Adding pg_dump flag for parallel export to pipes

From 87dec759a665729971e162e17600207b3e2f5a22 Mon Sep 17 00:00:00 2001
From: Nitin Motiani <nitinmotiani@google.com>
Date: Sat, 15 Feb 2025 04:29:17 +0000
Subject: [PATCH v5 3/5] Add basic tests for pipe-command

* This currently only adds a few basic tests for pg_dump with --pipe-command.
* These tests include the invalid usages of --pipe-command with other flags.
* We are still working on adding other tests in pg_dump.pl. But
  we ran into some issues which might be related to setup.
---
 src/bin/pg_dump/t/001_basic.pl | 36 ++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/bin/pg_dump/t/001_basic.pl b/src/bin/pg_dump/t/001_basic.pl
index 84ca25e17d6..3badd335f8c 100644
--- a/src/bin/pg_dump/t/001_basic.pl
+++ b/src/bin/pg_dump/t/001_basic.pl
@@ -74,6 +74,42 @@ command_fails_like(
 	'pg_dump: options --statistics-only and --no-statistics cannot be used together'
 );
 
+command_fails_like(
+	[ 'pg_dump', '-Fd', '--pipe-command="cat"', '-f', 'testdir', 'test'],
+	qr/\Qpg_dump: hint: Only one of [--file, --pipe-command] allowed\E/,
+	'pg_dump: hint: Only one of [--file, --pipe-command] allowed'
+);
+
+command_fails_like(
+	[ 'pg_dump', '-Fd', '--pipe-command="cat"', '-Z', 'gzip', 'test'],
+	qr/\Qpg_dump: hint: Option --pipe-command is not supported with any compression type\E/,
+	'pg_dump: hint: Option --pipe-command is not supported with any compression type'
+);
+
+command_fails_like(
+	[ 'pg_dump', '-Fd', '--pipe-command="cat"', '--compress=lz4', 'test'],
+	qr/\Qpg_dump: hint: Option --pipe-command is not supported with any compression type\E/,
+	'pg_dump: hint: Option --pipe-command is not supported with any compression type'
+);
+
+command_fails_like(
+	[ 'pg_dump', '-Fd', '--pipe-command="cat"', '-Z', '1', 'test'],
+	qr/\Qpg_dump: hint: Option --pipe-command is not supported with any compression type\E/,
+	'pg_dump: hint: Option --pipe-command is not supported with any compression type'
+);
+
+command_fails_like(
+	[ 'pg_dump', '-Fc', '--pipe-command="cat"', 'test'],
+	qr/\Qpg_dump: hint: Option --pipe-command is only supported with directory format.\E/,
+	'pg_dump: hint: Option --pipe-command is only supported with directory format.'
+);
+
+command_fails_like(
+	[ 'pg_dump', '--format=tar', '--pipe-command="cat"', 'test'],
+	qr/\Qpg_dump: hint: Option --pipe-command is only supported with directory format.\E/,
+	'pg_dump: hint: Option --pipe-command is only supported with directory format.'
+);
+
 command_fails_like(
 	[ 'pg_dump', '-j2', '--include-foreign-data=xxx' ],
 	qr/\Qpg_dump: error: option --include-foreign-data is not supported with parallel backup\E/,
-- 
2.49.0.1266.g31b7d2e469-goog

From c543f4b20d79cce3bdc77f328a1fb0560c2cdfdb Mon Sep 17 00:00:00 2001
From: Nitin Motiani <nitinmotiani@google.com>
Date: Sat, 15 Feb 2025 08:05:25 +0000
Subject: [PATCH v5 2/5] Add pipe-command support in pg_restore

* This is same as the pg_dump change. We add support
  for --pipe-command in directory archive format. This can be used
  to read from multiple streams and do pre-processing (decompression
  with a custom algorithm, filtering etc) before restore.
  Currently that is not possible because the pg_dump output of
  directory format can't just be piped.
* Like pg_dump, here also either filename or --pipe-command can be
  set. If neither are set, the standard input is used as before.
* This is only supported with compression none and archive format
  directory.
* We reuse the inputFileSpec field for the pipe-command. And add
  a bool to specify if it is a pipe.
* The changes made for pg_dump to handle the pipe case with popen
  and pclose also work here.
* The logic of %f format specifier to read from the pg_dump output
  is the same too. Most of the code from the pg_dump commit works.
  We add similar logic to the function to read large objects.
* The --pipe command works -l and -L option.
---
 src/bin/pg_dump/compress_io.c         | 34 +++++++++++++----------
 src/bin/pg_dump/pg_backup_directory.c | 13 ++++++++-
 src/bin/pg_dump/pg_restore.c          | 39 ++++++++++++++++++++++-----
 3 files changed, 64 insertions(+), 22 deletions(-)

diff --git a/src/bin/pg_dump/compress_io.c b/src/bin/pg_dump/compress_io.c
index b3e1a133af8..7b151265165 100644
--- a/src/bin/pg_dump/compress_io.c
+++ b/src/bin/pg_dump/compress_io.c
@@ -259,26 +259,32 @@ InitDiscoverCompressFileHandle(const char *path, const char *mode,
 	Assert(strcmp(mode, PG_BINARY_R) == 0);
 
 	fname = pg_strdup(path);
-
-	if (hasSuffix(fname, ".gz"))
-		compression_spec.algorithm = PG_COMPRESSION_GZIP;
-	else if (hasSuffix(fname, ".lz4"))
-		compression_spec.algorithm = PG_COMPRESSION_LZ4;
-	else if (hasSuffix(fname, ".zst"))
-		compression_spec.algorithm = PG_COMPRESSION_ZSTD;
-	else
+	/*
+	   If the path is a pipe command, the compression algorithm
+	   is none.
+	*/
+	if (!path_is_pipe_command)
 	{
-		if (stat(path, &st) == 0)
-			compression_spec.algorithm = PG_COMPRESSION_NONE;
-		else if (check_compressed_file(path, &fname, "gz"))
+		if (hasSuffix(fname, ".gz"))
 			compression_spec.algorithm = PG_COMPRESSION_GZIP;
-		else if (check_compressed_file(path, &fname, "lz4"))
+		else if (hasSuffix(fname, ".lz4"))
 			compression_spec.algorithm = PG_COMPRESSION_LZ4;
-		else if (check_compressed_file(path, &fname, "zst"))
+		else if (hasSuffix(fname, ".zst"))
 			compression_spec.algorithm = PG_COMPRESSION_ZSTD;
+		else
+		{
+			if (stat(path, &st) == 0)
+				compression_spec.algorithm = PG_COMPRESSION_NONE;
+			else if (check_compressed_file(path, &fname, "gz"))
+				compression_spec.algorithm = PG_COMPRESSION_GZIP;
+			else if (check_compressed_file(path, &fname, "lz4"))
+				compression_spec.algorithm = PG_COMPRESSION_LZ4;
+			else if (check_compressed_file(path, &fname, "zst"))
+				compression_spec.algorithm = PG_COMPRESSION_ZSTD;
+		}
 	}
 
-	CFH = InitCompressFileHandle(compression_spec, path_is_pipe_command);  /* TODO: try to make it work also with pipes */
+	CFH = InitCompressFileHandle(compression_spec, path_is_pipe_command);
 	if (!CFH->open_func(fname, -1, mode, CFH))
 	{
 		free_keep_errno(CFH);
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index db4b627a0b8..35b7d5ab6e7 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -440,7 +440,18 @@ _LoadLOs(ArchiveHandle *AH, TocEntry *te)
 					 tocfname, line);
 
 		StartRestoreLO(AH, oid, AH->public.ropt->dropSchema);
-		snprintf(path, MAXPGPATH, "%s/%s", ctx->directory, lofname);
+		/* TODO: This logic for naming blob files is common betwen _LoadLOs an _StartLO.
+		 * Refactor in a helper function.
+		 */
+		if (AH->fSpecIsPipe)
+		{
+			pipe = replace_percent_placeholders(ctx->directory, "pipe-command", "f", lofname);
+			strcpy(path, pipe);
+		}
+		else
+		{
+			snprintf(path, MAXPGPATH, "%s/%s", ctx->directory, lofname);
+		}
 		_PrintFileData(AH, path);
 		EndRestoreLO(AH, oid);
 	}
diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c
index 46d90aec946..f552eabe0d8 100644
--- a/src/bin/pg_dump/pg_restore.c
+++ b/src/bin/pg_dump/pg_restore.c
@@ -59,7 +59,7 @@ static void usage(const char *progname);
 static void read_restore_filters(const char *filename, RestoreOptions *opts);
 static bool file_exists_in_directory(const char *dir, const char *filename);
 static int	restore_one_database(const char *inputFileSpec, RestoreOptions *opts,
-								 int numWorkers, bool append_data, int num);
+								 int numWorkers, bool append_data, int num, bool filespec_is_pipe);
 static int	read_one_statement(StringInfo inBuf, FILE *pfile);
 static int	restore_all_databases(PGconn *conn, const char *dumpdirpath,
 								  SimpleStringList db_exclude_patterns, RestoreOptions *opts, int numWorkers);
@@ -94,6 +94,7 @@ main(int argc, char **argv)
 	int			n_errors = 0;
 	bool		globals_only = false;
 	SimpleStringList db_exclude_patterns = {NULL, NULL};
+	bool 	   	filespec_is_pipe = false;
 	static int	disable_triggers = 0;
 	static int	enable_row_security = 0;
 	static int	if_exists = 0;
@@ -175,6 +176,7 @@ main(int argc, char **argv)
 		{"statistics-only", no_argument, &statistics_only, 1},
 		{"filter", required_argument, NULL, 4},
 		{"exclude-database", required_argument, NULL, 6},
+		{"pipe-command", required_argument, NULL, 7},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -356,6 +358,11 @@ main(int argc, char **argv)
 				simple_string_list_append(&db_exclude_patterns, optarg);
 				break;
 
+			case 7:			/* pipe-command */
+				inputFileSpec = pg_strdup(optarg);
+				filespec_is_pipe = true;
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -363,11 +370,23 @@ main(int argc, char **argv)
 		}
 	}
 
-	/* Get file name from command line */
+	/* Get file name from command line. Note that filename argument and pipe-command can't both be set. */
 	if (optind < argc)
+	{
+		if (filespec_is_pipe)
+		{
+			pg_log_error_hint("Only one of [filespec, --pipe-command] allowed");
+			exit_nicely(1);
+		}
 		inputFileSpec = argv[optind++];
-	else
+	}
+	/* Even if the file argument is not provided, if the pipe-command is specified, we need to use that
+	 * as the file arg and not fallback to stdio.
+	 */
+	else if (!filespec_is_pipe)
+	{
 		inputFileSpec = NULL;
+	}
 
 	/* Complain if any arguments remain */
 	if (optind < argc)
@@ -577,7 +596,7 @@ main(int argc, char **argv)
 		if (globals_only)
 			pg_fatal("option -g/--globals-only can be used only when restoring an archive created by pg_dumpall");
 
-		n_errors = restore_one_database(inputFileSpec, opts, numWorkers, false, 0);
+		n_errors = restore_one_database(inputFileSpec, opts, numWorkers, false, 0, filespec_is_pipe);
 	}
 
 	/* Done, print a summary of ignored errors during restore. */
@@ -599,12 +618,18 @@ main(int argc, char **argv)
  */
 static int
 restore_one_database(const char *inputFileSpec, RestoreOptions *opts,
-					 int numWorkers, bool append_data, int num)
+					 int numWorkers, bool append_data, int num, bool filespec_is_pipe)
 {
 	Archive    *AH;
 	int			n_errors;
 
-	AH = OpenArchive(inputFileSpec, opts->format, false); /*TODO: support pipes in restore */
+	if (filespec_is_pipe && opts->format != archDirectory)
+	{
+		pg_log_error_hint("Option --pipe-command is only supported with directory format.");
+		exit_nicely(1);
+	}
+
+	AH = OpenArchive(inputFileSpec, opts->format, filespec_is_pipe);
 
 	SetArchiveOptions(AH, NULL, opts);
 
@@ -1267,7 +1292,7 @@ restore_all_databases(PGconn *conn, const char *dumpdirpath,
 		opts->dumpStatistics = dumpStatistics;
 
 		/* Restore the single database. */
-		n_errors = restore_one_database(subdirpath, opts, numWorkers, true, count);
+		n_errors = restore_one_database(subdirpath, opts, numWorkers, true, count, false);
 
 		/* Print a summary of ignored errors during single database restore. */
 		if (n_errors)
-- 
2.49.0.1266.g31b7d2e469-goog

From ec26ad40b5bb023727045ed54c16b046c7da065a Mon Sep 17 00:00:00 2001
From: Nitin Motiani <nitinmotiani@google.com>
Date: Thu, 22 May 2025 10:20:15 +0000
Subject: [PATCH v5 5/5] [WIP] This is WIP patch for adding tests to pg_dump.pl

* The first test in the patch was the test we were originally
  trying to add but it kept failing.

* The 3 tests at the bottom were part of the debugging process and
  the logs showed that those tests would fail whenever a pipe
  was used inside the pipe command i.e. 'cat | gzip' or
  'cat > <file>'. But simple 'cat' or 'gzip' without pipe worked.

* The tests need to be cleaned up and rerun to get the exact error messages.
---
 src/bin/pg_dump/t/002_pg_dump.pl | 38 ++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 386e21e0c59..22222b2f2eb 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -476,6 +476,15 @@ my %pgdump_runs = (
 		],
 	},
 
+	# This test kept failing.
+	defaults_dir_format_pipe => {
+		test_key => 'defaults',
+		dump_cmd => [
+			'pg_dump', '-Fd', 'postgres',
+			"--pipe-command=\"cat > $tempdir/defaults_dir_format/%f\"",
+		],
+	},
+
 	# Do not use --no-sync to give test coverage for data sync.
 	defaults_parallel => {
 		test_key => 'defaults',
@@ -5103,6 +5112,35 @@ foreach my $db (sort keys %create_sql)
 	$node->safe_psql($db, $create_sql{$db});
 }
 
+# These four tests were added temporarily to more easily look through the output.
+# They failed as soon as we used a pipe of any kind whether to file or just to another
+# command. Those commands worked fine manually. So the second & fourth test where
+# we only have cat and gzip without any pipe, they work fine. But the rest don't.
+$node->command_fails_like(
+		[
+			'pg_dump', '-Fd', '-B', 'postgres',
+			"--pipe-command=\"cat > $tempdir/%f\"",],
+	qr/pg_dump: error: Failure in cat to file/,
+	'pg_dump: Failure in cat to file using pipe-command');
+
+
+$node->command_ok(
+		[
+			'pg_dump', '-Fd', '-B', 'postgres',
+			"--pipe-command=\"cat\"",], "Testing just with cat");
+
+$node->command_ok(
+		[
+			'pg_dump', '-Fd', '-B', 'postgres',
+			"--pipe-command=\"cat | gzip\"",], "Testing with cat piped to gzip");
+
+
+$node->command_ok(
+		[
+			'pg_dump', '-Fd', '-B', '-x', 'postgres',
+			"--pipe-command=\"gzip\"",], "Testing just with gzip");
+
+
 #########################################
 # Test connecting to a non-existent database
 
-- 
2.49.0.1266.g31b7d2e469-goog

From a82dd3abe0f1265125f226621afe3b4565a5f2c7 Mon Sep 17 00:00:00 2001
From: Nitin Motiani <nitinmotiani@google.com>
Date: Tue, 11 Feb 2025 08:31:02 +0000
Subject: [PATCH v5 1/5] Add pipe-command support for directory mode of pg_dump

* We add a new flag --pipe-command which can be used in directory
  mode. This allows us to support multiple streams and we can
  do post processing like compression, filtering etc. This is
  currently not possible with directory-archive format.
* Currently this flag is only supported with compression none
  and archive format directory.
* This flag can't be used with the flag --file. Only one of the
  two flags can be used at a time.
* We reuse the filename field for the --pipe-command also. And add a
  bool to specify that the field will be used as a pipe command.
* Most of the code remains as it is. The core change is that
  in case of --pipe-command, instead of fopen we do popen.
* The user would need a way to store the post-processing output
  in files. For that we support the same format as the directory
  mode currently does with the flag --file. We allow the user
  to add a format specifier %f to the --pipe-command. And for each
  stream, the format specifier is replaced with the corresponding
  file name. This file name is the same as it would have been if
  the flag --file had been used.
* To enable the above, there are a few places in the code where
  we change the file name creation logic. Currently the file name
  is appended to the directory name which is provided with --file flag.
  In case of --pipe-command, we instead replace %f with the file name.
  This change is made for the common use case and separately for
  blob files.
* There is an open question on what mode to use in case of large objects
  TOC file. Currently the code uses "ab" but that won't work for popen.
  We have proposed a few options in the comments regarding this. For the
  time being we are using mode PG_BINARY_W for the pipe use case.
---
 src/bin/pg_dump/compress_gzip.c       |  9 ++-
 src/bin/pg_dump/compress_gzip.h       |  3 +-
 src/bin/pg_dump/compress_io.c         | 26 ++++---
 src/bin/pg_dump/compress_io.h         | 11 ++-
 src/bin/pg_dump/compress_lz4.c        | 11 ++-
 src/bin/pg_dump/compress_lz4.h        |  3 +-
 src/bin/pg_dump/compress_none.c       | 28 ++++++--
 src/bin/pg_dump/compress_none.h       |  3 +-
 src/bin/pg_dump/compress_zstd.c       | 10 ++-
 src/bin/pg_dump/compress_zstd.h       |  3 +-
 src/bin/pg_dump/pg_backup.h           |  5 +-
 src/bin/pg_dump/pg_backup_archiver.c  | 22 +++---
 src/bin/pg_dump/pg_backup_archiver.h  |  1 +
 src/bin/pg_dump/pg_backup_directory.c | 99 ++++++++++++++++++++++-----
 src/bin/pg_dump/pg_dump.c             | 37 +++++++++-
 src/bin/pg_dump/pg_restore.c          |  2 +-
 16 files changed, 216 insertions(+), 57 deletions(-)

diff --git a/src/bin/pg_dump/compress_gzip.c b/src/bin/pg_dump/compress_gzip.c
index 5a30ebf9bf5..312885d7136 100644
--- a/src/bin/pg_dump/compress_gzip.c
+++ b/src/bin/pg_dump/compress_gzip.c
@@ -389,8 +389,12 @@ Gzip_open_write(const char *path, const char *mode, CompressFileHandle *CFH)
 
 void
 InitCompressFileHandleGzip(CompressFileHandle *CFH,
-						   const pg_compress_specification compression_spec)
+						   const pg_compress_specification compression_spec,
+						   bool path_is_pipe_command)
 {
+	if(path_is_pipe_command)
+		pg_fatal("cPipe command not supported for Gzip");
+
 	CFH->open_func = Gzip_open;
 	CFH->open_write_func = Gzip_open_write;
 	CFH->read_func = Gzip_read;
@@ -415,7 +419,8 @@ InitCompressorGzip(CompressorState *cs,
 
 void
 InitCompressFileHandleGzip(CompressFileHandle *CFH,
-						   const pg_compress_specification compression_spec)
+						   const pg_compress_specification compression_spec,
+						   bool path_is_pipe_command)
 {
 	pg_fatal("this build does not support compression with %s", "gzip");
 }
diff --git a/src/bin/pg_dump/compress_gzip.h b/src/bin/pg_dump/compress_gzip.h
index 3bef0d5b1b8..ccf2479cf3b 100644
--- a/src/bin/pg_dump/compress_gzip.h
+++ b/src/bin/pg_dump/compress_gzip.h
@@ -19,6 +19,7 @@
 extern void InitCompressorGzip(CompressorState *cs,
 							   const pg_compress_specification compression_spec);
 extern void InitCompressFileHandleGzip(CompressFileHandle *CFH,
-									   const pg_compress_specification compression_spec);
+									   const pg_compress_specification compression_spec,
+									   bool path_is_pipe_command);
 
 #endif							/* _COMPRESS_GZIP_H_ */
diff --git a/src/bin/pg_dump/compress_io.c b/src/bin/pg_dump/compress_io.c
index 8c3d9c911c4..b3e1a133af8 100644
--- a/src/bin/pg_dump/compress_io.c
+++ b/src/bin/pg_dump/compress_io.c
@@ -191,20 +191,29 @@ free_keep_errno(void *p)
  * Initialize a compress file handle for the specified compression algorithm.
  */
 CompressFileHandle *
-InitCompressFileHandle(const pg_compress_specification compression_spec)
+InitCompressFileHandle(const pg_compress_specification compression_spec,
+			bool path_is_pipe_command)
 {
 	CompressFileHandle *CFH;
 
+
 	CFH = pg_malloc0(sizeof(CompressFileHandle));
 
-	if (compression_spec.algorithm == PG_COMPRESSION_NONE)
-		InitCompressFileHandleNone(CFH, compression_spec);
+	/* TODO: Currently always set to non-compressed when path_is_pipe_command
+	 * assuming that external compressor as part of pipe is nore efficient
+	 * should review after POC
+	 */
+	if (path_is_pipe_command)
+		InitCompressFileHandleNone(CFH, compression_spec, path_is_pipe_command);
+
+	else if (compression_spec.algorithm == PG_COMPRESSION_NONE)
+		InitCompressFileHandleNone(CFH, compression_spec, path_is_pipe_command);
 	else if (compression_spec.algorithm == PG_COMPRESSION_GZIP)
-		InitCompressFileHandleGzip(CFH, compression_spec);
+		InitCompressFileHandleGzip(CFH, compression_spec, path_is_pipe_command);
 	else if (compression_spec.algorithm == PG_COMPRESSION_LZ4)
-		InitCompressFileHandleLZ4(CFH, compression_spec);
+		InitCompressFileHandleLZ4(CFH, compression_spec, path_is_pipe_command);
 	else if (compression_spec.algorithm == PG_COMPRESSION_ZSTD)
-		InitCompressFileHandleZstd(CFH, compression_spec);
+		InitCompressFileHandleZstd(CFH, compression_spec, path_is_pipe_command);
 
 	return CFH;
 }
@@ -237,7 +246,8 @@ check_compressed_file(const char *path, char **fname, char *ext)
  * On failure, return NULL with an error code in errno.
  */
 CompressFileHandle *
-InitDiscoverCompressFileHandle(const char *path, const char *mode)
+InitDiscoverCompressFileHandle(const char *path, const char *mode,
+				bool path_is_pipe_command)
 {
 	CompressFileHandle *CFH = NULL;
 	struct stat st;
@@ -268,7 +278,7 @@ InitDiscoverCompressFileHandle(const char *path, const char *mode)
 			compression_spec.algorithm = PG_COMPRESSION_ZSTD;
 	}
 
-	CFH = InitCompressFileHandle(compression_spec);
+	CFH = InitCompressFileHandle(compression_spec, path_is_pipe_command);  /* TODO: try to make it work also with pipes */
 	if (!CFH->open_func(fname, -1, mode, CFH))
 	{
 		free_keep_errno(CFH);
diff --git a/src/bin/pg_dump/compress_io.h b/src/bin/pg_dump/compress_io.h
index db9b38744c8..affc287c66e 100644
--- a/src/bin/pg_dump/compress_io.h
+++ b/src/bin/pg_dump/compress_io.h
@@ -185,6 +185,11 @@ struct CompressFileHandle
 	 */
 	pg_compress_specification compression_spec;
 
+	/*
+	 * Compression specification for this file handle.
+	 */
+	bool path_is_pipe_command;
+
 	/*
 	 * Private data to be used by the compressor.
 	 */
@@ -194,7 +199,8 @@ struct CompressFileHandle
 /*
  * Initialize a compress file handle with the requested compression.
  */
-extern CompressFileHandle *InitCompressFileHandle(const pg_compress_specification compression_spec);
+extern CompressFileHandle *InitCompressFileHandle(const pg_compress_specification compression_spec,
+							bool path_is_pipe_command);
 
 /*
  * Initialize a compress file stream. Infer the compression algorithm
@@ -202,6 +208,7 @@ extern CompressFileHandle *InitCompressFileHandle(const pg_compress_specificatio
  * suffixes in 'path'.
  */
 extern CompressFileHandle *InitDiscoverCompressFileHandle(const char *path,
-														  const char *mode);
+														  const char *mode,
+														  bool path_is_pipe_command);
 extern bool EndCompressFileHandle(CompressFileHandle *CFH);
 #endif
diff --git a/src/bin/pg_dump/compress_lz4.c b/src/bin/pg_dump/compress_lz4.c
index e99f0cad71f..7e7713936bf 100644
--- a/src/bin/pg_dump/compress_lz4.c
+++ b/src/bin/pg_dump/compress_lz4.c
@@ -751,10 +751,14 @@ LZ4Stream_open_write(const char *path, const char *mode, CompressFileHandle *CFH
  */
 void
 InitCompressFileHandleLZ4(CompressFileHandle *CFH,
-						  const pg_compress_specification compression_spec)
+						  const pg_compress_specification compression_spec,
+						  bool path_is_pipe_command)
 {
 	LZ4State   *state;
 
+	if(path_is_pipe_command)
+		pg_fatal("cPipe command not supported for LZ4");
+
 	CFH->open_func = LZ4Stream_open;
 	CFH->open_write_func = LZ4Stream_open_write;
 	CFH->read_func = LZ4Stream_read;
@@ -770,6 +774,8 @@ InitCompressFileHandleLZ4(CompressFileHandle *CFH,
 	if (CFH->compression_spec.level >= 0)
 		state->prefs.compressionLevel = CFH->compression_spec.level;
 
+	CFH->path_is_pipe_command = path_is_pipe_command;
+
 	CFH->private_data = state;
 }
 #else							/* USE_LZ4 */
@@ -782,7 +788,8 @@ InitCompressorLZ4(CompressorState *cs,
 
 void
 InitCompressFileHandleLZ4(CompressFileHandle *CFH,
-						  const pg_compress_specification compression_spec)
+						  const pg_compress_specification compression_spec,
+						  bool path_is_pipe_command)
 {
 	pg_fatal("this build does not support compression with %s", "LZ4");
 }
diff --git a/src/bin/pg_dump/compress_lz4.h b/src/bin/pg_dump/compress_lz4.h
index 7f7216cc648..d52e6071519 100644
--- a/src/bin/pg_dump/compress_lz4.h
+++ b/src/bin/pg_dump/compress_lz4.h
@@ -19,6 +19,7 @@
 extern void InitCompressorLZ4(CompressorState *cs,
 							  const pg_compress_specification compression_spec);
 extern void InitCompressFileHandleLZ4(CompressFileHandle *CFH,
-									  const pg_compress_specification compression_spec);
+									  const pg_compress_specification compression_spec,
+									  bool path_is_pipe_command);
 
 #endif							/* _COMPRESS_LZ4_H_ */
diff --git a/src/bin/pg_dump/compress_none.c b/src/bin/pg_dump/compress_none.c
index 3fc89c99854..b7392824b68 100644
--- a/src/bin/pg_dump/compress_none.c
+++ b/src/bin/pg_dump/compress_none.c
@@ -153,7 +153,12 @@ close_none(CompressFileHandle *CFH)
 	CFH->private_data = NULL;
 
 	if (fp)
-		ret = fclose(fp);
+	{
+		if(CFH->path_is_pipe_command)
+			ret = pclose(fp);
+		else
+			ret = fclose(fp);
+	}
 
 	return ret == 0;
 }
@@ -172,7 +177,12 @@ open_none(const char *path, int fd, const char *mode, CompressFileHandle *CFH)
 	if (fd >= 0)
 		CFH->private_data = fdopen(dup(fd), mode);
 	else
-		CFH->private_data = fopen(path, mode);
+	{
+		if (CFH->path_is_pipe_command)
+			CFH->private_data = popen(path, mode);
+		else
+			CFH->private_data = fopen(path, mode);
+	}
 
 	if (CFH->private_data == NULL)
 		return false;
@@ -185,7 +195,14 @@ open_write_none(const char *path, const char *mode, CompressFileHandle *CFH)
 {
 	Assert(CFH->private_data == NULL);
 
-	CFH->private_data = fopen(path, mode);
+	pg_log_debug("Opening %s, pipe is %s",
+				 path, CFH->path_is_pipe_command ? "true" : "false");
+
+	if (CFH->path_is_pipe_command)
+		CFH->private_data = popen(path, mode);
+	else
+		CFH->private_data = fopen(path, mode);
+
 	if (CFH->private_data == NULL)
 		return false;
 
@@ -198,7 +215,8 @@ open_write_none(const char *path, const char *mode, CompressFileHandle *CFH)
 
 void
 InitCompressFileHandleNone(CompressFileHandle *CFH,
-						   const pg_compress_specification compression_spec)
+						   const pg_compress_specification compression_spec,
+						   bool path_is_pipe_command)
 {
 	CFH->open_func = open_none;
 	CFH->open_write_func = open_write_none;
@@ -210,5 +228,7 @@ InitCompressFileHandleNone(CompressFileHandle *CFH,
 	CFH->eof_func = eof_none;
 	CFH->get_error_func = get_error_none;
 
+	CFH->path_is_pipe_command = path_is_pipe_command;
+
 	CFH->private_data = NULL;
 }
diff --git a/src/bin/pg_dump/compress_none.h b/src/bin/pg_dump/compress_none.h
index f927f196c36..1399c8bde3b 100644
--- a/src/bin/pg_dump/compress_none.h
+++ b/src/bin/pg_dump/compress_none.h
@@ -19,6 +19,7 @@
 extern void InitCompressorNone(CompressorState *cs,
 							   const pg_compress_specification compression_spec);
 extern void InitCompressFileHandleNone(CompressFileHandle *CFH,
-									   const pg_compress_specification compression_spec);
+									   const pg_compress_specification compression_spec,
+									   bool path_is_pipe_command);
 
 #endif							/* _COMPRESS_NONE_H_ */
diff --git a/src/bin/pg_dump/compress_zstd.c b/src/bin/pg_dump/compress_zstd.c
index cb595b10c2d..a7a37643acd 100644
--- a/src/bin/pg_dump/compress_zstd.c
+++ b/src/bin/pg_dump/compress_zstd.c
@@ -26,7 +26,8 @@ InitCompressorZstd(CompressorState *cs, const pg_compress_specification compress
 }
 
 void
-InitCompressFileHandleZstd(CompressFileHandle *CFH, const pg_compress_specification compression_spec)
+InitCompressFileHandleZstd(CompressFileHandle *CFH, const pg_compress_specification compression_spec,
+				bool path_is_pipe_command)
 {
 	pg_fatal("this build does not support compression with %s", "ZSTD");
 }
@@ -524,8 +525,12 @@ Zstd_get_error(CompressFileHandle *CFH)
 
 void
 InitCompressFileHandleZstd(CompressFileHandle *CFH,
-						   const pg_compress_specification compression_spec)
+						   const pg_compress_specification compression_spec,
+						   bool path_is_pipe_command)
 {
+	if(path_is_pipe_command)
+		pg_fatal("cPipe command not supported for Zstd");
+
 	CFH->open_func = Zstd_open;
 	CFH->open_write_func = Zstd_open_write;
 	CFH->read_func = Zstd_read;
@@ -537,6 +542,7 @@ InitCompressFileHandleZstd(CompressFileHandle *CFH,
 	CFH->get_error_func = Zstd_get_error;
 
 	CFH->compression_spec = compression_spec;
+	CFH->path_is_pipe_command = path_is_pipe_command;
 
 	CFH->private_data = NULL;
 }
diff --git a/src/bin/pg_dump/compress_zstd.h b/src/bin/pg_dump/compress_zstd.h
index af21db48ded..1644b6d6eba 100644
--- a/src/bin/pg_dump/compress_zstd.h
+++ b/src/bin/pg_dump/compress_zstd.h
@@ -20,6 +20,7 @@
 extern void InitCompressorZstd(CompressorState *cs,
 							   const pg_compress_specification compression_spec);
 extern void InitCompressFileHandleZstd(CompressFileHandle *CFH,
-									   const pg_compress_specification compression_spec);
+									   const pg_compress_specification compression_spec,
+									   bool path_is_pipe_command);
 
 #endif							/* COMPRESS_ZSTD_H */
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index af0007fb6d2..18be674ab7f 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -311,14 +311,15 @@ extern void ProcessArchiveRestoreOptions(Archive *AHX);
 extern void RestoreArchive(Archive *AHX, bool append_data);
 
 /* Open an existing archive */
-extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
+extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt, bool FileSpecIsPipe);
 
 /* Create a new archive */
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
 							  SetupWorkerPtrType setupDumpWorker,
-							  DataDirSyncMethod sync_method);
+							  DataDirSyncMethod sync_method,
+							  bool FileSpecIsPipe); /* ^^ what are the casing rules here ?? */
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 197c1295d93..af34af6b380 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -54,7 +54,7 @@ static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
 							   SetupWorkerPtrType setupWorkerPtr,
-							   DataDirSyncMethod sync_method);
+							   DataDirSyncMethod sync_method, bool FileSpecIsPipe);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, const char *pfx);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -230,11 +230,12 @@ CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
 			  SetupWorkerPtrType setupDumpWorker,
-			  DataDirSyncMethod sync_method)
+			  DataDirSyncMethod sync_method,
+			  bool FileSpecIsPipe)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker, sync_method);
+								 dosync, mode, setupDumpWorker, sync_method, FileSpecIsPipe);
 
 	return (Archive *) AH;
 }
@@ -242,7 +243,7 @@ CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 /* Open an existing archive */
 /* Public */
 Archive *
-OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
+OpenArchive(const char *FileSpec, const ArchiveFormat fmt, bool FileSpecIsPipe)
 {
 	ArchiveHandle *AH;
 	pg_compress_specification compression_spec = {0};
@@ -250,7 +251,7 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
 				  archModeRead, setupRestoreWorker,
-				  DATA_DIR_SYNC_METHOD_FSYNC);
+				  DATA_DIR_SYNC_METHOD_FSYNC, FileSpecIsPipe);
 
 	return (Archive *) AH;
 }
@@ -1705,7 +1706,7 @@ SetOutput(ArchiveHandle *AH, const char *filename,
 	else
 		mode = PG_BINARY_W;
 
-	CFH = InitCompressFileHandle(compression_spec);
+	CFH = InitCompressFileHandle(compression_spec, AH->fSpecIsPipe);
 
 	if (!CFH->open_func(filename, fn, mode, CFH))
 	{
@@ -2362,7 +2363,8 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method)
+		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method,
+		 bool FileSpecIsPipe)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2403,6 +2405,8 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	else
 		AH->fSpec = NULL;
 
+	AH->fSpecIsPipe = FileSpecIsPipe;
+
 	AH->currUser = NULL;		/* unknown */
 	AH->currSchema = NULL;		/* ditto */
 	AH->currTablespace = NULL;	/* ditto */
@@ -2415,14 +2419,14 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
-	AH->dosync = dosync;
+	AH->dosync = FileSpecIsPipe ? false : dosync;
 	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
 	/* Open stdout with no compression for AH output handle */
 	out_compress_spec.algorithm = PG_COMPRESSION_NONE;
-	CFH = InitCompressFileHandle(out_compress_spec);
+	CFH = InitCompressFileHandle(out_compress_spec, AH->fSpecIsPipe);
 	if (!CFH->open_func(NULL, fileno(stdout), PG_BINARY_A, CFH))
 		pg_fatal("could not open stdout for appending: %m");
 	AH->OF = CFH;
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 365073b3eae..d7fa3086184 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -301,6 +301,7 @@ struct _archiveHandle
 	int			loCount;		/* # of LOs restored */
 
 	char	   *fSpec;			/* Archive File Spec */
+	bool        fSpecIsPipe;     /* fSpec is a pipe command template requiring replacing %f with file name */
 	FILE	   *FH;				/* General purpose file handle */
 	void	   *OF;				/* Output file */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 21b00792a8a..db4b627a0b8 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -39,7 +39,8 @@
 #include <dirent.h>
 #include <sys/stat.h>
 
-#include "common/file_utils.h"
+//#include "common/file_utils.h"
+#include "common/percentrepl.h"
 #include "compress_io.h"
 #include "dumputils.h"
 #include "parallel.h"
@@ -157,8 +158,11 @@ InitArchiveFmt_Directory(ArchiveHandle *AH)
 
 	if (AH->mode == archModeWrite)
 	{
-		/* we accept an empty existing directory */
-		create_or_open_dir(ctx->directory);
+		if(!AH->fSpecIsPipe) /* no checks for pipe */
+		{
+			/* we accept an empty existing directory */
+			create_or_open_dir(ctx->directory);
+		}
 	}
 	else
 	{							/* Read Mode */
@@ -167,7 +171,7 @@ InitArchiveFmt_Directory(ArchiveHandle *AH)
 
 		setFilePath(AH, fname, "toc.dat");
 
-		tocFH = InitDiscoverCompressFileHandle(fname, PG_BINARY_R);
+		tocFH = InitDiscoverCompressFileHandle(fname, PG_BINARY_R, AH->fSpecIsPipe);
 		if (tocFH == NULL)
 			pg_fatal("could not open input file \"%s\": %m", fname);
 
@@ -295,7 +299,7 @@ _StartData(ArchiveHandle *AH, TocEntry *te)
 
 	setFilePath(AH, fname, tctx->filename);
 
-	ctx->dataFH = InitCompressFileHandle(AH->compression_spec);
+	ctx->dataFH = InitCompressFileHandle(AH->compression_spec, AH->fSpecIsPipe);
 
 	if (!ctx->dataFH->open_write_func(fname, PG_BINARY_W, ctx->dataFH))
 		pg_fatal("could not open output file \"%s\": %m", fname);
@@ -359,7 +363,7 @@ _PrintFileData(ArchiveHandle *AH, char *filename)
 	if (!filename)
 		return;
 
-	CFH = InitDiscoverCompressFileHandle(filename, PG_BINARY_R);
+	CFH = InitDiscoverCompressFileHandle(filename, PG_BINARY_R, AH->fSpecIsPipe);
 	if (!CFH)
 		pg_fatal("could not open input file \"%s\": %m", filename);
 
@@ -417,7 +421,7 @@ _LoadLOs(ArchiveHandle *AH, TocEntry *te)
 	 */
 	setFilePath(AH, tocfname, tctx->filename);
 
-	CFH = ctx->LOsTocFH = InitDiscoverCompressFileHandle(tocfname, PG_BINARY_R);
+	CFH = ctx->LOsTocFH = InitDiscoverCompressFileHandle(tocfname, PG_BINARY_R, AH->fSpecIsPipe);
 
 	if (ctx->LOsTocFH == NULL)
 		pg_fatal("could not open large object TOC file \"%s\" for input: %m",
@@ -428,6 +432,7 @@ _LoadLOs(ArchiveHandle *AH, TocEntry *te)
 	{
 		char		lofname[MAXPGPATH + 1];
 		char		path[MAXPGPATH];
+		char* pipe;
 
 		/* Can't overflow because line and lofname are the same length */
 		if (sscanf(line, "%u %" CppAsString2(MAXPGPATH) "s\n", &oid, lofname) != 2)
@@ -563,7 +568,7 @@ _CloseArchive(ArchiveHandle *AH)
 
 		/* The TOC is always created uncompressed */
 		compression_spec.algorithm = PG_COMPRESSION_NONE;
-		tocFH = InitCompressFileHandle(compression_spec);
+		tocFH = InitCompressFileHandle(compression_spec, AH->fSpecIsPipe);
 		if (!tocFH->open_write_func(fname, PG_BINARY_W, tocFH))
 			pg_fatal("could not open output file \"%s\": %m", fname);
 		ctx->dataFH = tocFH;
@@ -624,13 +629,42 @@ _StartLOs(ArchiveHandle *AH, TocEntry *te)
 	lclTocEntry *tctx = (lclTocEntry *) te->formatData;
 	pg_compress_specification compression_spec = {0};
 	char		fname[MAXPGPATH];
+	const char *mode;
 
 	setFilePath(AH, fname, tctx->filename);
 
 	/* The LO TOC file is never compressed */
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
-	ctx->LOsTocFH = InitCompressFileHandle(compression_spec);
-	if (!ctx->LOsTocFH->open_write_func(fname, "ab", ctx->LOsTocFH))
+	ctx->LOsTocFH = InitCompressFileHandle(compression_spec, AH->fSpecIsPipe);
+	/* TODO: Finalize the correct approach for the mode.
+	 * The mode for the LOs TOC file has been "ab" from the start. That
+	 * is something we can't do for pipe-command as popen only supports
+	 * read and write. Just changing it to 'w' was not expected to be enough
+	 * and one possible solution considered is to open it in 'w' mode and
+	 * keep it open till all the LOs in the dump group are done.
+	 *
+	 * The analysis of the current code shows that there is one ToCEntry
+	 * per blob group. And it is written by @WriteDataChunksForToCEntry.
+	 * This function calls _StartLOs once before the dumper function and
+	 * and _EndLOs once after the dumper. And the dumper dumps all the
+	 * LOs in the group. So a blob_NNN.toc is only opened once and closed
+	 * after all the entries are written. Therefore the mode can be made 'w'
+	 * for all the cases. We tested changing the mode to PG_BINARY_W and
+	 * the tests passed. But in case there are some missing scenarios, we
+	 * have not made that change here. Instead for now only doing
+	 * it for the pipe command.
+	 * In short there are 3 solutions :
+	 * 1. Change the mode for everything (preferred)
+	 * 2. Change it only for pipe-command (done for time-being)
+	 * 3. Change it for pipe-command and then cache those handles
+	 *    and close them in the end (based on the code review, we might
+	 *    pick this).
+	 */
+	if (AH->fSpecIsPipe)
+		mode = PG_BINARY_W;
+	else
+		mode = "ab";
+	if (!ctx->LOsTocFH->open_write_func(fname, mode, ctx->LOsTocFH))
 		pg_fatal("could not open output file \"%s\": %m", fname);
 }
 
@@ -644,10 +678,22 @@ _StartLO(ArchiveHandle *AH, TocEntry *te, Oid oid)
 {
 	lclContext *ctx = (lclContext *) AH->formatData;
 	char		fname[MAXPGPATH];
+	char* pipe;
+	char blob_name[MAXPGPATH];
 
-	snprintf(fname, MAXPGPATH, "%s/blob_%u.dat", ctx->directory, oid);
+	if(AH->fSpecIsPipe)
+	{
+		snprintf(blob_name, MAXPGPATH, "blob_%u.dat", oid);
+		pipe = replace_percent_placeholders(ctx->directory, "pipe-command", "f", blob_name);
+		strcpy(fname, pipe);
+		/* TODO:figure out how to free the allocated string when replace_percent_placeholders isused in frontend*/
+	}
+	 else
+	{
+		snprintf(fname, MAXPGPATH, "%s/blob_%u.dat", ctx->directory, oid);
+	}
 
-	ctx->dataFH = InitCompressFileHandle(AH->compression_spec);
+	ctx->dataFH = InitCompressFileHandle(AH->compression_spec, AH->fSpecIsPipe);
 	if (!ctx->dataFH->open_write_func(fname, PG_BINARY_W, ctx->dataFH))
 		pg_fatal("could not open output file \"%s\": %m", fname);
 }
@@ -708,15 +754,26 @@ setFilePath(ArchiveHandle *AH, char *buf, const char *relativeFilename)
 {
 	lclContext *ctx = (lclContext *) AH->formatData;
 	char	   *dname;
+	char	   *pipe;
 
 	dname = ctx->directory;
 
-	if (strlen(dname) + 1 + strlen(relativeFilename) + 1 > MAXPGPATH)
-		pg_fatal("file name too long: \"%s\"", dname);
 
-	strcpy(buf, dname);
-	strcat(buf, "/");
-	strcat(buf, relativeFilename);
+	if(AH->fSpecIsPipe)
+	{
+		pipe = replace_percent_placeholders(dname, "pipe-command", "f", relativeFilename);
+		strcpy(buf, pipe);
+		/* TODO:figure out how to free the allocated string when replace_percent_placeholders isused in frontend*/
+	}
+	else /* replace all ocurrences of %f in dname with relativeFilename */
+	{
+		if (strlen(dname) + 1 + strlen(relativeFilename) + 1 > MAXPGPATH)
+			pg_fatal("file name too long: \"%s\"", dname);
+
+		strcpy(buf, dname);
+		strcat(buf, "/");
+		strcat(buf, relativeFilename);
+	}
 }
 
 /*
@@ -758,17 +815,23 @@ _PrepParallelRestore(ArchiveHandle *AH)
 		 * only need an approximate indicator of that.
 		 */
 		setFilePath(AH, fname, tctx->filename);
+		pg_log_error("filename: %s", fname);
 
 		if (stat(fname, &st) == 0)
 			te->dataLength = st.st_size;
 		else if (AH->compression_spec.algorithm != PG_COMPRESSION_NONE)
 		{
+			if(AH->fSpecIsPipe)
+				pg_log_error("pipe and compressed");
 			if (AH->compression_spec.algorithm == PG_COMPRESSION_GZIP)
 				strlcat(fname, ".gz", sizeof(fname));
 			else if (AH->compression_spec.algorithm == PG_COMPRESSION_LZ4)
 				strlcat(fname, ".lz4", sizeof(fname));
-			else if (AH->compression_spec.algorithm == PG_COMPRESSION_ZSTD)
+			else if (AH->compression_spec.algorithm == PG_COMPRESSION_ZSTD){
+				pg_log_error("filename: %s", fname);
 				strlcat(fname, ".zst", sizeof(fname));
+				pg_log_error("filename: %s", fname);
+			}
 
 			if (stat(fname, &st) == 0)
 				te->dataLength = st.st_size;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 37432e66efd..689b1859067 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -411,6 +411,7 @@ main(int argc, char **argv)
 {
 	int			c;
 	const char *filename = NULL;
+	bool        filename_is_pipe = false;
 	const char *format = "p";
 	TableInfo  *tblinfo;
 	int			numTables;
@@ -530,6 +531,7 @@ main(int argc, char **argv)
 		{"filter", required_argument, NULL, 16},
 		{"exclude-extension", required_argument, NULL, 17},
 		{"sequence-data", no_argument, &dopt.sequence_data, 1},
+		{"pipe-command", required_argument, NULL, 25},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -601,7 +603,13 @@ main(int argc, char **argv)
 				break;
 
 			case 'f':
+				if (filename != NULL)
+				{
+					pg_log_error_hint("Only one of [--file, --pipe-command] allowed");
+					exit_nicely(1);
+				}
 				filename = pg_strdup(optarg);
+				filename_is_pipe = false; /* it already is, setting again here just for clarity */
 				break;
 
 			case 'F':
@@ -798,6 +806,16 @@ main(int argc, char **argv)
 				with_statistics = true;
 				break;
 
+			case 25:			/* pipe command */
+				if (filename != NULL)
+				{
+					pg_log_error_hint("Only one of [--file, --pipe-command] allowed");
+					exit_nicely(1);
+				}
+				filename = pg_strdup(optarg);
+				filename_is_pipe = true;
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -890,13 +908,26 @@ main(int argc, char **argv)
 	if (archiveFormat == archNull)
 		plainText = 1;
 
+	if (filename_is_pipe && archiveFormat != archDirectory)
+	{
+		pg_log_error_hint("Option --pipe-command is only supported with directory format.");
+		exit_nicely(1);
+	}
+
+	if (filename_is_pipe && strcmp(compression_algorithm_str, "none") != 0)
+	{
+		pg_log_error_hint("Option --pipe-command is not supported with any compression type.");
+		exit_nicely(1);
+	}
+
 	/*
 	 * Custom and directory formats are compressed by default with gzip when
 	 * available, not the others.  If gzip is not available, no compression is
-	 * done by default.
+	 * done by default. If directory format is being used with pipe-command,
+	 * no compression is done.
 	 */
 	if ((archiveFormat == archCustom || archiveFormat == archDirectory) &&
-		!user_compression_defined)
+		!filename_is_pipe && !user_compression_defined)
 	{
 #ifdef HAVE_LIBZ
 		compression_algorithm_str = "gzip";
@@ -946,7 +977,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker, sync_method);
+						 dosync, archiveMode, setupDumpWorker, sync_method, filename_is_pipe);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c
index f2182e91825..46d90aec946 100644
--- a/src/bin/pg_dump/pg_restore.c
+++ b/src/bin/pg_dump/pg_restore.c
@@ -604,7 +604,7 @@ restore_one_database(const char *inputFileSpec, RestoreOptions *opts,
 	Archive    *AH;
 	int			n_errors;
 
-	AH = OpenArchive(inputFileSpec, opts->format);
+	AH = OpenArchive(inputFileSpec, opts->format, false); /*TODO: support pipes in restore */
 
 	SetArchiveOptions(AH, NULL, opts);
 
-- 
2.49.0.1266.g31b7d2e469-goog

From 7df17cbe5e32226c72a63fb6c97b308908dcf849 Mon Sep 17 00:00:00 2001
From: Nitin Motiani <nitinmotiani@google.com>
Date: Fri, 4 Apr 2025 14:34:48 +0000
Subject: [PATCH v5 4/5] Add documentation for pipe-command in pg_dump and
 pg_restore

* Add the descriptions of the new flags and constraints
  regarding which mode and other flags they can't be used with.
* Explain the purpose of the flags.
* Add a few examples of the usage of the flags.
---
 doc/src/sgml/ref/pg_dump.sgml    | 56 ++++++++++++++++++++++++++
 doc/src/sgml/ref/pg_restore.sgml | 68 +++++++++++++++++++++++++++++++-
 2 files changed, 123 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index d7595a7e546..18bc67d61fc 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -287,6 +287,7 @@ PostgreSQL documentation
         specifies the target directory instead of a file. In this case the
         directory is created by <command>pg_dump</command> and must not exist
         before.
+        This option and <option>--pipe-command</option> can't be used together.
        </para>
       </listitem>
      </varlistentry>
@@ -1234,6 +1235,32 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--pipe-command</option></term>
+      <listitem>
+       <para>
+        This option is only supported with the directory output
+        format. It can be used to write to multiple streams which
+        otherwise would not be possible with the directory mode.
+        For each stream, it starts a process which runs the
+        specified command and pipes the pg_dump output to this
+        process.
+        This option is not valid if <option>--file</option>
+        is also specified.
+       </para>
+       <para>
+        The pipe-command can be used to perform operations like compress
+        using a custom algorithm, filter, or write the output to a cloud
+        storage etc. The user would need a way to pipe the final output of
+        each stream to a file. To handle that, the pipe command supports a format
+        specifier %f. And all the instances of %f in the command string
+        will be replaced with the corresponding file name which
+        would have been used in the directory mode with <option>--file</option>.
+        See <xref linkend="pg-dump-examples"/> below.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--quote-all-identifiers</option></term>
       <listitem>
@@ -1783,6 +1810,35 @@ CREATE DATABASE foo WITH TEMPLATE template0;
 </screen>
   </para>
 
+  <para>
+   To use pipe-command to dump a database into a directory-format archive
+   (the directory <literal>dumpdir</literal> needs to exist before running the command).
+
+<screen>
+<prompt>$</prompt> <userinput>pg_dump -Fd mydb --pipe-command="cat > dumpdir/%f"</userinput>
+</screen>
+  </para>
+
+  <para>
+   To use pipe-command to dump a database into a directory-format archive
+   in parallel with 5 worker jobs (the directory <literal>dumpdir</literal> needs to exist
+   before running the command).
+
+<screen>
+<prompt>$</prompt> <userinput>pg_dump -Fd mydb -j 5 --pipe-command="cat > dumpdir/%f"</userinput>
+</screen>
+  </para>
+
+  <para>
+   To use pipe-command to compress and dump a database into a
+   directory-format archive (the directory <literal>dumpdir</literal> needs to
+   exist before running the command).
+
+<screen>
+<prompt>$</prompt> <userinput>pg_dump -Fd mydb --pipe-command="gzip > dumpdir/%f.gz"</userinput>
+</screen>
+  </para>
+
   <para>
    To reload an archive file into a (freshly created) database named
    <literal>newdb</literal>:
diff --git a/doc/src/sgml/ref/pg_restore.sgml b/doc/src/sgml/ref/pg_restore.sgml
index 2295df62d03..5a929162702 100644
--- a/doc/src/sgml/ref/pg_restore.sgml
+++ b/doc/src/sgml/ref/pg_restore.sgml
@@ -93,7 +93,10 @@ PostgreSQL documentation
        <para>
        Specifies the location of the archive file (or directory, for a
        directory-format archive) to be restored.
-       If not specified, the standard input is used.
+       This option and <option>--pipe-command</option> can't be set
+       at the same time.
+       If neither this option nor <option>--pipe-command</option> is specified,
+       the standard input is used.
        </para>
       </listitem>
      </varlistentry>
@@ -842,6 +845,32 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--pipe-command</option></term>
+      <listitem>
+       <para>
+        This option is only supported with the directory output
+        format. It can be used to read from multiple streams which
+        otherwise would not be possible with the directory mode.
+        For each stream, it starts a process which runs the
+        specified command and pipes its output to the pg_restore process.
+        This option is not valid if <option>filename</option> is also specified.
+       </para>
+       <para>
+        The pipe-command can be used to perform operations like
+        decompress using a custom algorithm, filter, or read from
+        a cloud storage. When reading from the pg_dump output,
+        the user would need a way to read the correct file in each
+        stream. To handle that, the pipe command supports a format
+        specifier %f. And all the instances of %f in the command string
+        will be replaced with the corresponding file name which
+        would have been used in the directory mode with <option>filename</option>.
+        This is same as the <option>--pipe-command</option> of pg-dump.
+        See <xref linkend="app-pgrestore-examples"/> below.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
        <term><option>--section=<replaceable class="parameter">sectionname</replaceable></option></term>
        <listitem>
@@ -1263,6 +1292,43 @@ CREATE DATABASE foo WITH TEMPLATE template0;
 <prompt>$</prompt> <userinput>pg_restore -L db.list db.dump</userinput>
 </screen></para>
 
+  <para>
+   To use pg_restore with pipe-command to recreate from a dump in
+   directory-archive format. The database should not exist beforehand.
+   Assume in this example that the dump in directory-archive format is
+   stored in <literal>dumpdir</literal>.
+
+<screen>
+<prompt>$</prompt> <userinput>pg_restore -C -Fd -d postgres --pipe-commnad="cat dumpdir/%f"</userinput>
+</screen>
+  </para>
+
+  <para>
+   To use pg_restore with pipe-command to first decompress and then
+   recreate from a dump in directory-archive format. The database
+   should not exist beforehand.
+   Assume in this example that the dump in directory-archive format is
+   stored in <literal>dumpdir</literal>. And all files are
+   <literal>gzip</literal> compressed.
+
+<screen>
+<prompt>$</prompt> <userinput>pg_restore -C -Fd -d postgres --pipe-commnad="cat dumpdir/%f.gz | gunzip"</userinput>
+</screen>
+  </para>
+
+  <para>
+   To use pipe-command along with <option>-L</option> to recreate only
+   selectd items from a dump in the directory-archive format.
+   The database should not exist beforehand.
+   Assume in this example that the dump in directory-archive format is
+   stored in dumpdir.
+   The <literal>db.list</literal> file is the same as one used in the previous example with <option>-L</option>
+
+<screen>
+<prompt>$</prompt> <userinput>pg_restore -C -Fd -d postgres --pipe-commnad="cat dumpdir/%f" -L db.list</userinput>
+</screen>
+  </para>
+
  </refsect1>
 
  <refsect1>
-- 
2.49.0.1266.g31b7d2e469-goog