
-  fi
-
-
-fi
-
-enable_largefile=yes
-else
-enable_largefile=no
-fi
-
-
-# Check for largefile support (must be after AC_SYS_LARGEFILE)
-# The cast to long int works around a bug in the HP C Compiler
-# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
-# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
-# This bug is HP SR number 8606223364.
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking size of off_t" >&5
-$as_echo_n "checking size of off_t... " >&6; }
-if ${ac_cv_sizeof_off_t+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (off_t))" "ac_cv_sizeof_off_t"        "$ac_includes_default"; then :
-
-else
-  if test "$ac_cv_type_off_t" = yes; then
-     { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error 77 "cannot compute sizeof (off_t)
-See \`config.log' for more details" "$LINENO" 5; }
-   else
-     ac_cv_sizeof_off_t=0
-   fi
-fi
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_off_t" >&5
-$as_echo "$ac_cv_sizeof_off_t" >&6; }
-
-
-
-cat >>confdefs.h <<_ACEOF
-#define SIZEOF_OFF_T $ac_cv_sizeof_off_t
-_ACEOF
-
-
-
-if test "$PORTNAME" != "win32"; then
-# If we don't have largefile support, can't handle segsize >= 2GB.
-if test "$ac_cv_sizeof_off_t" -lt 8 -a "$segsize" != "1"; then
-   as_fn_error $? "Large file support is not enabled. Segment size cannot be larger than 1GB." "$LINENO" 5
-fi
-fi
-
 # Select semaphore implementation type.
 if test "$PORTNAME" != "win32"; then
   if test x"$PREFERRED_SEMAPHORES" = x"NAMED_POSIX" ; then
diff --git a/configure.ac b/configure.ac
index 47d953de3de..71e5e3c9c2a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2734,24 +2734,6 @@ fi
 AC_SUBST(PG_CRC32C_OBJS)
 
 
-if test $ac_cv_func_fseeko = yes; then
-AC_SYS_LARGEFILE
-enable_largefile=yes
-else
-enable_largefile=no
-fi
-AC_SUBST(enable_largefile)
-
-# Check for largefile support (must be after AC_SYS_LARGEFILE)
-AC_CHECK_SIZEOF([off_t])
-
-if test "$PORTNAME" != "win32"; then
-# If we don't have largefile support, can't handle segsize >= 2GB.
-if test "$ac_cv_sizeof_off_t" -lt 8 -a "$segsize" != "1"; then
-   AC_MSG_ERROR([Large file support is not enabled. Segment size cannot be larger than 1GB.])
-fi
-fi
-
 # Select semaphore implementation type.
 if test "$PORTNAME" != "win32"; then
   if test x"$PREFERRED_SEMAPHORES" = x"NAMED_POSIX" ; then