De-support floating-point timestamps.

Per discussion, the time has come to do this.  The handwriting has been
on the wall at least since 9.0 that this would happen someday, whenever
it got to be too much of a burden to support the float-timestamp option.
The triggering factor now is the discovery that there are multiple bugs
in the code that attempts to implement use of integer timestamps in the
replication protocol even when the server is built for float timestamps.
The internal float timestamps leak into the protocol fields in places.
While we could fix the identified bugs, there's a very high risk of
introducing more.  Trying to build a wall that would positively prevent
mixing integer and float timestamps is more complexity than we want to
undertake to maintain a long-deprecated option.  The fact that these
bugs weren't found through testing also indicates a lack of interest
in float timestamps.

This commit disables configure's --disable-integer-datetimes switch
(it'll still accept --enable-integer-datetimes, though), removes direct
references to USE_INTEGER_DATETIMES, and removes discussion of float
timestamps from the user documentation.  A considerable amount of code is
rendered dead by this, but removing that will occur as separate mop-up.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us

10 files changed, 10 insertions, 35 deletions

diff --git a/src/include/c.h b/src/include/c.h
index 91e5baa9692..947bd980672 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -340,10 +340,11 @@ typedef unsigned PG_INT128_TYPE uint128;
 #define PG_INT64_MAX	INT64CONST(0x7FFFFFFFFFFFFFFF)
 #define PG_UINT64_MAX	UINT64CONST(0xFFFFFFFFFFFFFFFF)
 
-/* Select timestamp representation (float8 or int64) */
-#ifdef USE_INTEGER_DATETIMES
+/*
+ * We now always use int64 timestamps, but keep this symbol defined for the
+ * benefit of external code that might test it.
+ */
 #define HAVE_INT64_TIMESTAMP
-#endif
 
 /*
  * Size
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index b9dfdd41c1a..8dd73f1d915 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -831,10 +831,6 @@
    (--enable-float8-byval) */
 #undef USE_FLOAT8_BYVAL
 
-/* Define to 1 if you want 64-bit integer timestamp and interval support.
-   (--enable-integer-datetimes) */
-#undef USE_INTEGER_DATETIMES
-
 /* Define to 1 to build with LDAP support. (--with-ldap) */
 #undef USE_LDAP
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 199668c1876..fd1af59839d 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -625,10 +625,6 @@
 /* Define to use /dev/urandom for random number generation */
 /* #undef USE_DEV_URANDOM */
 
-/* Define to 1 if you want 64-bit integer timestamp and interval support.
-   (--enable-integer-datetimes) */
-/* #undef USE_INTEGER_DATETIMES */
-
 /* Define to 1 to build with LDAP support. (--with-ldap) */
 /* #undef USE_LDAP */
 
diff --git a/src/interfaces/ecpg/include/ecpg_config.h.in b/src/interfaces/ecpg/include/ecpg_config.h.in
index bf99a5e7930..736fb08dba3 100644
--- a/src/interfaces/ecpg/include/ecpg_config.h.in
+++ b/src/interfaces/ecpg/include/ecpg_config.h.in
@@ -10,10 +10,6 @@
 /* Define to 1 if `long long int' works and is 64 bits. */
 #undef HAVE_LONG_LONG_INT_64
 
-/* Define to 1 if you want 64-bit integer timestamp and interval support.
-   (--enable-integer-datetimes) */
-#undef USE_INTEGER_DATETIMES
-
 /* Define to 1 to build client libraries as thread-safe code.
  *    (--enable-thread-safety) */
 #undef ENABLE_THREAD_SAFETY
diff --git a/src/interfaces/ecpg/include/pgtypes_interval.h b/src/interfaces/ecpg/include/pgtypes_interval.h
index deac6a2e01a..5118ec784d1 100644
--- a/src/interfaces/ecpg/include/pgtypes_interval.h
+++ b/src/interfaces/ecpg/include/pgtypes_interval.h
@@ -20,9 +20,7 @@ typedef long long int int64;
 #error must have a working 64-bit integer datatype
 #endif
 
-#ifdef USE_INTEGER_DATETIMES
 #define HAVE_INT64_TIMESTAMP
-#endif
 #endif   /* C_H */
 
 typedef struct
diff --git a/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.c b/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.c
index 4277c2615da..b6e77562b24 100644
--- a/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.c
+++ b/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.c
@@ -145,10 +145,8 @@ main(void)
 				sprintf(t, "%s %s", dates[i], times[j]);
 				ts1 = PGTYPEStimestamp_from_asc(t, NULL);
 				text = PGTYPEStimestamp_to_asc(ts1);
-				/* skip outputs sensitive to USE_INTEGER_DATETIMES */
-				if (i != 19 || (j != 3 && j != 4))
-					printf("TS[%d,%d]: %s\n",
-						i, j, errno ? "-" : text);
+				printf("TS[%d,%d]: %s\n",
+				       i, j, errno ? "-" : text);
 				free(text);
 				free(t);
 			}
diff --git a/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.stdout b/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.stdout
index 941bffbd815..0fbcce67b68 100644
--- a/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.stdout
+++ b/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.stdout
@@ -103,6 +103,8 @@ Date[19]: 0099-01-08 BC (N - F)
 TS[19,0]: 0099-01-08 00:04:00 BC
 TS[19,1]: 0099-01-08 01:59:00 BC
 TS[19,2]: 0099-01-08 13:24:40 BC
+TS[19,3]: 0099-01-08 13:24:40.495 BC
+TS[19,4]: 0099-01-08 13:24:40.123456 BC
 Date[20]: - (N - T)
 Date[21]: - (N - T)
 interval[0]: @ 1 min
diff --git a/src/interfaces/ecpg/test/pgtypeslib/dt_test2.pgc b/src/interfaces/ecpg/test/pgtypeslib/dt_test2.pgc
index 0bd1fec109d..d519305e188 100644
--- a/src/interfaces/ecpg/test/pgtypeslib/dt_test2.pgc
+++ b/src/interfaces/ecpg/test/pgtypeslib/dt_test2.pgc
@@ -110,10 +110,8 @@ main(void)
 				sprintf(t, "%s %s", dates[i], times[j]);
 				ts1 = PGTYPEStimestamp_from_asc(t, NULL);
 				text = PGTYPEStimestamp_to_asc(ts1);
-				/* skip outputs sensitive to USE_INTEGER_DATETIMES */
-				if (i != 19 || (j != 3 && j != 4))
-					printf("TS[%d,%d]: %s\n",
-						i, j, errno ? "-" : text);
+				printf("TS[%d,%d]: %s\n",
+				       i, j, errno ? "-" : text);
 				free(text);
 				free(t);
 			}
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index fbf4da3d68f..ff9064f923d 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -28,9 +28,6 @@ sub _new
 	$self->DeterminePlatform();
 	my $bits = $self->{platform} eq 'Win32' ? 32 : 64;
 
-	# integer_datetimes is now the default
-	$options->{integer_datetimes} = 1
-	  unless exists $options->{integer_datetimes};
 	$options->{float4byval} = 1
 	  unless exists $options->{float4byval};
 	$options->{float8byval} = ($bits == 64)
@@ -169,8 +166,6 @@ s{PG_VERSION_STR "[^"]+"}{__STRINGIFY(x) #x\n#define __STRINGIFY2(z) __STRINGIFY
 		print O "#ifndef IGNORE_CONFIGURED_SETTINGS\n";
 		print O "#define USE_ASSERT_CHECKING 1\n"
 		  if ($self->{options}->{asserts});
-		print O "#define USE_INTEGER_DATETIMES 1\n"
-		  if ($self->{options}->{integer_datetimes});
 		print O "#define USE_LDAP 1\n"    if ($self->{options}->{ldap});
 		print O "#define HAVE_LIBZ 1\n"   if ($self->{options}->{zlib});
 		print O "#define USE_OPENSSL 1\n" if ($self->{options}->{openssl});
@@ -427,8 +422,6 @@ s{PG_VERSION_STR "[^"]+"}{__STRINGIFY(x) #x\n#define __STRINGIFY2(z) __STRINGIFY
 #define HAVE_LONG_LONG_INT_64
 #define ENABLE_THREAD_SAFETY 1
 EOF
-		print O "#define USE_INTEGER_DATETIMES 1\n"
-		  if ($self->{options}->{integer_datetimes});
 		print O "#endif\n";
 		close(O);
 	}
@@ -661,8 +654,6 @@ sub GetFakeConfigure
 
 	my $cfg = '--enable-thread-safety';
 	$cfg .= ' --enable-cassert' if ($self->{options}->{asserts});
-	$cfg .= ' --enable-integer-datetimes'
-	  if ($self->{options}->{integer_datetimes});
 	$cfg .= ' --enable-nls'       if ($self->{options}->{nls});
 	$cfg .= ' --enable-tap-tests' if ($self->{options}->{tap_tests});
 	$cfg .= ' --with-ldap'        if ($self->{options}->{ldap});
diff --git a/src/tools/msvc/config_default.pl b/src/tools/msvc/config_default.pl
index f046687bd06..97f1af8b49e 100644
--- a/src/tools/msvc/config_default.pl
+++ b/src/tools/msvc/config_default.pl
@@ -4,7 +4,6 @@ use warnings;
 
 our $config = {
 	asserts => 0,    # --enable-cassert
-	  # integer_datetimes=>1,   # --enable-integer-datetimes - on is now default
 	  # float4byval=>1,         # --disable-float4-byval, on by default
 
 	# float8byval=> $platformbits == 64, # --disable-float8-byval,