Add extra_float_digits GUC parameter to allow adjustment of displayed

precision for float4, float8, and geometric types.  Set it in pg_dump
so that float data can be dumped/reloaded exactly (at least on platforms
where the float I/O support is properly implemented).  Initial patch by
Pedro Ferreira, some additional work by Tom Lane.

src/backend/utils/misc/guc.c

@@ -5,7 +5,7 @@
  * command, configuration file, and command line options.
  * See src/backend/utils/misc/README for more information.
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.99 2002/11/01 22:52:33 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.100 2002/11/08 17:37:52 tgl Exp $
  *
  * Copyright 2000 by PostgreSQL Global Development Group
  * Written by Peter Eisentraut <peter_e@gmx.net>.
@@ -680,6 +680,11 @@ static struct config_int
 		5, 1, 1000, NULL, NULL
 	},
 
+	{
+		{"extra_float_digits", PGC_USERSET}, &extra_float_digits,
+		0, -15, 2, NULL, NULL
+	},
+
 	{
 		{NULL, 0}, NULL, 0, 0, 0, NULL, NULL
 	}

src/backend/utils/misc/postgresql.conf.sample

@@ -127,7 +127,7 @@
 #log_duration = false
 #log_timestamp = false
 
-#log_min_error_statement = error		# Values in order of increasing severity:
+#log_min_error_statement = error	# Values in order of increasing severity:
 									# debug5, debug4, debug3, debug2, debug1,
 					                # info, notice, warning, error
 #debug_print_parse = false
@@ -198,6 +198,7 @@
 #authentication_timeout = 60	# 1-600, in seconds
 #deadlock_timeout = 1000	# in milliseconds
 #default_transaction_isolation = 'read committed'
+#extra_float_digits = 0		# min -15, max 2
 #max_expr_depth = 10000		# min 10
 #max_files_per_process = 1000	# min 25
 #password_encryption = true