Add --no-blobs option to pg_dump

Add an option to exclude blobs when running pg_dump.  By default, blobs
are included but this option can be used to exclude them while keeping
the rest of the dump.

Commment updates and regression tests from me.

Author: Guillaume Lelarge
Reviewed-by: Amul Sul
Discussion: https://postgr.es/m/VisenaEmail.48.49926ea6f91dceb6.15355a48249@tc7-visena

doc/src/sgml/ref/pg_dump.sgml

@@ -147,6 +147,22 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>-B</></term>
+      <term><option>--no-blobs</></term>
+      <listitem>
+       <para>
+        Exclude large objects in the dump.
+       </para>
+
+       <para>
+        When both <option>-b</> and <option>-B</> are given, the behavior
+        is to output large objects, when data is being dumped, see the
+        <option>-b</> documentation.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-c</option></term>
       <term><option>--clean</option></term>

src/bin/pg_dump/pg_backup.h

@@ -159,6 +159,7 @@ typedef struct _dumpOptions
 	int			outputClean;
 	int			outputCreateDB;
 	bool		outputBlobs;
+	bool		dontOutputBlobs;
 	int			outputNoOwner;
 	char	   *outputSuperuser;
 

src/bin/pg_dump/pg_dump.c

@@ -291,6 +291,7 @@ main(int argc, char **argv)
 	static struct option long_options[] = {
 		{"data-only", no_argument, NULL, 'a'},
 		{"blobs", no_argument, NULL, 'b'},
+		{"no-blobs", no_argument, NULL, 'B'},
 		{"clean", no_argument, NULL, 'c'},
 		{"create", no_argument, NULL, 'C'},
 		{"dbname", required_argument, NULL, 'd'},
@@ -379,7 +380,7 @@ main(int argc, char **argv)
 
 	InitDumpOptions(&dopt);
 
-	while ((c = getopt_long(argc, argv, "abcCd:E:f:F:h:j:n:N:oOp:RsS:t:T:U:vwWxZ:",
+	while ((c = getopt_long(argc, argv, "abBcCd:E:f:F:h:j:n:N:oOp:RsS:t:T:U:vwWxZ:",
 							long_options, &optindex)) != -1)
 	{
 		switch (c)
@@ -392,6 +393,10 @@ main(int argc, char **argv)
 				dopt.outputBlobs = true;
 				break;
 
+			case 'B':			/* Don't dump blobs */
+				dopt.dontOutputBlobs = true;
+				break;
+
 			case 'c':			/* clean (i.e., drop) schema prior to create */
 				dopt.outputClean = 1;
 				break;
@@ -713,10 +718,15 @@ main(int argc, char **argv)
 	/* non-matching exclusion patterns aren't an error */
 
 	/*
-	 * Dumping blobs is now default unless we saw an inclusion switch or -s
-	 * ... but even if we did see one of these, -b turns it back on.
+	 * Dumping blobs is the default for dumps where an inclusion switch is not
+	 * used (an "include everything" dump).  -B can be used to exclude blobs
+	 * from those dumps.  -b can be used to include blobs even when an
+	 * inclusion switch is used.
+	 *
+	 * -s means "schema only" and blobs are data, not schema, so we never
+	 * include blobs when -s is used.
 	 */
-	if (dopt.include_everything && !dopt.schemaOnly)
+	if (dopt.include_everything && !dopt.schemaOnly && !dopt.dontOutputBlobs)
 		dopt.outputBlobs = true;
 
 	/*
@@ -876,6 +886,7 @@ help(const char *progname)
 	printf(_("\nOptions controlling the output content:\n"));
 	printf(_("  -a, --data-only              dump only the data, not the schema\n"));
 	printf(_("  -b, --blobs                  include large objects in dump\n"));
+	printf(_("  -B, --no-blobs               exclude large objects in dump\n"));
 	printf(_("  -c, --clean                  clean (drop) database objects before recreating\n"));
 	printf(_("  -C, --create                 include commands to create database in dump\n"));
 	printf(_("  -E, --encoding=ENCODING      dump the data in encoding ENCODING\n"));