Index: config.h.in
==================================================================
--- config.h.in
+++ config.h.in
@@ -42,10 +42,22 @@
 /* Define to 1 if you have the `malloc_usable_size' function. */
 #undef HAVE_MALLOC_USABLE_SIZE
 
 /* Define to 1 if you have the <memory.h> header file. */
 #undef HAVE_MEMORY_H
+
+/* Define to 1 if you have the pread() function. */
+#undef HAVE_PREAD
+
+/* Define to 1 if you have the pread64() function. */
+#undef HAVE_PREAD64
+
+/* Define to 1 if you have the pwrite() function. */
+#undef HAVE_PWRITE
+
+/* Define to 1 if you have the pwrite64() function. */
+#undef HAVE_PWRITE64
 
 /* Define to 1 if you have the <stdint.h> header file. */
 #undef HAVE_STDINT_H
 
 /* Define to 1 if you have the <stdlib.h> header file. */

Index: configure
==================================================================
--- configure
+++ configure
@@ -10271,11 +10271,11 @@
 
 
 #########
 # Figure out whether or not we have these functions
 #
-for ac_func in fdatasync gmtime_r isnan localtime_r localtime_s malloc_usable_size strchrnul usleep utime
+for ac_func in fdatasync gmtime_r isnan localtime_r localtime_s malloc_usable_size strchrnul usleep utime pread pread64 pwrite pwrite64
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
 if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
   cat >>confdefs.h <<_ACEOF

Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -106,11 +106,11 @@
 AC_CHECK_HEADERS([sys/types.h stdlib.h stdint.h inttypes.h malloc.h])
 
 #########
 # Figure out whether or not we have these functions
 #
-AC_CHECK_FUNCS([fdatasync gmtime_r isnan localtime_r localtime_s malloc_usable_size strchrnul usleep utime])
+AC_CHECK_FUNCS([fdatasync gmtime_r isnan localtime_r localtime_s malloc_usable_size strchrnul usleep utime pread pread64 pwrite pwrite64])
 
 #########
 # By default, we use the amalgamation (this may be changed below...)
 #
 USE_AMALGAMATION=1

Index: src/os_unix.c
==================================================================
--- src/os_unix.c
+++ src/os_unix.c
@@ -68,10 +68,23 @@
 #    define SQLITE_ENABLE_LOCKING_STYLE 1
 #  else
 #    define SQLITE_ENABLE_LOCKING_STYLE 0
 #  endif
 #endif
+
+/* Use pread() and pwrite() if they are available */
+#if defined(__APPLE__)
+# define HAVE_PREAD 1
+# define HAVE_PWRITE 1
+#endif
+#if defined(HAVE_PREAD64) && defined(HAVE_PWRITE64)
+# undef USE_PREAD
+# define USE_PREAD64 1
+#elif defined(HAVE_PREAD) && defined(HAVE_PWRITE)
+# undef USE_PREAD64
+# define USE_PREAD 1
+#endif
 
 /*
 ** standard include files.
 */
 #include <sys/types.h>