pg.ddx.io  pgsql-hackers@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: Justin Pryzby <pryzby@telsasoft.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Alexander Korotkov <a.korotkov@postgrespro.ru>
Cc: David Steele <david@pgmasters.net>
Cc: Ildus Kurbangaliev <i.kurbangaliev@gmail.com>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: pgsql-hackers@lists.postgresql.org
Subject: Re: [HACKERS] Custom compression methods
Date: Sun, 14 Feb 2021 12:49:40 -0600
Message-ID: <20210214184940.GL1793@telsasoft.com> (raw)
In-Reply-To: <CA+TgmoZ9Rap=NuJLSvw2u=9fibUdB2L_Cs2Wb8FD49vhiXsdpQ@mail.gmail.com>
References: <20210130071638.GG7450@telsasoft.com>
	<CA+TgmoZ50fvbfhoqXZWAnrFx+_7qOiPE7xNXfat0h7awbm_nxw@mail.gmail.com>
	<CA+TgmoZzQWBEkoZEon=TXwJhwZGXPUW7ma4xxh9DaJoHB8CfWQ@mail.gmail.com>
	<CAFiTN-v9Cs1MORnp-3bGZ5QBwr5v3VarSvfaDizHi1acXES5xQ@mail.gmail.com>
	<CAFiTN-unUNcgU0M29bdTrGHA4agK8T7g+dpMyVMeRtPawSWhCw@mail.gmail.com>
	<CAFiTN-tZgTTejUb1tU+=LFUr5LrCbLw=x8Bxz8O0ZjN+U=Cu4w@mail.gmail.com>
	<CAFiTN-tyWCqoHzsKzTbk1R6PMO0pC3g-=5=giB644rLjfZkCYA@mail.gmail.com>
	<CAFiTN-sRwLUbVPN7_SsXrZnzvkbB=bWDmU-wyvZD1bmRTYrBmQ@mail.gmail.com>
	<CA+Tgmoa3qzewoh9JvXVm5BEA_qKewK9hfJJhyAZFXYhsx9P-1g@mail.gmail.com>
	<CA+TgmoZ9Rap=NuJLSvw2u=9fibUdB2L_Cs2Wb8FD49vhiXsdpQ@mail.gmail.com>

On Wed, Feb 10, 2021 at 04:56:17PM -0500, Robert Haas wrote:
> Small delta patch with a few other suggested changes attached.

Robert's fixup patch caused the CI to fail, since it 1) was called *.patch;
and, 2) didn't include the previous patches.

This includes a couple proposals of mine as separate patches.

 . psql: Add HIDE_COMPRESSAM for regress testing; I'm proposing this as part of
   0001 (I excluded the reression test changes from 0001 which would've been
   reverted by this patch).
 . Add default_toast_compression GUC with ideas from Robert; I'm proposing
   something like this as part of 0001.  Actually, the full complexity with syscache
   lookups and invalidation aren't needed in 0001, but are needed in the 
   "Custom compression" patch.
 . default --enable-lz4 (this not meant to be merged so you could leave this as
   a separate patch)

I'm not including the whole patch series, since this patch is failing
pg_restore tests:
|Create custom compression methods

-- 
Justin

Attachments:

  [text/x-diff] v24-0001-Built-in-compression-method.patch (116.2K, ../20210214184940.GL1793@telsasoft.com/2-v24-0001-Built-in-compression-method.patch)
  download | inline diff:
From 28b99449da0942f945e3762b86ac977a15076932 Mon Sep 17 00:00:00 2001
From: dilipkumar <dilipbalaut@gmail.com>
Date: Fri, 5 Feb 2021 18:21:47 +0530
Subject: [PATCH v24 1/7] Built-in compression method

Add syntax allowing a compression method to be specified.
As of now there is only 2 option for build-in compression
method (pglz, lz4) which can be set while creating a table
or adding a new column.  No option for altering the
compression method for an existing column.

Dilip Kumar based on the patches from Ildus Kurbangaliev.
Design input from Robert Haas and Tomas Vondra.
Reviewed by Robert Haas, Tomas Vondra, Alexander Korotkov and Justin Pryzby

Discussions:
https://www.postgresql.org/message-id/20171213151818.75a20259@postgrespro.ru
https://www.postgresql.org/message-id/CA%2BTgmoaKDW1Oi9V%3Djc9hOGyf77NbkNEABuqgHD1Cq%3D%3D1QsOcxg%40mail.gmail.com
https://www.postgresql.org/message-id/CA%2BTgmobSDVgUage9qQ5P_%3DF_9jaMkCgyKxUQGtFQU7oN4kX-AA%40mail.gmail.com
https://www.postgresql.org/message-id/20201005160355.byp74sh3ejsv7wrj%40development
https://www.postgresql.org/message-id/CAFiTN-tzTTT2oqWdRGLv1dvvS5MC1W%2BLE%2B3bqWPJUZj4GnHOJg%40mail.gmail.com
---
 configure                                     | 116 ++++++++++
 configure.ac                                  |  17 ++
 contrib/test_decoding/expected/ddl.out        |  50 ++---
 doc/src/sgml/ddl.sgml                         |   3 +
 doc/src/sgml/ref/create_table.sgml            |  25 +++
 src/backend/access/Makefile                   |   2 +-
 src/backend/access/brin/brin_tuple.c          |   5 +-
 src/backend/access/common/detoast.c           | 103 ++++++---
 src/backend/access/common/indextuple.c        |   4 +-
 src/backend/access/common/toast_internals.c   |  63 +++---
 src/backend/access/common/tupdesc.c           |   8 +
 src/backend/access/compression/Makefile       |  17 ++
 src/backend/access/compression/compress_lz4.c | 164 ++++++++++++++
 .../access/compression/compress_pglz.c        | 138 ++++++++++++
 src/backend/access/table/toast_helper.c       |   5 +-
 src/backend/bootstrap/bootstrap.c             |   5 +
 src/backend/catalog/genbki.pl                 |   7 +-
 src/backend/catalog/heap.c                    |   4 +
 src/backend/catalog/index.c                   |   2 +
 src/backend/catalog/toasting.c                |   5 +
 src/backend/commands/amcmds.c                 |  10 +
 src/backend/commands/createas.c               |  14 ++
 src/backend/commands/matview.c                |  14 ++
 src/backend/commands/tablecmds.c              | 111 +++++++++-
 src/backend/executor/nodeModifyTable.c        | 122 +++++++++++
 src/backend/nodes/copyfuncs.c                 |   1 +
 src/backend/nodes/equalfuncs.c                |   1 +
 src/backend/nodes/nodeFuncs.c                 |   2 +
 src/backend/nodes/outfuncs.c                  |   1 +
 src/backend/parser/gram.y                     |  26 ++-
 src/backend/parser/parse_utilcmd.c            |   8 +
 src/backend/utils/adt/pseudotypes.c           |   1 +
 src/backend/utils/adt/varlena.c               |  42 ++++
 src/bin/pg_dump/pg_backup.h                   |   1 +
 src/bin/pg_dump/pg_dump.c                     |  36 +++-
 src/bin/pg_dump/pg_dump.h                     |   1 +
 src/bin/pg_dump/t/002_pg_dump.pl              |  12 +-
 src/bin/psql/describe.c                       |  28 ++-
 src/include/access/compressamapi.h            |  99 +++++++++
 src/include/access/detoast.h                  |   8 +
 src/include/access/toast_helper.h             |   1 +
 src/include/access/toast_internals.h          |  19 +-
 src/include/catalog/pg_am.dat                 |   6 +
 src/include/catalog/pg_am.h                   |   1 +
 src/include/catalog/pg_attribute.h            |   8 +-
 src/include/catalog/pg_proc.dat               |  20 ++
 src/include/catalog/pg_type.dat               |   5 +
 src/include/commands/defrem.h                 |   1 +
 src/include/executor/executor.h               |   4 +-
 src/include/nodes/execnodes.h                 |   6 +
 src/include/nodes/nodes.h                     |   1 +
 src/include/nodes/parsenodes.h                |   2 +
 src/include/parser/kwlist.h                   |   1 +
 src/include/pg_config.h.in                    |   3 +
 src/include/postgres.h                        |  12 +-
 src/test/regress/expected/compression.out     | 201 ++++++++++++++++++
 src/test/regress/expected/compression_1.out   | 189 ++++++++++++++++
 src/test/regress/expected/psql.out            |  68 +++---
 src/test/regress/parallel_schedule            |   2 +-
 src/test/regress/serial_schedule              |   1 +
 src/test/regress/sql/compression.sql          |  85 ++++++++
 src/tools/msvc/Solution.pm                    |   1 +
 src/tools/pgindent/typedefs.list              |   1 +
 63 files changed, 1771 insertions(+), 148 deletions(-)
 create mode 100644 src/backend/access/compression/Makefile
 create mode 100644 src/backend/access/compression/compress_lz4.c
 create mode 100644 src/backend/access/compression/compress_pglz.c
 create mode 100644 src/include/access/compressamapi.h
 create mode 100644 src/test/regress/expected/compression.out
 create mode 100644 src/test/regress/expected/compression_1.out
 create mode 100644 src/test/regress/sql/compression.sql

diff --git a/configure b/configure
index ce9ea36999..0895b2f326 100755
--- a/configure
+++ b/configure
@@ -699,6 +699,7 @@ with_gnu_ld
 LD
 LDFLAGS_SL
 LDFLAGS_EX
+with_lz4
 with_zlib
 with_system_tzdata
 with_libxslt
@@ -864,6 +865,7 @@ with_libxml
 with_libxslt
 with_system_tzdata
 with_zlib
+with_lz4
 with_gnu_ld
 with_ssl
 with_openssl
@@ -1569,6 +1571,7 @@ Optional Packages:
   --with-system-tzdata=DIR
                           use system time zone data in DIR
   --without-zlib          do not use Zlib
+  --with-lz4              build with LZ4 support
   --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
   --with-ssl=LIB          use LIB for SSL/TLS support (openssl)
   --with-openssl          obsolete spelling of --with-ssl=openssl
@@ -8563,6 +8566,39 @@ fi
 
 
 
+#
+# LZ4
+#
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build with LZ4 support" >&5
+$as_echo_n "checking whether to build with LZ4 support... " >&6; }
+
+
+
+# Check whether --with-lz4 was given.
+if test "${with_lz4+set}" = set; then :
+  withval=$with_lz4;
+  case $withval in
+    yes)
+
+$as_echo "#define USE_LZ4 1" >>confdefs.h
+
+      ;;
+    no)
+      :
+      ;;
+    *)
+      as_fn_error $? "no argument expected for --with-lz4 option" "$LINENO" 5
+      ;;
+  esac
+
+else
+  with_lz4=no
+
+fi
+
+
+
+
 #
 # Assignments
 #
@@ -12054,6 +12090,56 @@ fi
 
 fi
 
+if test "$with_lz4" = yes ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for LZ4_compress in -llz4" >&5
+$as_echo_n "checking for LZ4_compress in -llz4... " >&6; }
+if ${ac_cv_lib_lz4_LZ4_compress+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-llz4  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char LZ4_compress ();
+int
+main ()
+{
+return LZ4_compress ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_lz4_LZ4_compress=yes
+else
+  ac_cv_lib_lz4_LZ4_compress=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_lz4_LZ4_compress" >&5
+$as_echo "$ac_cv_lib_lz4_LZ4_compress" >&6; }
+if test "x$ac_cv_lib_lz4_LZ4_compress" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBLZ4 1
+_ACEOF
+
+  LIBS="-llz4 $LIBS"
+
+else
+  as_fn_error $? "library 'lz4' is required for LZ4 support" "$LINENO" 5
+fi
+
+fi
+
 if test "$enable_spinlocks" = yes; then
 
 $as_echo "#define HAVE_SPINLOCKS 1" >>confdefs.h
@@ -13320,6 +13406,36 @@ Use --without-zlib to disable zlib support." "$LINENO" 5
 fi
 
 
+fi
+
+if test "$with_lz4" = yes ; then
+  for ac_header in lz4/lz4.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "lz4/lz4.h" "ac_cv_header_lz4_lz4_h" "$ac_includes_default"
+if test "x$ac_cv_header_lz4_lz4_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LZ4_LZ4_H 1
+_ACEOF
+
+else
+  for ac_header in lz4.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "lz4.h" "ac_cv_header_lz4_h" "$ac_includes_default"
+if test "x$ac_cv_header_lz4_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LZ4_H 1
+_ACEOF
+
+else
+  as_fn_error $? "lz4.h header file is required for LZ4" "$LINENO" 5
+fi
+
+done
+
+fi
+
+done
+
 fi
 
 if test "$with_gssapi" = yes ; then
diff --git a/configure.ac b/configure.ac
index 07da84d401..63940b78a0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -986,6 +986,14 @@ PGAC_ARG_BOOL(with, zlib, yes,
               [do not use Zlib])
 AC_SUBST(with_zlib)
 
+#
+# LZ4
+#
+AC_MSG_CHECKING([whether to build with LZ4 support])
+PGAC_ARG_BOOL(with, lz4, no, [build with LZ4 support],
+              [AC_DEFINE([USE_LZ4], 1, [Define to 1 to build with LZ4 support. (--with-lz4)])])
+AC_SUBST(with_lz4)
+
 #
 # Assignments
 #
@@ -1173,6 +1181,10 @@ failure.  It is possible the compiler isn't looking in the proper directory.
 Use --without-zlib to disable zlib support.])])
 fi
 
+if test "$with_lz4" = yes ; then
+  AC_CHECK_LIB(lz4, LZ4_compress, [], [AC_MSG_ERROR([library 'lz4' is required for LZ4 support])])
+fi
+
 if test "$enable_spinlocks" = yes; then
   AC_DEFINE(HAVE_SPINLOCKS, 1, [Define to 1 if you have spinlocks.])
 else
@@ -1406,6 +1418,11 @@ failure.  It is possible the compiler isn't looking in the proper directory.
 Use --without-zlib to disable zlib support.])])
 fi
 
+if test "$with_lz4" = yes ; then
+  AC_CHECK_HEADERS(lz4/lz4.h, [],
+	[AC_CHECK_HEADERS(lz4.h, [], [AC_MSG_ERROR([lz4.h header file is required for LZ4])])])
+fi
+
 if test "$with_gssapi" = yes ; then
   AC_CHECK_HEADERS(gssapi/gssapi.h, [],
 	[AC_CHECK_HEADERS(gssapi.h, [], [AC_MSG_ERROR([gssapi.h header file is required for GSSAPI])])])
diff --git a/contrib/test_decoding/expected/ddl.out b/contrib/test_decoding/expected/ddl.out
index 4ff0044c78..6ee077678d 100644
--- a/contrib/test_decoding/expected/ddl.out
+++ b/contrib/test_decoding/expected/ddl.out
@@ -438,12 +438,12 @@ CREATE TABLE replication_metadata (
 WITH (user_catalog_table = true)
 ;
 \d+ replication_metadata
-                                                 Table "public.replication_metadata"
-  Column  |  Type   | Collation | Nullable |                     Default                      | Storage  | Stats target | Description 
-----------+---------+-----------+----------+--------------------------------------------------+----------+--------------+-------------
- id       | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |              | 
- relation | name    |           | not null |                                                  | plain    |              | 
- options  | text[]  |           |          |                                                  | extended |              | 
+                                                        Table "public.replication_metadata"
+  Column  |  Type   | Collation | Nullable |                     Default                      | Storage  | Compression | Stats target | Description 
+----------+---------+-----------+----------+--------------------------------------------------+----------+-------------+--------------+-------------
+ id       | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |             |              | 
+ relation | name    |           | not null |                                                  | plain    |             |              | 
+ options  | text[]  |           |          |                                                  | extended | pglz        |              | 
 Indexes:
     "replication_metadata_pkey" PRIMARY KEY, btree (id)
 Options: user_catalog_table=true
@@ -452,12 +452,12 @@ INSERT INTO replication_metadata(relation, options)
 VALUES ('foo', ARRAY['a', 'b']);
 ALTER TABLE replication_metadata RESET (user_catalog_table);
 \d+ replication_metadata
-                                                 Table "public.replication_metadata"
-  Column  |  Type   | Collation | Nullable |                     Default                      | Storage  | Stats target | Description 
-----------+---------+-----------+----------+--------------------------------------------------+----------+--------------+-------------
- id       | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |              | 
- relation | name    |           | not null |                                                  | plain    |              | 
- options  | text[]  |           |          |                                                  | extended |              | 
+                                                        Table "public.replication_metadata"
+  Column  |  Type   | Collation | Nullable |                     Default                      | Storage  | Compression | Stats target | Description 
+----------+---------+-----------+----------+--------------------------------------------------+----------+-------------+--------------+-------------
+ id       | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |             |              | 
+ relation | name    |           | not null |                                                  | plain    |             |              | 
+ options  | text[]  |           |          |                                                  | extended | pglz        |              | 
 Indexes:
     "replication_metadata_pkey" PRIMARY KEY, btree (id)
 
@@ -465,12 +465,12 @@ INSERT INTO replication_metadata(relation, options)
 VALUES ('bar', ARRAY['a', 'b']);
 ALTER TABLE replication_metadata SET (user_catalog_table = true);
 \d+ replication_metadata
-                                                 Table "public.replication_metadata"
-  Column  |  Type   | Collation | Nullable |                     Default                      | Storage  | Stats target | Description 
-----------+---------+-----------+----------+--------------------------------------------------+----------+--------------+-------------
- id       | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |              | 
- relation | name    |           | not null |                                                  | plain    |              | 
- options  | text[]  |           |          |                                                  | extended |              | 
+                                                        Table "public.replication_metadata"
+  Column  |  Type   | Collation | Nullable |                     Default                      | Storage  | Compression | Stats target | Description 
+----------+---------+-----------+----------+--------------------------------------------------+----------+-------------+--------------+-------------
+ id       | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |             |              | 
+ relation | name    |           | not null |                                                  | plain    |             |              | 
+ options  | text[]  |           |          |                                                  | extended | pglz        |              | 
 Indexes:
     "replication_metadata_pkey" PRIMARY KEY, btree (id)
 Options: user_catalog_table=true
@@ -483,13 +483,13 @@ ALTER TABLE replication_metadata ALTER COLUMN rewritemeornot TYPE text;
 ERROR:  cannot rewrite table "replication_metadata" used as a catalog table
 ALTER TABLE replication_metadata SET (user_catalog_table = false);
 \d+ replication_metadata
-                                                    Table "public.replication_metadata"
-     Column     |  Type   | Collation | Nullable |                     Default                      | Storage  | Stats target | Description 
-----------------+---------+-----------+----------+--------------------------------------------------+----------+--------------+-------------
- id             | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |              | 
- relation       | name    |           | not null |                                                  | plain    |              | 
- options        | text[]  |           |          |                                                  | extended |              | 
- rewritemeornot | integer |           |          |                                                  | plain    |              | 
+                                                           Table "public.replication_metadata"
+     Column     |  Type   | Collation | Nullable |                     Default                      | Storage  | Compression | Stats target | Description 
+----------------+---------+-----------+----------+--------------------------------------------------+----------+-------------+--------------+-------------
+ id             | integer |           | not null | nextval('replication_metadata_id_seq'::regclass) | plain    |             |              | 
+ relation       | name    |           | not null |                                                  | plain    |             |              | 
+ options        | text[]  |           |          |                                                  | extended | pglz        |              | 
+ rewritemeornot | integer |           |          |                                                  | plain    |             |              | 
 Indexes:
     "replication_metadata_pkey" PRIMARY KEY, btree (id)
 Options: user_catalog_table=false
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 1e9a4625cc..4d7ed698b9 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,6 +3762,9 @@ CREATE TABLE measurement (
        <productname>PostgreSQL</productname>
        tables (or, possibly, foreign tables).  It is possible to specify a
        tablespace and storage parameters for each partition separately.
+       By default, each column in a partition inherits the compression method
+       from parent table's column, however a different compression method can be
+       set for each partition.
       </para>
 
       <para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 569f4c9da7..51a7a977a5 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -69,6 +69,7 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
   GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( <replaceable>sequence_options</replaceable> ) ] |
   UNIQUE <replaceable class="parameter">index_parameters</replaceable> |
   PRIMARY KEY <replaceable class="parameter">index_parameters</replaceable> |
+  COMPRESSION <replaceable class="parameter">compression_method</replaceable> |
   REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ]
     [ ON DELETE <replaceable class="parameter">referential_action</replaceable> ] [ ON UPDATE <replaceable class="parameter">referential_action</replaceable> ] }
 [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
@@ -605,6 +606,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
         </listitem>
        </varlistentry>
 
+       <varlistentry>
+        <term><literal>INCLUDING COMPRESSION</literal></term>
+        <listitem>
+         <para>
+          Compression method of the columns will be copied.  The default
+          behavior is to exclude compression methods, resulting in the columns
+          having the default compression method.
+         </para>
+        </listitem>
+       </varlistentry>
+
        <varlistentry>
         <term><literal>INCLUDING CONSTRAINTS</literal></term>
         <listitem>
@@ -981,6 +993,19 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
+    <listitem>
+     <para>
+      This sets the compression method for a column.  The supported compression
+      methods are <literal>pglz</literal> and <literal>lz4</literal>.
+      <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
+      was used when building <productname>PostgreSQL</productname>. The default
+      is <literal>pglz</literal>.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry id="sql-createtable-exclude">
     <term><literal>EXCLUDE [ USING <replaceable class="parameter">index_method</replaceable> ] ( <replaceable class="parameter">exclude_element</replaceable> WITH <replaceable class="parameter">operator</replaceable> [, ... ] ) <replaceable class="parameter">index_parameters</replaceable> [ WHERE ( <replaceable class="parameter">predicate</replaceable> ) ]</literal></term>
     <listitem>
diff --git a/src/backend/access/Makefile b/src/backend/access/Makefile
index 0880e0a8bb..ba08bdd63e 100644
--- a/src/backend/access/Makefile
+++ b/src/backend/access/Makefile
@@ -8,7 +8,7 @@ subdir = src/backend/access
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
-SUBDIRS	    = brin common gin gist hash heap index nbtree rmgrdesc spgist \
+SUBDIRS	    = brin common compression gin gist hash heap index nbtree rmgrdesc spgist \
 			  table tablesample transam
 
 include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/access/brin/brin_tuple.c b/src/backend/access/brin/brin_tuple.c
index a7eb1c9473..0ab5712c71 100644
--- a/src/backend/access/brin/brin_tuple.c
+++ b/src/backend/access/brin/brin_tuple.c
@@ -213,7 +213,10 @@ brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple,
 				(atttype->typstorage == TYPSTORAGE_EXTENDED ||
 				 atttype->typstorage == TYPSTORAGE_MAIN))
 			{
-				Datum		cvalue = toast_compress_datum(value);
+				Form_pg_attribute att = TupleDescAttr(brdesc->bd_tupdesc,
+													  keyno);
+				Datum		cvalue = toast_compress_datum(value,
+														  att->attcompression);
 
 				if (DatumGetPointer(cvalue) != NULL)
 				{
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index d1cdbaf648..b78d49167b 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -13,6 +13,7 @@
 
 #include "postgres.h"
 
+#include "access/compressamapi.h"
 #include "access/detoast.h"
 #include "access/table.h"
 #include "access/tableam.h"
@@ -457,28 +458,78 @@ toast_fetch_datum_slice(struct varlena *attr, int32 sliceoffset,
 }
 
 /* ----------
- * toast_decompress_datum -
+ * toast_get_compression_oid -
  *
- * Decompress a compressed version of a varlena datum
+ * Returns the Oid of the compression method stored in the compressed data.  If
+ * the varlena is not compressed then returns InvalidOid.
  */
-static struct varlena *
-toast_decompress_datum(struct varlena *attr)
+Oid
+toast_get_compression_oid(struct varlena *attr)
 {
-	struct varlena *result;
+	if (VARATT_IS_EXTERNAL_ONDISK(attr))
+	{
+		struct varatt_external toast_pointer;
+
+		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+		/* fast path for non-compressed external datums */
+		if (!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
+			return InvalidOid;
+
+		/*
+		 * Just fetch the toast compress header to know the compression method
+		 * in the compressed data.
+		 */
+		attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
+	}
+	else if (!VARATT_IS_COMPRESSED(attr))
+		return InvalidOid;
+
+	return CompressionIdToOid(TOAST_COMPRESS_METHOD(attr));
+}
+
+/* ----------
+ * toast_get_compression_handler - get the compression handler routines
+ *
+ * helper function for toast_decompress_datum and toast_decompress_datum_slice
+ */
+static inline const CompressionAmRoutine *
+toast_get_compression_handler(struct varlena *attr)
+{
+	const CompressionAmRoutine *cmroutine;
+	CompressionId cmid;
 
 	Assert(VARATT_IS_COMPRESSED(attr));
 
-	result = (struct varlena *)
-		palloc(TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
-	SET_VARSIZE(result, TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
+	cmid = TOAST_COMPRESS_METHOD(attr);
 
-	if (pglz_decompress(TOAST_COMPRESS_RAWDATA(attr),
-						TOAST_COMPRESS_SIZE(attr),
-						VARDATA(result),
-						TOAST_COMPRESS_RAWSIZE(attr), true) < 0)
-		elog(ERROR, "compressed data is corrupted");
+	/* Get the handler routines for the compression method */
+	switch (cmid)
+	{
+		case PGLZ_COMPRESSION_ID:
+			cmroutine = &pglz_compress_methods;
+			break;
+		case LZ4_COMPRESSION_ID:
+			cmroutine = &lz4_compress_methods;
+			break;
+		default:
+			elog(ERROR, "invalid compression method id %d", cmid);
+	}
 
-	return result;
+	return cmroutine;
+}
+
+/* ----------
+ * toast_decompress_datum -
+ *
+ * Decompress a compressed version of a varlena datum
+ */
+static struct varlena *
+toast_decompress_datum(struct varlena *attr)
+{
+	const CompressionAmRoutine *cmroutine = toast_get_compression_handler(attr);
+
+	return cmroutine->datum_decompress(attr);
 }
 
 
@@ -492,22 +543,16 @@ toast_decompress_datum(struct varlena *attr)
 static struct varlena *
 toast_decompress_datum_slice(struct varlena *attr, int32 slicelength)
 {
-	struct varlena *result;
-	int32		rawsize;
-
-	Assert(VARATT_IS_COMPRESSED(attr));
-
-	result = (struct varlena *) palloc(slicelength + VARHDRSZ);
-
-	rawsize = pglz_decompress(TOAST_COMPRESS_RAWDATA(attr),
-							  VARSIZE(attr) - TOAST_COMPRESS_HDRSZ,
-							  VARDATA(result),
-							  slicelength, false);
-	if (rawsize < 0)
-		elog(ERROR, "compressed data is corrupted");
+	const CompressionAmRoutine *cmroutine = toast_get_compression_handler(attr);
 
-	SET_VARSIZE(result, rawsize + VARHDRSZ);
-	return result;
+	/*
+	 * If the handler supports the slice decompression then decompress the
+	 * slice otherwise decompress complete data.
+	 */
+	if (cmroutine->datum_decompress_slice)
+		return cmroutine->datum_decompress_slice(attr, slicelength);
+	else
+		return cmroutine->datum_decompress(attr);
 }
 
 /* ----------
diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
index b72a138497..1d43d5d2ff 100644
--- a/src/backend/access/common/indextuple.c
+++ b/src/backend/access/common/indextuple.c
@@ -16,6 +16,7 @@
 
 #include "postgres.h"
 
+#include "access/compressamapi.h"
 #include "access/detoast.h"
 #include "access/heaptoast.h"
 #include "access/htup_details.h"
@@ -103,7 +104,8 @@ index_form_tuple(TupleDesc tupleDescriptor,
 			(att->attstorage == TYPSTORAGE_EXTENDED ||
 			 att->attstorage == TYPSTORAGE_MAIN))
 		{
-			Datum		cvalue = toast_compress_datum(untoasted_values[i]);
+			Datum		cvalue = toast_compress_datum(untoasted_values[i],
+													  att->attcompression);
 
 			if (DatumGetPointer(cvalue) != NULL)
 			{
diff --git a/src/backend/access/common/toast_internals.c b/src/backend/access/common/toast_internals.c
index 9b9da0f41b..b04c5a5eb8 100644
--- a/src/backend/access/common/toast_internals.c
+++ b/src/backend/access/common/toast_internals.c
@@ -44,46 +44,51 @@ static bool toastid_valueid_exists(Oid toastrelid, Oid valueid);
  * ----------
  */
 Datum
-toast_compress_datum(Datum value)
+toast_compress_datum(Datum value, Oid cmoid)
 {
-	struct varlena *tmp;
-	int32		valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
-	int32		len;
+	struct varlena *tmp = NULL;
+	int32		valsize;
+	const CompressionAmRoutine *cmroutine = NULL;
 
 	Assert(!VARATT_IS_EXTERNAL(DatumGetPointer(value)));
 	Assert(!VARATT_IS_COMPRESSED(DatumGetPointer(value)));
 
-	/*
-	 * No point in wasting a palloc cycle if value size is out of the allowed
-	 * range for compression
-	 */
-	if (valsize < PGLZ_strategy_default->min_input_size ||
-		valsize > PGLZ_strategy_default->max_input_size)
-		return PointerGetDatum(NULL);
+	Assert(OidIsValid(cmoid));
+
+	/* Get the handler routines for the compression method */
+	switch (cmoid)
+	{
+		case PGLZ_COMPRESSION_AM_OID:
+			cmroutine = &pglz_compress_methods;
+			break;
+		case LZ4_COMPRESSION_AM_OID:
+			cmroutine = &lz4_compress_methods;
+			break;
+		default:
+			elog(ERROR, "Invalid compression method oid %u", cmoid);
+	}
 
-	tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize) +
-									TOAST_COMPRESS_HDRSZ);
+	/* Call the actual compression function */
+	tmp = cmroutine->datum_compress((const struct varlena *) value);
+	if (!tmp)
+		return PointerGetDatum(NULL);
 
 	/*
-	 * We recheck the actual size even if pglz_compress() reports success,
-	 * because it might be satisfied with having saved as little as one byte
-	 * in the compressed data --- which could turn into a net loss once you
-	 * consider header and alignment padding.  Worst case, the compressed
-	 * format might require three padding bytes (plus header, which is
-	 * included in VARSIZE(tmp)), whereas the uncompressed format would take
-	 * only one header byte and no padding if the value is short enough.  So
-	 * we insist on a savings of more than 2 bytes to ensure we have a gain.
+	 * We recheck the actual size even if compression reports success, because
+	 * it might be satisfied with having saved as little as one byte in the
+	 * compressed data --- which could turn into a net loss once you consider
+	 * header and alignment padding.  Worst case, the compressed format might
+	 * require three padding bytes (plus header, which is included in
+	 * VARSIZE(tmp)), whereas the uncompressed format would take only one
+	 * header byte and no padding if the value is short enough.  So we insist
+	 * on a savings of more than 2 bytes to ensure we have a gain.
 	 */
-	len = pglz_compress(VARDATA_ANY(DatumGetPointer(value)),
-						valsize,
-						TOAST_COMPRESS_RAWDATA(tmp),
-						PGLZ_strategy_default);
-	if (len >= 0 &&
-		len + TOAST_COMPRESS_HDRSZ < valsize - 2)
+	valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
+
+	if (VARSIZE(tmp) < valsize - 2)
 	{
-		TOAST_COMPRESS_SET_RAWSIZE(tmp, valsize);
-		SET_VARSIZE_COMPRESSED(tmp, len + TOAST_COMPRESS_HDRSZ);
 		/* successful compression */
+		TOAST_COMPRESS_SET_SIZE_AND_METHOD(tmp, valsize, CompressionOidToId(cmoid));
 		return PointerGetDatum(tmp);
 	}
 	else
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index 902f59440c..ca26fab487 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -19,6 +19,7 @@
 
 #include "postgres.h"
 
+#include "access/compressamapi.h"
 #include "access/htup_details.h"
 #include "access/tupdesc_details.h"
 #include "catalog/pg_collation.h"
@@ -470,6 +471,8 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
 			return false;
 		if (attr1->attcollation != attr2->attcollation)
 			return false;
+		if (attr1->attcompression != attr2->attcompression)
+			return false;
 		/* attacl, attoptions and attfdwoptions are not even present... */
 	}
 
@@ -664,6 +667,11 @@ TupleDescInitEntry(TupleDesc desc,
 	att->attstorage = typeForm->typstorage;
 	att->attcollation = typeForm->typcollation;
 
+	if (IsStorageCompressible(typeForm->typstorage))
+		att->attcompression = DefaultCompressionOid;
+	else
+		att->attcompression = InvalidOid;
+
 	ReleaseSysCache(tuple);
 }
 
diff --git a/src/backend/access/compression/Makefile b/src/backend/access/compression/Makefile
new file mode 100644
index 0000000000..779f54e785
--- /dev/null
+++ b/src/backend/access/compression/Makefile
@@ -0,0 +1,17 @@
+#-------------------------------------------------------------------------
+#
+# Makefile--
+#    Makefile for access/compression
+#
+# IDENTIFICATION
+#    src/backend/access/compression/Makefile
+#
+#-------------------------------------------------------------------------
+
+subdir = src/backend/access/compression
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+
+OBJS = compress_pglz.o compress_lz4.o
+
+include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
new file mode 100644
index 0000000000..1856cf7df7
--- /dev/null
+++ b/src/backend/access/compression/compress_lz4.c
@@ -0,0 +1,164 @@
+/*-------------------------------------------------------------------------
+ *
+ * compress_lz4.c
+ *		lz4 compression method.
+ *
+ * Portions Copyright (c) 2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/compression/compress_lz4.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#ifdef HAVE_LIBLZ4
+#include <lz4.h>
+#endif
+
+#include "access/compressamapi.h"
+#include "fmgr.h"
+#include "utils/builtins.h"
+
+/*
+ * lz4_cmcompress - compression routine for lz4 compression method
+ *
+ * Compresses source into dest using the default strategy. Returns the
+ * compressed varlena, or NULL if compression fails.
+ */
+static struct varlena *
+lz4_cmcompress(const struct varlena *value)
+{
+#ifndef HAVE_LIBLZ4
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("not built with lz4 support")));
+#else
+	int32		valsize;
+	int32		len;
+	int32		max_size;
+	struct varlena *tmp = NULL;
+
+	valsize = VARSIZE_ANY_EXHDR(value);
+
+	/*
+	 * Get maximum size of the compressed data that lz4 compression may output
+	 * and allocate the memory for holding the compressed data and the header.
+	 */
+	max_size = LZ4_compressBound(valsize);
+	tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
+
+	len = LZ4_compress_default(VARDATA_ANY(value),
+							   (char *) tmp + VARHDRSZ_COMPRESS,
+							   valsize, max_size);
+	if (len <= 0)
+		elog(ERROR, "could not compress data with lz4");
+
+	/* data is incompressible so just free the memory and return NULL */
+	if (len > valsize)
+	{
+		pfree(tmp);
+		return NULL;
+	}
+
+	SET_VARSIZE_COMPRESSED(tmp, len + VARHDRSZ_COMPRESS);
+
+	return tmp;
+#endif
+}
+
+/*
+ * lz4_cmdecompress - decompression routine for lz4 compression method
+ *
+ * Returns the decompressed varlena.
+ */
+static struct varlena *
+lz4_cmdecompress(const struct varlena *value)
+{
+#ifndef HAVE_LIBLZ4
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("not built with lz4 support")));
+#else
+	int32		rawsize;
+	struct varlena *result;
+
+	/* allocate memory for holding the uncompressed data */
+	result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
+
+	/* decompress data using lz4 routine */
+	rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
+								  VARDATA(result),
+								  VARSIZE(value) - VARHDRSZ_COMPRESS,
+								  VARRAWSIZE_4B_C(value));
+	if (rawsize < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg_internal("compressed lz4 data is corrupt")));
+
+
+	SET_VARSIZE(result, rawsize + VARHDRSZ);
+
+	return result;
+#endif
+}
+
+/*
+ * lz4_cmdecompress_slice - slice decompression routine for lz4 compression
+ *
+ * Decompresses part of the data. Returns the decompressed varlena.
+ */
+static struct varlena *
+lz4_cmdecompress_slice(const struct varlena *value, int32 slicelength)
+{
+#ifndef HAVE_LIBLZ4
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("not built with lz4 support")));
+#else
+	int32		rawsize;
+	struct varlena *result;
+
+	/* allocate memory for holding the uncompressed data */
+	result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
+
+	/* decompress partial data using lz4 routine */
+	rawsize = LZ4_decompress_safe_partial((char *) value + VARHDRSZ_COMPRESS,
+										  VARDATA(result),
+										  VARSIZE(value) - VARHDRSZ_COMPRESS,
+										  slicelength,
+										  VARRAWSIZE_4B_C(value));
+	if (rawsize < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg_internal("compressed lz4 data is corrupt")));
+
+	SET_VARSIZE(result, rawsize + VARHDRSZ);
+
+	return result;
+#endif
+}
+
+/* ------------------------------------------------------------------------
+ * Definition of the lz4 compression access method.
+ * ------------------------------------------------------------------------
+ */
+const CompressionAmRoutine lz4_compress_methods = {
+	.type = T_CompressionAmRoutine,
+	.datum_compress = lz4_cmcompress,
+	.datum_decompress = lz4_cmdecompress,
+	.datum_decompress_slice = lz4_cmdecompress_slice
+};
+
+/* lz4 compression handler function */
+Datum
+lz4handler(PG_FUNCTION_ARGS)
+{
+#ifndef HAVE_LIBLZ4
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("not built with lz4 support")));
+#else
+	PG_RETURN_POINTER(&lz4_compress_methods);
+#endif
+}
diff --git a/src/backend/access/compression/compress_pglz.c b/src/backend/access/compression/compress_pglz.c
new file mode 100644
index 0000000000..8a4bf427cf
--- /dev/null
+++ b/src/backend/access/compression/compress_pglz.c
@@ -0,0 +1,138 @@
+/*-------------------------------------------------------------------------
+ *
+ * compress_pglz.c
+ *	  pglz compression method
+ *
+ * Portions Copyright (c) 2021, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/compression/compress_pglz.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/compressamapi.h"
+#include "common/pg_lzcompress.h"
+
+#include "fmgr.h"
+#include "utils/builtins.h"
+
+/*
+ * pglz_cmcompress - compression routine for pglz compression method
+ *
+ * Compresses source into dest using the default strategy. Returns the
+ * compressed varlena, or NULL if compression fails.
+ */
+static struct varlena *
+pglz_cmcompress(const struct varlena *value)
+{
+	int32		valsize,
+				len;
+	struct varlena *tmp = NULL;
+
+	valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
+
+	/*
+	 * No point in wasting a palloc cycle if value size is outside the allowed
+	 * range for compression.
+	 */
+	if (valsize < PGLZ_strategy_default->min_input_size ||
+		valsize > PGLZ_strategy_default->max_input_size)
+		return NULL;
+
+	/*
+	 * Get maximum size of the compressed data that pglz compression may output
+	 * and allocate the memory for holding the compressed data and the header.
+	 */
+	tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize) +
+									VARHDRSZ_COMPRESS);
+
+	len = pglz_compress(VARDATA_ANY(value),
+						valsize,
+						(char *) tmp + VARHDRSZ_COMPRESS,
+						NULL);
+	if (len < 0)
+	{
+		pfree(tmp);
+		return NULL;
+	}
+
+	SET_VARSIZE_COMPRESSED(tmp, len + VARHDRSZ_COMPRESS);
+
+	return tmp;
+}
+
+/*
+ * pglz_cmdecompress - decompression routine for pglz compression method
+ *
+ * Returns the decompressed varlena.
+ */
+static struct varlena *
+pglz_cmdecompress(const struct varlena *value)
+{
+	struct varlena *result;
+	int32		rawsize;
+
+	result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
+
+	rawsize = pglz_decompress((char *) value + VARHDRSZ_COMPRESS,
+							  VARSIZE(value) - VARHDRSZ_COMPRESS,
+							  VARDATA(result),
+							  VARRAWSIZE_4B_C(value), true);
+	if (rawsize < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg_internal("compressed pglz data is corrupt")));
+
+	SET_VARSIZE(result, rawsize + VARHDRSZ);
+
+	return result;
+}
+
+/*
+ * pglz_decompress - slice decompression routine for pglz compression method
+ *
+ * Decompresses part of the data. Returns the decompressed varlena.
+ */
+static struct varlena *
+pglz_cmdecompress_slice(const struct varlena *value,
+						int32 slicelength)
+{
+	struct varlena *result;
+	int32		rawsize;
+
+	result = (struct varlena *) palloc(slicelength + VARHDRSZ);
+
+	rawsize = pglz_decompress((char *) value + VARHDRSZ_COMPRESS,
+							  VARSIZE(value) - VARHDRSZ_COMPRESS,
+							  VARDATA(result),
+							  slicelength, false);
+	if (rawsize < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_CORRUPTED),
+				 errmsg_internal("compressed pglz data is corrupt")));
+
+	SET_VARSIZE(result, rawsize + VARHDRSZ);
+
+	return result;
+}
+
+/* ------------------------------------------------------------------------
+ * Definition of the pglz compression access method.
+ * ------------------------------------------------------------------------
+ */
+const CompressionAmRoutine pglz_compress_methods = {
+	.type = T_CompressionAmRoutine,
+	.datum_compress = pglz_cmcompress,
+	.datum_decompress = pglz_cmdecompress,
+	.datum_decompress_slice = pglz_cmdecompress_slice
+};
+
+/* pglz compression handler function */
+Datum
+pglzhandler(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_POINTER(&pglz_compress_methods);
+}
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index fb36151ce5..53f78f9c3e 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -54,6 +54,7 @@ toast_tuple_init(ToastTupleContext *ttc)
 
 		ttc->ttc_attr[i].tai_colflags = 0;
 		ttc->ttc_attr[i].tai_oldexternal = NULL;
+		ttc->ttc_attr[i].tai_compression = att->attcompression;
 
 		if (ttc->ttc_oldvalues != NULL)
 		{
@@ -226,9 +227,11 @@ void
 toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 {
 	Datum	   *value = &ttc->ttc_values[attribute];
-	Datum		new_value = toast_compress_datum(*value);
+	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
 
+	new_value = toast_compress_datum(*value, attr->tai_compression);
+
 	if (DatumGetPointer(new_value) != NULL)
 	{
 		/* successful compression */
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 6f615e6622..9b451eaa71 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -17,6 +17,7 @@
 #include <unistd.h>
 #include <signal.h>
 
+#include "access/compressamapi.h"
 #include "access/genam.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
@@ -731,6 +732,10 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 	attrtypes[attnum]->attcacheoff = -1;
 	attrtypes[attnum]->atttypmod = -1;
 	attrtypes[attnum]->attislocal = true;
+	if (IsStorageCompressible(attrtypes[attnum]->attstorage))
+		attrtypes[attnum]->attcompression = DefaultCompressionOid;
+	else
+		attrtypes[attnum]->attcompression = InvalidOid;
 
 	if (nullness == BOOTCOL_NULL_FORCE_NOT_NULL)
 	{
diff --git a/src/backend/catalog/genbki.pl b/src/backend/catalog/genbki.pl
index b159958112..f5bb37b972 100644
--- a/src/backend/catalog/genbki.pl
+++ b/src/backend/catalog/genbki.pl
@@ -187,7 +187,9 @@ my $GenbkiNextOid = $FirstGenbkiObjectId;
 my $C_COLLATION_OID =
   Catalog::FindDefinedSymbolFromData($catalog_data{pg_collation},
 	'C_COLLATION_OID');
-
+my $PGLZ_COMPRESSION_AM_OID =
+  Catalog::FindDefinedSymbolFromData($catalog_data{pg_am},
+	'PGLZ_COMPRESSION_AM_OID');
 
 # Fill in pg_class.relnatts by looking at the referenced catalog's schema.
 # This is ugly but there's no better place; Catalog::AddDefaultValues
@@ -906,6 +908,9 @@ sub morph_row_for_pgattr
 	$row->{attcollation} =
 	  $type->{typcollation} ne '0' ? $C_COLLATION_OID : 0;
 
+	$row->{attcompression} =
+	  $type->{typstorage} ne 'p' && $type->{typstorage} ne 'e' ? $PGLZ_COMPRESSION_AM_OID : 0;
+
 	if (defined $attr->{forcenotnull})
 	{
 		$row->{attnotnull} = 't';
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 9abc4a1f55..b53b6b50e6 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -29,6 +29,7 @@
  */
 #include "postgres.h"
 
+#include "access/compressamapi.h"
 #include "access/genam.h"
 #include "access/htup_details.h"
 #include "access/multixact.h"
@@ -789,6 +790,7 @@ InsertPgAttributeTuples(Relation pg_attribute_rel,
 		slot[slotCount]->tts_values[Anum_pg_attribute_attislocal - 1] = BoolGetDatum(attrs->attislocal);
 		slot[slotCount]->tts_values[Anum_pg_attribute_attinhcount - 1] = Int32GetDatum(attrs->attinhcount);
 		slot[slotCount]->tts_values[Anum_pg_attribute_attcollation - 1] = ObjectIdGetDatum(attrs->attcollation);
+		slot[slotCount]->tts_values[Anum_pg_attribute_attcompression - 1] = CharGetDatum(attrs->attcompression);
 		if (attoptions && attoptions[natts] != (Datum) 0)
 			slot[slotCount]->tts_values[Anum_pg_attribute_attoptions - 1] = attoptions[natts];
 		else
@@ -1715,6 +1717,8 @@ RemoveAttributeById(Oid relid, AttrNumber attnum)
 		/* Unset this so no one tries to look up the generation expression */
 		attStruct->attgenerated = '\0';
 
+		attStruct->attcompression = InvalidOid;
+
 		/*
 		 * Change the column name to something that isn't likely to conflict
 		 */
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 1514937748..d1d6bdf470 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -24,6 +24,7 @@
 #include <unistd.h>
 
 #include "access/amapi.h"
+#include "access/compressamapi.h"
 #include "access/heapam.h"
 #include "access/multixact.h"
 #include "access/reloptions.h"
@@ -348,6 +349,7 @@ ConstructTupleDescriptor(Relation heapRelation,
 			to->attbyval = from->attbyval;
 			to->attstorage = from->attstorage;
 			to->attalign = from->attalign;
+			to->attcompression = from->attcompression;
 		}
 		else
 		{
diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c
index d7b806020d..a549481557 100644
--- a/src/backend/catalog/toasting.c
+++ b/src/backend/catalog/toasting.c
@@ -220,6 +220,11 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
 	TupleDescAttr(tupdesc, 1)->attstorage = TYPSTORAGE_PLAIN;
 	TupleDescAttr(tupdesc, 2)->attstorage = TYPSTORAGE_PLAIN;
 
+	/* Toast field should not be compressed */
+	TupleDescAttr(tupdesc, 0)->attcompression = InvalidOid;
+	TupleDescAttr(tupdesc, 1)->attcompression = InvalidOid;
+	TupleDescAttr(tupdesc, 2)->attcompression = InvalidOid;
+
 	/*
 	 * Toast tables for regular relations go in pg_toast; those for temp
 	 * relations go into the per-backend temp-toast-table namespace.
diff --git a/src/backend/commands/amcmds.c b/src/backend/commands/amcmds.c
index eff9535ed0..3ad4a61739 100644
--- a/src/backend/commands/amcmds.c
+++ b/src/backend/commands/amcmds.c
@@ -175,6 +175,16 @@ get_table_am_oid(const char *amname, bool missing_ok)
 	return get_am_type_oid(amname, AMTYPE_TABLE, missing_ok);
 }
 
+/*
+ * get_compression_am_oid - given an access method name, look up its OID
+ *		and verify it corresponds to an compression AM.
+ */
+Oid
+get_compression_am_oid(const char *amname, bool missing_ok)
+{
+	return get_am_type_oid(amname, AMTYPE_COMPRESSION, missing_ok);
+}
+
 /*
  * get_am_oid - given an access method name, look up its OID.
  *		The type is not checked.
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index dce882012e..1d17dc0d6b 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -61,6 +61,7 @@ typedef struct
 	CommandId	output_cid;		/* cmin to insert in output tuples */
 	int			ti_options;		/* table_tuple_insert performance options */
 	BulkInsertState bistate;	/* bulk insert state */
+	TupleTableSlot *decompress_tuple_slot;	/* to hold the decompress tuple */
 } DR_intorel;
 
 /* utility functions for CTAS definition creation */
@@ -581,6 +582,15 @@ intorel_receive(TupleTableSlot *slot, DestReceiver *self)
 	/* Nothing to insert if WITH NO DATA is specified. */
 	if (!myState->into->skipData)
 	{
+		/*
+		 * Compare the compression method of the compressed attribute in the
+		 * source tuple with target attribute and if those are different then
+		 * decompress those attributes.
+		 */
+		slot = CompareCompressionMethodAndDecompress(slot,
+													 &myState->decompress_tuple_slot,
+													 myState->rel->rd_att);
+
 		/*
 		 * Note that the input slot might not be of the type of the target
 		 * relation. That's supported by table_tuple_insert(), but slightly
@@ -619,6 +629,10 @@ intorel_shutdown(DestReceiver *self)
 	/* close rel, but keep lock until commit */
 	table_close(myState->rel, NoLock);
 	myState->rel = NULL;
+
+	/* release the slot used for decompressing the tuple */
+	if (myState->decompress_tuple_slot)
+		ExecDropSingleTupleTableSlot(myState->decompress_tuple_slot);
 }
 
 /*
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index c5c25ce11d..713fc3fceb 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -56,6 +56,7 @@ typedef struct
 	CommandId	output_cid;		/* cmin to insert in output tuples */
 	int			ti_options;		/* table_tuple_insert performance options */
 	BulkInsertState bistate;	/* bulk insert state */
+	TupleTableSlot *decompress_tuple_slot;	/* to hold the decompress tuple */
 } DR_transientrel;
 
 static int	matview_maintenance_depth = 0;
@@ -486,6 +487,15 @@ transientrel_receive(TupleTableSlot *slot, DestReceiver *self)
 {
 	DR_transientrel *myState = (DR_transientrel *) self;
 
+	/*
+	 * Compare the compression method of the compressed attribute in the
+	 * source tuple with target attribute and if those are different then
+	 * decompress those attributes.
+	 */
+	slot = CompareCompressionMethodAndDecompress(slot,
+												 &myState->decompress_tuple_slot,
+												 myState->transientrel->rd_att);
+
 	/*
 	 * Note that the input slot might not be of the type of the target
 	 * relation. That's supported by table_tuple_insert(), but slightly less
@@ -521,6 +531,10 @@ transientrel_shutdown(DestReceiver *self)
 	/* close transientrel, but keep lock until commit */
 	table_close(myState->transientrel, NoLock);
 	myState->transientrel = NULL;
+
+	/* release the slot used for decompressing the tuple */
+	if (myState->decompress_tuple_slot)
+		ExecDropSingleTupleTableSlot(myState->decompress_tuple_slot);
 }
 
 /*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 420991e315..dd81d5bf4e 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -15,6 +15,7 @@
 #include "postgres.h"
 
 #include "access/attmap.h"
+#include "access/compressamapi.h"
 #include "access/genam.h"
 #include "access/heapam.h"
 #include "access/heapam_xlog.h"
@@ -559,7 +560,7 @@ static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx,
 static List *GetParentedForeignKeyRefs(Relation partition);
 static void ATDetachCheckNoForeignKeyRefs(Relation partition);
 static void ATExecAlterCollationRefreshVersion(Relation rel, List *coll);
-
+static Oid GetAttributeCompression(Form_pg_attribute att, char *compression);
 
 /* ----------------------------------------------------------------
  *		DefineRelation
@@ -853,6 +854,18 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 
 		if (colDef->generated)
 			attr->attgenerated = colDef->generated;
+
+		/*
+		 * lookup attribute's compression method and store its Oid in the
+		 * attr->attcompression.
+		 */
+		if (relkind == RELKIND_RELATION ||
+			relkind == RELKIND_PARTITIONED_TABLE ||
+			relkind == RELKIND_MATVIEW)
+			attr->attcompression =
+				GetAttributeCompression(attr, colDef->compression);
+		else
+			attr->attcompression = InvalidOid;
 	}
 
 	/*
@@ -2397,6 +2410,21 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
 									   storage_name(def->storage),
 									   storage_name(attribute->attstorage))));
 
+				/* Copy/check compression parameter */
+				if (OidIsValid(attribute->attcompression))
+				{
+					char *compression = get_am_name(attribute->attcompression);
+
+					if (!def->compression)
+						def->compression = compression;
+					else if (strcmp(def->compression, compression) != 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_DATATYPE_MISMATCH),
+								 errmsg("column \"%s\" has a compression method conflict",
+										attributeName),
+								 errdetail("%s versus %s", def->compression, compression)));
+				}
+
 				def->inhcount++;
 				/* Merge of NOT NULL constraints = OR 'em together */
 				def->is_not_null |= attribute->attnotnull;
@@ -2431,6 +2459,7 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
 				def->collOid = attribute->attcollation;
 				def->constraints = NIL;
 				def->location = -1;
+				def->compression = get_am_name(attribute->attcompression);
 				inhSchema = lappend(inhSchema, def);
 				newattmap->attnums[parent_attno - 1] = ++child_attno;
 			}
@@ -2676,6 +2705,19 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
 									   storage_name(def->storage),
 									   storage_name(newdef->storage))));
 
+				/* Copy compression parameter */
+				if (!def->compression)
+					def->compression = newdef->compression;
+				else if (newdef->compression)
+				{
+					if (strcmp(def->compression, newdef->compression))
+						ereport(ERROR,
+								(errcode(ERRCODE_DATATYPE_MISMATCH),
+								 errmsg("column \"%s\" has a compression method conflict",
+										attributeName),
+								 errdetail("%s versus %s", def->compression, newdef->compression)));
+				}
+
 				/* Mark the column as locally defined */
 				def->is_local = true;
 				/* Merge of NOT NULL constraints = OR 'em together */
@@ -6341,6 +6383,18 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	attribute.attislocal = colDef->is_local;
 	attribute.attinhcount = colDef->inhcount;
 	attribute.attcollation = collOid;
+
+	/*
+	 * lookup attribute's compression method and store its Oid in the
+	 * attr->attcompression.
+	 */
+	if (rel->rd_rel->relkind == RELKIND_RELATION ||
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+		attribute.attcompression = GetAttributeCompression(&attribute,
+														   colDef->compression);
+	else
+		attribute.attcompression = InvalidOid;
+
 	/* attribute.attacl is handled by InsertPgAttributeTuples() */
 
 	ReleaseSysCache(typeTuple);
@@ -11860,6 +11914,22 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 
 	ReleaseSysCache(typeTuple);
 
+	/* Setup attribute compression */
+	if (rel->rd_rel->relkind == RELKIND_RELATION ||
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		/*
+		 * InvalidOid for the plain/external storage otherwise default
+		 * compression id.
+		 */
+		if (!IsStorageCompressible(tform->typstorage))
+			attTup->attcompression = InvalidOid;
+		else if (!OidIsValid(attTup->attcompression))
+			attTup->attcompression = DefaultCompressionOid;
+	}
+	else
+		attTup->attcompression = InvalidOid;
+
 	CatalogTupleUpdate(attrelation, &heapTup->t_self, heapTup);
 
 	table_close(attrelation, RowExclusiveLock);
@@ -17665,3 +17735,42 @@ ATExecAlterCollationRefreshVersion(Relation rel, List *coll)
 	index_update_collation_versions(rel->rd_id, get_collation_oid(coll, false));
 	CacheInvalidateRelcache(rel);
 }
+
+/*
+ * resolve column compression specification to an OID.
+ */
+static Oid
+GetAttributeCompression(Form_pg_attribute att, char *compression)
+{
+	char		typstorage = get_typstorage(att->atttypid);
+	Oid			amoid;
+
+	/*
+	 * No compression for the plain/external storage, refer comments atop
+	 * attcompression parameter in pg_attribute.h
+	 */
+	if (!IsStorageCompressible(typstorage))
+	{
+		if (compression == NULL)
+			return InvalidOid;
+
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("column data type %s does not support compression",
+						format_type_be(att->atttypid))));
+	}
+
+	/* fallback to default compression if it's not specified */
+	if (compression == NULL)
+		return DefaultCompressionOid;
+
+	amoid = get_compression_am_oid(compression, false);
+
+#ifndef HAVE_LIBLZ4
+	if (amoid == LZ4_COMPRESSION_AM_OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("not built with lz4 support")));
+#endif
+	return amoid;
+}
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index 2993ba43e3..f77deee399 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -37,6 +37,8 @@
 
 #include "postgres.h"
 
+#include "access/compressamapi.h"
+#include "access/detoast.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
 #include "access/tableam.h"
@@ -2036,6 +2038,113 @@ ExecPrepareTupleRouting(ModifyTableState *mtstate,
 	return slot;
 }
 
+/*
+ * Compare the compression method of each compressed value with the
+ * compression method of the target attribute.  If the compression method
+ * of the compressed value is not supported in the target attribute then
+ * decompress the value.  If any of the value need to decompress then we
+ * need to store that into the new slot.
+ *
+ * The slot will hold the input slot but if any of the value need to be
+ * decompressed then the new slot will be stored into this and the old
+ * slot will be dropped.
+ */
+TupleTableSlot *
+CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
+									  TupleTableSlot **outslot,
+									  TupleDesc targetTupDesc)
+{
+	int			i;
+	int			attnum;
+	int			natts = slot->tts_tupleDescriptor->natts;
+	bool		decompressed_any = false;
+	bool		slot_tup_deformed = false;
+	Oid			cmoid;
+	TupleDesc	tupleDesc = slot->tts_tupleDescriptor;
+
+	if (natts == 0)
+		return slot;
+
+	/*
+	 * Loop over all the attributes in the tuple and check if any attribute is
+	 * compressed and its compression method is not same as the target
+	 * atrribute's compression method then decompress it.
+	 */
+	for (i = 0; i < natts; i++)
+	{
+		attnum = tupleDesc->attrs[i].attnum;
+
+		if (TupleDescAttr(tupleDesc, i)->attlen == -1)
+		{
+			struct varlena *new_value;
+
+			/* fetch the values of all the attribute, if not already done */
+			if (!slot_tup_deformed)
+			{
+				slot_getallattrs(slot);
+				slot_tup_deformed = true;
+			}
+
+			/* nothing to be done, if the value is null */
+			if (slot->tts_isnull[attnum - 1])
+				continue;
+
+			new_value = (struct varlena *)
+				DatumGetPointer(slot->tts_values[attnum - 1]);
+
+			/*
+			 * Get the compression method Oid stored in the toast header and
+			 * compare it with the compression method of the target.
+			 */
+			cmoid = toast_get_compression_oid(new_value);
+			if (OidIsValid(cmoid) &&
+				targetTupDesc->attrs[i].attcompression != cmoid)
+			{
+				new_value = detoast_attr(new_value);
+				slot->tts_values[attnum - 1] = PointerGetDatum(new_value);
+				decompressed_any = true;
+			}
+		}
+	}
+
+	/*
+	 * If we have decompressed any of the fields then we need to copy the
+	 * values/null array from oldslot to the new slot and materialize the new
+	 * slot.
+	 */
+	if (decompressed_any)
+	{
+		TupleTableSlot *newslot = *outslot;
+
+		/*
+		 * If the called has passed an invalid slot then create a new slot.
+		 * Otherwise, just clear the existing tuple from the slot.  This slot
+		 * should be stored by the caller so that it can be reused for
+		 * decompressing the subsequent tuples.
+		 */
+		if (newslot == NULL)
+			newslot = MakeSingleTupleTableSlot(tupleDesc, slot->tts_ops);
+		else
+			ExecClearTuple(newslot);
+
+		/*
+		 * Copy the value/null array to the new slot and materialize it,
+		 * before clearing the tuple from the old slot.
+		 */
+		memcpy(newslot->tts_values, slot->tts_values, natts * sizeof(Datum));
+		memcpy(newslot->tts_isnull, slot->tts_isnull, natts * sizeof(bool));
+		ExecStoreVirtualTuple(newslot);
+		ExecMaterializeSlot(newslot);
+		ExecClearTuple(slot);
+
+		*outslot = newslot;
+
+		return newslot;
+	}
+
+	return slot;
+}
+
 /* ----------------------------------------------------------------
  *	   ExecModifyTable
  *
@@ -2244,6 +2353,15 @@ ExecModifyTable(PlanState *pstate)
 				slot = ExecFilterJunk(junkfilter, slot);
 		}
 
+		/*
+		 * Compare the compression method of the compressed attribute in the
+		 * source tuple with target attribute and if those are different then
+		 * decompress those attributes.
+		 */
+		slot = CompareCompressionMethodAndDecompress(slot,
+									&node->mt_decompress_tuple_slot,
+									resultRelInfo->ri_RelationDesc->rd_att);
+
 		switch (operation)
 		{
 			case CMD_INSERT:
@@ -2876,6 +2994,10 @@ ExecEndModifyTable(ModifyTableState *node)
 			ExecDropSingleTupleTableSlot(node->mt_root_tuple_slot);
 	}
 
+	/* release the slot used for decompressing the tuple */
+	if (node->mt_decompress_tuple_slot)
+		ExecDropSingleTupleTableSlot(node->mt_decompress_tuple_slot);
+
 	/*
 	 * Free the exprcontext
 	 */
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 65bbc18ecb..1338e04409 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2966,6 +2966,7 @@ _copyColumnDef(const ColumnDef *from)
 
 	COPY_STRING_FIELD(colname);
 	COPY_NODE_FIELD(typeName);
+	COPY_STRING_FIELD(compression);
 	COPY_SCALAR_FIELD(inhcount);
 	COPY_SCALAR_FIELD(is_local);
 	COPY_SCALAR_FIELD(is_not_null);
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index c2d73626fc..f3592003da 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -2599,6 +2599,7 @@ _equalColumnDef(const ColumnDef *a, const ColumnDef *b)
 {
 	COMPARE_STRING_FIELD(colname);
 	COMPARE_NODE_FIELD(typeName);
+	COMPARE_STRING_FIELD(compression);
 	COMPARE_SCALAR_FIELD(inhcount);
 	COMPARE_SCALAR_FIELD(is_local);
 	COMPARE_SCALAR_FIELD(is_not_null);
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 49357ac5c2..38226530c6 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -3897,6 +3897,8 @@ raw_expression_tree_walker(Node *node,
 
 				if (walker(coldef->typeName, context))
 					return true;
+				if (walker(coldef->compression, context))
+					return true;
 				if (walker(coldef->raw_default, context))
 					return true;
 				if (walker(coldef->collClause, context))
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index f5dcedf6e8..0605ef3f84 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2863,6 +2863,7 @@ _outColumnDef(StringInfo str, const ColumnDef *node)
 
 	WRITE_STRING_FIELD(colname);
 	WRITE_NODE_FIELD(typeName);
+	WRITE_STRING_FIELD(compression);
 	WRITE_INT_FIELD(inhcount);
 	WRITE_BOOL_FIELD(is_local);
 	WRITE_BOOL_FIELD(is_not_null);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index dd72a9fc3c..52d92df25d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -596,6 +596,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <list>		hash_partbound
 %type <defelt>		hash_partbound_elem
 
+%type <str>	optColumnCompression
+
 /*
  * Non-keyword token types.  These are hard-wired into the "flex" lexer.
  * They must be listed first so that their numeric codes do not depend on
@@ -631,9 +633,9 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	CACHE CALL CALLED CASCADE CASCADED CASE CAST CATALOG_P CHAIN CHAR_P
 	CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
 	CLUSTER COALESCE COLLATE COLLATION COLUMN COLUMNS COMMENT COMMENTS COMMIT
-	COMMITTED CONCURRENTLY CONFIGURATION CONFLICT CONNECTION CONSTRAINT
-	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
-	CROSS CSV CUBE CURRENT_P
+	COMMITTED COMPRESSION CONCURRENTLY CONFIGURATION CONFLICT
+	CONNECTION CONSTRAINT CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY
+	COST CREATE CROSS CSV CUBE CURRENT_P
 	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
@@ -3421,11 +3423,12 @@ TypedTableElement:
 			| TableConstraint					{ $$ = $1; }
 		;
 
-columnDef:	ColId Typename create_generic_options ColQualList
+columnDef:	ColId Typename optColumnCompression create_generic_options ColQualList
 				{
 					ColumnDef *n = makeNode(ColumnDef);
 					n->colname = $1;
 					n->typeName = $2;
+					n->compression = $3;
 					n->inhcount = 0;
 					n->is_local = true;
 					n->is_not_null = false;
@@ -3434,8 +3437,8 @@ columnDef:	ColId Typename create_generic_options ColQualList
 					n->raw_default = NULL;
 					n->cooked_default = NULL;
 					n->collOid = InvalidOid;
-					n->fdwoptions = $3;
-					SplitColQualList($4, &n->constraints, &n->collClause,
+					n->fdwoptions = $4;
+					SplitColQualList($5, &n->constraints, &n->collClause,
 									 yyscanner);
 					n->location = @1;
 					$$ = (Node *)n;
@@ -3480,6 +3483,14 @@ columnOptions:	ColId ColQualList
 				}
 		;
 
+optColumnCompression:
+					COMPRESSION name
+					{
+						$$ = $2;
+					}
+					| /*EMPTY*/	{ $$ = NULL; }
+				;
+
 ColQualList:
 			ColQualList ColConstraint				{ $$ = lappend($1, $2); }
 			| /*EMPTY*/								{ $$ = NIL; }
@@ -3710,6 +3721,7 @@ TableLikeOption:
 				| INDEXES			{ $$ = CREATE_TABLE_LIKE_INDEXES; }
 				| STATISTICS		{ $$ = CREATE_TABLE_LIKE_STATISTICS; }
 				| STORAGE			{ $$ = CREATE_TABLE_LIKE_STORAGE; }
+				| COMPRESSION		{ $$ = CREATE_TABLE_LIKE_COMPRESSION; }
 				| ALL				{ $$ = CREATE_TABLE_LIKE_ALL; }
 		;
 
@@ -15285,6 +15297,7 @@ unreserved_keyword:
 			| COMMENTS
 			| COMMIT
 			| COMMITTED
+			| COMPRESSION
 			| CONFIGURATION
 			| CONFLICT
 			| CONNECTION
@@ -15805,6 +15818,7 @@ bare_label_keyword:
 			| COMMENTS
 			| COMMIT
 			| COMMITTED
+			| COMPRESSION
 			| CONCURRENTLY
 			| CONFIGURATION
 			| CONFLICT
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index b31f3afa03..cf4413da64 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -27,6 +27,7 @@
 #include "postgres.h"
 
 #include "access/amapi.h"
+#include "access/compressamapi.h"
 #include "access/htup_details.h"
 #include "access/relation.h"
 #include "access/reloptions.h"
@@ -1082,6 +1083,13 @@ transformTableLikeClause(CreateStmtContext *cxt, TableLikeClause *table_like_cla
 		else
 			def->storage = 0;
 
+		/* Likewise, copy compression if requested */
+		if ((table_like_clause->options & CREATE_TABLE_LIKE_COMPRESSION) != 0
+			&& OidIsValid(attribute->attcompression))
+			def->compression = get_am_name(attribute->attcompression);
+		else
+			def->compression = NULL;
+
 		/* Likewise, copy comment if requested */
 		if ((table_like_clause->options & CREATE_TABLE_LIKE_COMMENTS) &&
 			(comment = GetComment(attribute->attrelid,
diff --git a/src/backend/utils/adt/pseudotypes.c b/src/backend/utils/adt/pseudotypes.c
index c2f910d606..fe133c76c2 100644
--- a/src/backend/utils/adt/pseudotypes.c
+++ b/src/backend/utils/adt/pseudotypes.c
@@ -383,6 +383,7 @@ PSEUDOTYPE_DUMMY_IO_FUNCS(language_handler);
 PSEUDOTYPE_DUMMY_IO_FUNCS(fdw_handler);
 PSEUDOTYPE_DUMMY_IO_FUNCS(table_am_handler);
 PSEUDOTYPE_DUMMY_IO_FUNCS(index_am_handler);
+PSEUDOTYPE_DUMMY_IO_FUNCS(compression_am_handler);
 PSEUDOTYPE_DUMMY_IO_FUNCS(tsm_handler);
 PSEUDOTYPE_DUMMY_IO_FUNCS(internal);
 PSEUDOTYPE_DUMMY_IO_FUNCS(anyelement);
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 479ed9ae54..a35abe5f1a 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -17,9 +17,11 @@
 #include <ctype.h>
 #include <limits.h>
 
+#include "access/compressamapi.h"
 #include "access/detoast.h"
 #include "catalog/pg_collation.h"
 #include "catalog/pg_type.h"
+#include "commands/defrem.h"
 #include "common/hashfn.h"
 #include "common/hex.h"
 #include "common/int.h"
@@ -5299,6 +5301,46 @@ pg_column_size(PG_FUNCTION_ARGS)
 	PG_RETURN_INT32(result);
 }
 
+/*
+ * Return the compression method stored in the compressed attribute.  Return
+ * NULL for non varlena type or the uncompressed data.
+ */
+Datum
+pg_column_compression(PG_FUNCTION_ARGS)
+{
+	Datum		value = PG_GETARG_DATUM(0);
+	int			typlen;
+	Oid			cmoid;
+
+	/* On first call, get the input type's typlen, and save at *fn_extra */
+	if (fcinfo->flinfo->fn_extra == NULL)
+	{
+		/* Lookup the datatype of the supplied argument */
+		Oid			argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
+
+		typlen = get_typlen(argtypeid);
+		if (typlen == 0)		/* should not happen */
+			elog(ERROR, "cache lookup failed for type %u", argtypeid);
+
+		fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+													  sizeof(int));
+		*((int *) fcinfo->flinfo->fn_extra) = typlen;
+	}
+	else
+		typlen = *((int *) fcinfo->flinfo->fn_extra);
+
+	if (typlen != -1)
+		PG_RETURN_NULL();
+
+	cmoid =
+		toast_get_compression_oid((struct varlena *) DatumGetPointer(value));
+
+	if (!OidIsValid(cmoid))
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_TEXT_P(cstring_to_text(get_am_name(cmoid)));
+}
+
 /*
  * string_agg - Concatenates values and returns string.
  *
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index eea9f30a79..7332f93a25 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -160,6 +160,7 @@ typedef struct _dumpOptions
 	int			no_subscriptions;
 	int			no_synchronized_snapshots;
 	int			no_unlogged_table_data;
+	int			no_compression_methods;
 	int			serializable_deferrable;
 	int			disable_triggers;
 	int			outputNoTablespaces;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index eb988d7eb4..46044cb92a 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -387,6 +387,7 @@ main(int argc, char **argv)
 		{"no-synchronized-snapshots", no_argument, &dopt.no_synchronized_snapshots, 1},
 		{"no-unlogged-table-data", no_argument, &dopt.no_unlogged_table_data, 1},
 		{"no-subscriptions", no_argument, &dopt.no_subscriptions, 1},
+		{"no-compression-methods", no_argument, &dopt.no_compression_methods, 1},
 		{"no-sync", no_argument, NULL, 7},
 		{"on-conflict-do-nothing", no_argument, &dopt.do_nothing, 1},
 		{"rows-per-insert", required_argument, NULL, 10},
@@ -1047,6 +1048,7 @@ help(const char *progname)
 	printf(_("  --no-publications            do not dump publications\n"));
 	printf(_("  --no-security-labels         do not dump security label assignments\n"));
 	printf(_("  --no-subscriptions           do not dump subscriptions\n"));
+	printf(_("  --no-compression-methods     do not dump compression methods\n"));
 	printf(_("  --no-synchronized-snapshots  do not use synchronized snapshots in parallel jobs\n"));
 	printf(_("  --no-tablespaces             do not dump tablespace assignments\n"));
 	printf(_("  --no-unlogged-table-data     do not dump unlogged table data\n"));
@@ -8617,6 +8619,7 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 {
 	DumpOptions *dopt = fout->dopt;
 	PQExpBuffer q = createPQExpBuffer();
+	bool		createWithCompression;
 
 	for (int i = 0; i < numTables; i++)
 	{
@@ -8702,6 +8705,15 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 			appendPQExpBufferStr(q,
 								 "'' AS attidentity,\n");
 
+		createWithCompression = (fout->remoteVersion >= 140000);
+
+		if (createWithCompression)
+			appendPQExpBuffer(q,
+							  "am.amname AS attcmname,\n");
+		else
+			appendPQExpBuffer(q,
+							  "NULL AS attcmname,\n");
+
 		if (fout->remoteVersion >= 110000)
 			appendPQExpBufferStr(q,
 								 "CASE WHEN a.atthasmissing AND NOT a.attisdropped "
@@ -8720,7 +8732,12 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 		/* need left join here to not fail on dropped columns ... */
 		appendPQExpBuffer(q,
 						  "FROM pg_catalog.pg_attribute a LEFT JOIN pg_catalog.pg_type t "
-						  "ON a.atttypid = t.oid\n"
+						  "ON a.atttypid = t.oid\n");
+
+		if (createWithCompression)
+			appendPQExpBuffer(q, "LEFT JOIN pg_catalog.pg_am am "
+							  "ON a.attcompression = am.oid\n");
+		appendPQExpBuffer(q,
 						  "WHERE a.attrelid = '%u'::pg_catalog.oid "
 						  "AND a.attnum > 0::pg_catalog.int2\n"
 						  "ORDER BY a.attnum",
@@ -8747,6 +8764,7 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 		tbinfo->attcollation = (Oid *) pg_malloc(ntups * sizeof(Oid));
 		tbinfo->attfdwoptions = (char **) pg_malloc(ntups * sizeof(char *));
 		tbinfo->attmissingval = (char **) pg_malloc(ntups * sizeof(char *));
+		tbinfo->attcmnames = (char **) pg_malloc(ntups * sizeof(char *));
 		tbinfo->notnull = (bool *) pg_malloc(ntups * sizeof(bool));
 		tbinfo->inhNotNull = (bool *) pg_malloc(ntups * sizeof(bool));
 		tbinfo->attrdefs = (AttrDefInfo **) pg_malloc(ntups * sizeof(AttrDefInfo *));
@@ -8775,6 +8793,7 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 			tbinfo->attcollation[j] = atooid(PQgetvalue(res, j, PQfnumber(res, "attcollation")));
 			tbinfo->attfdwoptions[j] = pg_strdup(PQgetvalue(res, j, PQfnumber(res, "attfdwoptions")));
 			tbinfo->attmissingval[j] = pg_strdup(PQgetvalue(res, j, PQfnumber(res, "attmissingval")));
+			tbinfo->attcmnames[j] = pg_strdup(PQgetvalue(res, j, PQfnumber(res, "attcmname")));
 			tbinfo->attrdefs[j] = NULL; /* fix below */
 			if (PQgetvalue(res, j, PQfnumber(res, "atthasdef"))[0] == 't')
 				hasdefaults = true;
@@ -15832,6 +15851,7 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo)
 				{
 					bool		print_default;
 					bool		print_notnull;
+					bool		has_non_default_compression;
 
 					/*
 					 * Default value --- suppress if to be printed separately.
@@ -15856,6 +15876,9 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo)
 						!dopt->binary_upgrade)
 						continue;
 
+					has_non_default_compression = (tbinfo->attcmnames[j] &&
+												   (strcmp(tbinfo->attcmnames[j], "pglz") != 0));
+
 					/* Format properly if not first attr */
 					if (actual_atts == 0)
 						appendPQExpBufferStr(q, " (");
@@ -15891,6 +15914,17 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo)
 										  tbinfo->atttypnames[j]);
 					}
 
+					/*
+					 * Attribute compression
+					 */
+					if (!dopt->no_compression_methods &&
+						tbinfo->attcmnames[j] && strlen(tbinfo->attcmnames[j]) &&
+						(has_non_default_compression || dopt->binary_upgrade))
+					{
+						appendPQExpBuffer(q, " COMPRESSION %s",
+										  tbinfo->attcmnames[j]);
+					}
+
 					if (print_default)
 					{
 						if (tbinfo->attgenerated[j] == ATTRIBUTE_GENERATED_STORED)
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 0a2213fb06..1789e18f46 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -326,6 +326,7 @@ typedef struct _tableInfo
 	char	   *partbound;		/* partition bound definition */
 	bool		needs_override; /* has GENERATED ALWAYS AS IDENTITY */
 	char	   *amname;			/* relation access method */
+	char	  **attcmnames;		/* per-attribute current compression method */
 
 	/*
 	 * Stuff computed only for dumpable tables.
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 737e46464a..97791f8dbe 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -2284,9 +2284,9 @@ my %tests = (
 		regexp => qr/^
 			\QCREATE TABLE dump_test.test_table (\E\n
 			\s+\Qcol1 integer NOT NULL,\E\n
-			\s+\Qcol2 text,\E\n
-			\s+\Qcol3 text,\E\n
-			\s+\Qcol4 text,\E\n
+			\s+\Qcol2 text\E\D*,\n
+			\s+\Qcol3 text\E\D*,\n
+			\s+\Qcol4 text\E\D*,\n
 			\s+\QCONSTRAINT test_table_col1_check CHECK ((col1 <= 1000))\E\n
 			\Q)\E\n
 			\QWITH (autovacuum_enabled='false', fillfactor='80');\E\n/xm,
@@ -2326,7 +2326,7 @@ my %tests = (
 		regexp => qr/^
 			\QCREATE TABLE dump_test.test_second_table (\E
 			\n\s+\Qcol1 integer,\E
-			\n\s+\Qcol2 text\E
+			\n\s+\Qcol2 text\E\D*
 			\n\);
 			/xm,
 		like =>
@@ -2441,7 +2441,7 @@ my %tests = (
 			\n\s+\Qcol1 integer,\E
 			\n\s+\Qcol2 boolean,\E
 			\n\s+\Qcol3 boolean,\E
-			\n\s+\Qcol4 bit(5),\E
+			\n\s+\Qcol4 bit(5)\E\D*,
 			\n\s+\Qcol5 double precision\E
 			\n\);
 			/xm,
@@ -2459,7 +2459,7 @@ my %tests = (
 		regexp => qr/^
 			\QCREATE TABLE dump_test.test_table_identity (\E\n
 			\s+\Qcol1 integer NOT NULL,\E\n
-			\s+\Qcol2 text\E\n
+			\s+\Qcol2 text\E\D*\n
 			\);
 			.*
 			\QALTER TABLE dump_test.test_table_identity ALTER COLUMN col1 ADD GENERATED ALWAYS AS IDENTITY (\E\n
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 20af5a92b4..ba464d463e 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -170,10 +170,12 @@ describeAccessMethods(const char *pattern, bool verbose)
 					  "  CASE amtype"
 					  " WHEN 'i' THEN '%s'"
 					  " WHEN 't' THEN '%s'"
+					  " WHEN 'c' THEN '%s'"
 					  " END AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Index"),
 					  gettext_noop("Table"),
+					  gettext_noop("Compression"),
 					  gettext_noop("Type"));
 
 	if (verbose)
@@ -1459,7 +1461,7 @@ describeOneTableDetails(const char *schemaname,
 	bool		printTableInitialized = false;
 	int			i;
 	char	   *view_def = NULL;
-	char	   *headers[11];
+	char	   *headers[12];
 	PQExpBufferData title;
 	PQExpBufferData tmpbuf;
 	int			cols;
@@ -1475,7 +1477,8 @@ describeOneTableDetails(const char *schemaname,
 				fdwopts_col = -1,
 				attstorage_col = -1,
 				attstattarget_col = -1,
-				attdescr_col = -1;
+				attdescr_col = -1,
+				attcompression_col = -1;
 	int			numrows;
 	struct
 	{
@@ -1892,6 +1895,20 @@ describeOneTableDetails(const char *schemaname,
 		appendPQExpBufferStr(&buf, ",\n  a.attstorage");
 		attstorage_col = cols++;
 
+		/* compresssion info */
+		if (pset.sversion >= 140000 &&
+			(tableinfo.relkind == RELKIND_RELATION ||
+			 tableinfo.relkind == RELKIND_PARTITIONED_TABLE ||
+			 tableinfo.relkind == RELKIND_MATVIEW))
+		{
+			appendPQExpBufferStr(&buf, ",\n  CASE WHEN attcompression = 0 THEN NULL ELSE "
+								 " (SELECT am.amname "
+								 "  FROM pg_catalog.pg_am am "
+								 "  WHERE am.oid = a.attcompression) "
+								 " END AS attcompression");
+			attcompression_col = cols++;
+		}
+
 		/* stats target, if relevant to relkind */
 		if (tableinfo.relkind == RELKIND_RELATION ||
 			tableinfo.relkind == RELKIND_INDEX ||
@@ -2018,6 +2035,8 @@ describeOneTableDetails(const char *schemaname,
 		headers[cols++] = gettext_noop("FDW options");
 	if (attstorage_col >= 0)
 		headers[cols++] = gettext_noop("Storage");
+	if (attcompression_col >= 0)
+		headers[cols++] = gettext_noop("Compression");
 	if (attstattarget_col >= 0)
 		headers[cols++] = gettext_noop("Stats target");
 	if (attdescr_col >= 0)
@@ -2097,6 +2116,11 @@ describeOneTableDetails(const char *schemaname,
 							  false, false);
 		}
 
+		/* Column compression */
+		if (attcompression_col >= 0)
+			printTableAddCell(&cont, PQgetvalue(res, i, attcompression_col),
+							  false, false);
+
 		/* Statistics target, if the relkind supports this feature */
 		if (attstattarget_col >= 0)
 			printTableAddCell(&cont, PQgetvalue(res, i, attstattarget_col),
diff --git a/src/include/access/compressamapi.h b/src/include/access/compressamapi.h
new file mode 100644
index 0000000000..5a8e23d926
--- /dev/null
+++ b/src/include/access/compressamapi.h
@@ -0,0 +1,99 @@
+/*-------------------------------------------------------------------------
+ *
+ * compressamapi.h
+ *	  API for Postgres compression methods.
+ *
+ * Portions Copyright (c) 2021, PostgreSQL Global Development Group
+ *
+ * src/include/access/compressamapi.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef COMPRESSAMAPI_H
+#define COMPRESSAMAPI_H
+
+#include "postgres.h"
+
+#include "catalog/pg_am_d.h"
+#include "nodes/nodes.h"
+
+/*
+ * Built-in compression method-id.  The toast compression header will store
+ * this in the first 2 bits of the raw length.  These built-in compression
+ * method-id are directly mapped to the built-in compression method oid.
+ */
+typedef enum CompressionId
+{
+	PGLZ_COMPRESSION_ID = 0,
+	LZ4_COMPRESSION_ID = 1
+} CompressionId;
+
+/* Use default compression method if it is not specified. */
+#define DefaultCompressionOid	PGLZ_COMPRESSION_AM_OID
+#define IsStorageCompressible(storage) ((storage) != TYPSTORAGE_PLAIN && \
+										(storage) != TYPSTORAGE_EXTERNAL)
+/* compression handler routines */
+typedef struct varlena *(*cmcompress_function) (const struct varlena *value);
+typedef struct varlena *(*cmdecompress_function) (const struct varlena *value);
+typedef struct varlena *(*cmdecompress_slice_function)
+			(const struct varlena *value, int32 slicelength);
+
+/*
+ * API struct for a compression AM.
+ *
+ * 'datum_compress' - varlena compression function.
+ * 'datum_decompress' - varlena decompression function.
+ * 'datum_decompress_slice' - varlena slice decompression functions.
+ */
+typedef struct CompressionAmRoutine
+{
+	NodeTag		type;
+
+	cmcompress_function datum_compress;
+	cmdecompress_function datum_decompress;
+	cmdecompress_slice_function datum_decompress_slice;
+} CompressionAmRoutine;
+
+extern const CompressionAmRoutine pglz_compress_methods;
+extern const CompressionAmRoutine lz4_compress_methods;
+
+/*
+ * CompressionOidToId - Convert compression Oid to built-in compression id.
+ *
+ * For more details refer comment atop CompressionId in compressamapi.h
+ */
+static inline CompressionId
+CompressionOidToId(Oid cmoid)
+{
+	switch (cmoid)
+	{
+		case PGLZ_COMPRESSION_AM_OID:
+			return PGLZ_COMPRESSION_ID;
+		case LZ4_COMPRESSION_AM_OID:
+			return LZ4_COMPRESSION_ID;
+		default:
+			elog(ERROR, "invalid compression method oid %u", cmoid);
+	}
+}
+
+/*
+ * CompressionIdToOid - Convert built-in compression id to Oid
+ *
+ * For more details refer comment atop CompressionId in compressamapi.h
+ */
+static inline Oid
+CompressionIdToOid(CompressionId cmid)
+{
+	switch (cmid)
+	{
+		case PGLZ_COMPRESSION_ID:
+			return PGLZ_COMPRESSION_AM_OID;
+		case LZ4_COMPRESSION_ID:
+			return LZ4_COMPRESSION_AM_OID;
+		default:
+			elog(ERROR, "invalid compression method id %d", cmid);
+	}
+}
+
+#endif							/* COMPRESSAMAPI_H */
diff --git a/src/include/access/detoast.h b/src/include/access/detoast.h
index 0adf53c77b..6cdc37542d 100644
--- a/src/include/access/detoast.h
+++ b/src/include/access/detoast.h
@@ -89,4 +89,12 @@ extern Size toast_raw_datum_size(Datum value);
  */
 extern Size toast_datum_size(Datum value);
 
+/* ----------
+ * toast_get_compression_oid -
+ *
+ *	Return the compression method oid from the compressed value
+ * ----------
+ */
+extern Oid toast_get_compression_oid(struct varlena *attr);
+
 #endif							/* DETOAST_H */
diff --git a/src/include/access/toast_helper.h b/src/include/access/toast_helper.h
index a9a6d644bc..dca0bc37f3 100644
--- a/src/include/access/toast_helper.h
+++ b/src/include/access/toast_helper.h
@@ -32,6 +32,7 @@ typedef struct
 	struct varlena *tai_oldexternal;
 	int32		tai_size;
 	uint8		tai_colflags;
+	Oid			tai_compression;
 } ToastAttrInfo;
 
 /*
diff --git a/src/include/access/toast_internals.h b/src/include/access/toast_internals.h
index cedfb890d8..31ff91a09c 100644
--- a/src/include/access/toast_internals.h
+++ b/src/include/access/toast_internals.h
@@ -12,6 +12,7 @@
 #ifndef TOAST_INTERNALS_H
 #define TOAST_INTERNALS_H
 
+#include "access/compressamapi.h"
 #include "storage/lockdefs.h"
 #include "utils/relcache.h"
 #include "utils/snapshot.h"
@@ -22,22 +23,22 @@
 typedef struct toast_compress_header
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
-	int32		rawsize;
+	uint32		info;			/* 2 bits for compression method and 30 bits
+								 * rawsize */
 } toast_compress_header;
 
 /*
  * Utilities for manipulation of header information for compressed
  * toast entries.
  */
-#define TOAST_COMPRESS_HDRSZ		((int32) sizeof(toast_compress_header))
-#define TOAST_COMPRESS_RAWSIZE(ptr) (((toast_compress_header *) (ptr))->rawsize)
-#define TOAST_COMPRESS_SIZE(ptr)	((int32) VARSIZE_ANY(ptr) - TOAST_COMPRESS_HDRSZ)
-#define TOAST_COMPRESS_RAWDATA(ptr) \
-	(((char *) (ptr)) + TOAST_COMPRESS_HDRSZ)
-#define TOAST_COMPRESS_SET_RAWSIZE(ptr, len) \
-	(((toast_compress_header *) (ptr))->rawsize = (len))
+#define TOAST_COMPRESS_METHOD(ptr)  (((toast_compress_header *) (ptr))->info >> VARLENA_RAWSIZE_BITS)
+#define TOAST_COMPRESS_SET_SIZE_AND_METHOD(ptr, len, cm_method) \
+	do { \
+		Assert((len) > 0 && (len) <= VARLENA_RAWSIZE_MASK); \
+		((toast_compress_header *) (ptr))->info = ((len) | (cm_method) << VARLENA_RAWSIZE_BITS); \
+	} while (0)
 
-extern Datum toast_compress_datum(Datum value);
+extern Datum toast_compress_datum(Datum value, Oid cmoid);
 extern Oid	toast_get_valid_index(Oid toastoid, LOCKMODE lock);
 
 extern void toast_delete_datum(Relation rel, Datum value, bool is_speculative);
diff --git a/src/include/catalog/pg_am.dat b/src/include/catalog/pg_am.dat
index 6082f0e6a8..605684408c 100644
--- a/src/include/catalog/pg_am.dat
+++ b/src/include/catalog/pg_am.dat
@@ -33,5 +33,11 @@
 { oid => '3580', oid_symbol => 'BRIN_AM_OID',
   descr => 'block range index (BRIN) access method',
   amname => 'brin', amhandler => 'brinhandler', amtype => 'i' },
+{ oid => '4572', oid_symbol => 'PGLZ_COMPRESSION_AM_OID',
+  descr => 'pglz compression access method',
+  amname => 'pglz', amhandler => 'pglzhandler', amtype => 'c' },
+{ oid => '4573', oid_symbol => 'LZ4_COMPRESSION_AM_OID',
+  descr => 'lz4 compression access method',
+  amname => 'lz4', amhandler => 'lz4handler', amtype => 'c' },
 
 ]
diff --git a/src/include/catalog/pg_am.h b/src/include/catalog/pg_am.h
index ced86faef8..65079f3821 100644
--- a/src/include/catalog/pg_am.h
+++ b/src/include/catalog/pg_am.h
@@ -59,6 +59,7 @@ DECLARE_UNIQUE_INDEX_PKEY(pg_am_oid_index, 2652, on pg_am using btree(oid oid_op
  */
 #define AMTYPE_INDEX					'i' /* index access method */
 #define AMTYPE_TABLE					't' /* table access method */
+#define AMTYPE_COMPRESSION				'c'	/* compression access method */
 
 #endif							/* EXPOSE_TO_CLIENT_CODE */
 
diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h
index 3db42abf08..797e78b17c 100644
--- a/src/include/catalog/pg_attribute.h
+++ b/src/include/catalog/pg_attribute.h
@@ -160,6 +160,12 @@ CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,
 	/* attribute's collation, if any */
 	Oid			attcollation BKI_LOOKUP_OPT(pg_collation);
 
+	/*
+	 * OID of compression AM.  Must be InvalidOid if and only if typstorage is
+	 * 'plain' or 'external'.
+	 */
+	Oid			attcompression BKI_DEFAULT(0);
+
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	/* NOTE: The following fields are not present in tuple descriptors. */
 
@@ -187,7 +193,7 @@ CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,
  * can access fields beyond attcollation except in a real tuple!
  */
 #define ATTRIBUTE_FIXED_PART_SIZE \
-	(offsetof(FormData_pg_attribute,attcollation) + sizeof(Oid))
+	(offsetof(FormData_pg_attribute,attcompression) + sizeof(Oid))
 
 /* ----------------
  *		Form_pg_attribute corresponds to a pointer to a tuple with
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4e0c9be58c..4a13844ce6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -941,6 +941,15 @@
   prorettype => 'void', proargtypes => 'regclass int8',
   prosrc => 'brin_desummarize_range' },
 
+{ oid => '6015', descr => 'pglz compression access method handler',
+  proname => 'pglzhandler', provolatile => 'v',
+  prorettype => 'compression_am_handler', proargtypes => 'internal',
+  prosrc => 'pglzhandler' },
+{ oid => '6016', descr => 'lz4 compression access method handler',
+  proname => 'lz4handler', provolatile => 'v',
+  prorettype => 'compression_am_handler', proargtypes => 'internal',
+  prosrc => 'lz4handler' },
+
 { oid => '338', descr => 'validate an operator class',
   proname => 'amvalidate', provolatile => 'v', prorettype => 'bool',
   proargtypes => 'oid', prosrc => 'amvalidate' },
@@ -7095,6 +7104,10 @@
   descr => 'bytes required to store the value, perhaps with compression',
   proname => 'pg_column_size', provolatile => 's', prorettype => 'int4',
   proargtypes => 'any', prosrc => 'pg_column_size' },
+{ oid => '2121',
+  descr => 'compression method for the compressed datum',
+  proname => 'pg_column_compression', provolatile => 's', prorettype => 'text',
+  proargtypes => 'any', prosrc => 'pg_column_compression' },
 { oid => '2322',
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
@@ -7265,6 +7278,13 @@
 { oid => '268', descr => 'I/O',
   proname => 'table_am_handler_out', prorettype => 'cstring',
   proargtypes => 'table_am_handler', prosrc => 'table_am_handler_out' },
+{ oid => '560', descr => 'I/O',
+  proname => 'compression_am_handler_in', proisstrict => 'f',
+  prorettype => 'compression_am_handler', proargtypes => 'cstring',
+  prosrc => 'compression_am_handler_in' },
+{ oid => '561', descr => 'I/O',
+  proname => 'compression_am_handler_out', prorettype => 'cstring',
+  proargtypes => 'compression_am_handler', prosrc => 'compression_am_handler_out' },
 { oid => '5086', descr => 'I/O',
   proname => 'anycompatible_in', prorettype => 'anycompatible',
   proargtypes => 'cstring', prosrc => 'anycompatible_in' },
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 8959c2f53b..306aabf6c1 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -626,6 +626,11 @@
   typcategory => 'P', typinput => 'index_am_handler_in',
   typoutput => 'index_am_handler_out', typreceive => '-', typsend => '-',
   typalign => 'i' },
+ { oid => '5559',
+  typname => 'compression_am_handler', typlen => '4', typbyval => 't', typtype => 'p',
+  typcategory => 'P', typinput => 'compression_am_handler_in',
+  typoutput => 'compression_am_handler_out', typreceive => '-', typsend => '-',
+  typalign => 'i' },
 { oid => '3310',
   descr => 'pseudo-type for the result of a tablesample method function',
   typname => 'tsm_handler', typlen => '4', typbyval => 't', typtype => 'p',
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 1a79540c94..e5aea8a240 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -139,6 +139,7 @@ extern Datum transformGenericOptions(Oid catalogId,
 extern ObjectAddress CreateAccessMethod(CreateAmStmt *stmt);
 extern Oid	get_index_am_oid(const char *amname, bool missing_ok);
 extern Oid	get_table_am_oid(const char *amname, bool missing_ok);
+extern Oid	get_compression_am_oid(const char *amname, bool missing_ok);
 extern Oid	get_am_oid(const char *amname, bool missing_ok);
 extern char *get_am_name(Oid amOid);
 
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 071e363d54..6495162a33 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -621,5 +621,7 @@ extern void CheckCmdReplicaIdentity(Relation rel, CmdType cmd);
 
 extern void CheckSubscriptionRelkind(char relkind, const char *nspname,
 									 const char *relname);
-
+extern TupleTableSlot *CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
+												  TupleTableSlot **outslot,
+												  TupleDesc targetTupDesc);
 #endif							/* EXECUTOR_H  */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index b6a88ff76b..18e8ecfd90 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1182,6 +1182,12 @@ typedef struct ModifyTableState
 	 */
 	TupleTableSlot *mt_root_tuple_slot;
 
+	/*
+	 * Slot for storing the modified tuple, incase the target attribute's
+	 * compression method doesn't match with the source table.
+	 */
+	TupleTableSlot *mt_decompress_tuple_slot;
+
 	/* Tuple-routing support info */
 	struct PartitionTupleRouting *mt_partition_tuple_routing;
 
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 40ae489c23..20d6f96f62 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -512,6 +512,7 @@ typedef enum NodeTag
 	T_IndexAmRoutine,			/* in access/amapi.h */
 	T_TableAmRoutine,			/* in access/tableam.h */
 	T_TsmRoutine,				/* in access/tsmapi.h */
+	T_CompressionAmRoutine,		/* in access/compressamapi.h */
 	T_ForeignKeyCacheInfo,		/* in utils/rel.h */
 	T_CallContext,				/* in nodes/parsenodes.h */
 	T_SupportRequestSimplify,	/* in nodes/supportnodes.h */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 236832a2ca..19d2ba26bf 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -646,6 +646,7 @@ typedef struct ColumnDef
 	NodeTag		type;
 	char	   *colname;		/* name of column */
 	TypeName   *typeName;		/* type of column */
+	char	   *compression;	/* compression method for column */
 	int			inhcount;		/* number of times column is inherited */
 	bool		is_local;		/* column has local (non-inherited) def'n */
 	bool		is_not_null;	/* NOT NULL constraint specified? */
@@ -685,6 +686,7 @@ typedef enum TableLikeOption
 	CREATE_TABLE_LIKE_INDEXES = 1 << 5,
 	CREATE_TABLE_LIKE_STATISTICS = 1 << 6,
 	CREATE_TABLE_LIKE_STORAGE = 1 << 7,
+	CREATE_TABLE_LIKE_COMPRESSION = 1 << 8,
 	CREATE_TABLE_LIKE_ALL = PG_INT32_MAX
 } TableLikeOption;
 
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 28083aaac9..ca1f950cbe 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -88,6 +88,7 @@ PG_KEYWORD("comment", COMMENT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("comments", COMMENTS, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("commit", COMMIT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("committed", COMMITTED, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("compression", COMPRESSION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("concurrently", CONCURRENTLY, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("configuration", CONFIGURATION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("conflict", CONFLICT, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 55cab4d2bf..53d378b67d 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -346,6 +346,9 @@
 /* Define to 1 if you have the `z' library (-lz). */
 #undef HAVE_LIBZ
 
+/* Define to 1 if you have the `lz4' library (-llz4). */
+#undef HAVE_LIBLZ4
+
 /* Define to 1 if you have the `link' function. */
 #undef HAVE_LINK
 
diff --git a/src/include/postgres.h b/src/include/postgres.h
index 2ed572004d..667927fd7c 100644
--- a/src/include/postgres.h
+++ b/src/include/postgres.h
@@ -145,7 +145,8 @@ typedef union
 	struct						/* Compressed-in-line format */
 	{
 		uint32		va_header;
-		uint32		va_rawsize; /* Original data size (excludes header) */
+		uint32		va_info;	/* Original data size (excludes header) and
+								 * flags */
 		char		va_data[FLEXIBLE_ARRAY_MEMBER]; /* Compressed data */
 	}			va_compressed;
 } varattrib_4b;
@@ -274,14 +275,21 @@ typedef struct
 	(VARSIZE(PTR) - VARHDRSZ + VARHDRSZ_SHORT)
 
 #define VARHDRSZ_EXTERNAL		offsetof(varattrib_1b_e, va_data)
+#define VARHDRSZ_COMPRESS		offsetof(varattrib_4b, va_compressed.va_data)
 
 #define VARDATA_4B(PTR)		(((varattrib_4b *) (PTR))->va_4byte.va_data)
 #define VARDATA_4B_C(PTR)	(((varattrib_4b *) (PTR))->va_compressed.va_data)
 #define VARDATA_1B(PTR)		(((varattrib_1b *) (PTR))->va_data)
 #define VARDATA_1B_E(PTR)	(((varattrib_1b_e *) (PTR))->va_data)
 
+#define VARLENA_RAWSIZE_BITS	30
+#define VARLENA_RAWSIZE_MASK	((1U << VARLENA_RAWSIZE_BITS) - 1)
+
+/* va_info in va_compress contains raw size of datum and optional flags */
 #define VARRAWSIZE_4B_C(PTR) \
-	(((varattrib_4b *) (PTR))->va_compressed.va_rawsize)
+	(((varattrib_4b *) (PTR))->va_compressed.va_info & VARLENA_RAWSIZE_MASK)
+#define VARFLAGS_4B_C(PTR) \
+	(((varattrib_4b *) (PTR))->va_compressed.va_info >> VARLENA_RAWSIZE_BITS)
 
 /* Externally visible macros */
 
diff --git a/src/test/regress/expected/compression.out b/src/test/regress/expected/compression.out
new file mode 100644
index 0000000000..167878e78b
--- /dev/null
+++ b/src/test/regress/expected/compression.out
@@ -0,0 +1,201 @@
+\set HIDE_COMPRESSAM off
+-- test creating table with compression method
+CREATE TABLE cmdata(f1 text COMPRESSION pglz);
+CREATE INDEX idx ON cmdata(f1);
+INSERT INTO cmdata VALUES(repeat('1234567890',1000));
+\d+ cmdata
+                                 Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
+--------+------+-----------+----------+---------+----------+--------------+-------------
+ f1     | text |           |          |         | extended |              | 
+Indexes:
+    "idx" btree (f1)
+
+CREATE TABLE cmdata1(f1 TEXT COMPRESSION lz4);
+INSERT INTO cmdata1 VALUES(repeat('1234567890',1004));
+\d+ cmdata1
+                                 Table "public.cmdata1"
+ Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
+--------+------+-----------+----------+---------+----------+--------------+-------------
+ f1     | text |           |          |         | extended |              | 
+
+-- try setting compression for incompressible data type
+CREATE TABLE cmdata2 (f1 int COMPRESSION pglz);
+ERROR:  column data type integer does not support compression
+-- verify stored compression method
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+SELECT pg_column_compression(f1) FROM cmdata1;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+-- decompress data slice
+SELECT SUBSTR(f1, 200, 5) FROM cmdata;
+ substr 
+--------
+ 01234
+(1 row)
+
+SELECT SUBSTR(f1, 2000, 50) FROM cmdata1;
+                       substr                       
+----------------------------------------------------
+ 01234567890123456789012345678901234567890123456789
+(1 row)
+
+-- copy with table creation
+SELECT * INTO cmmove1 FROM cmdata;
+SELECT pg_column_compression(f1) FROM cmmove1;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- update using datum from different table
+CREATE TABLE cmmove2(f1 text COMPRESSION pglz);
+INSERT INTO cmmove2 VALUES (repeat('1234567890',1004));
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+UPDATE cmmove2 SET f1 = cmdata.f1 FROM cmdata;
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+UPDATE cmmove2 SET f1 = cmdata1.f1 FROM cmdata1;
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- copy to existing table
+CREATE TABLE cmmove3(f1 text COMPRESSION pglz);
+INSERT INTO cmmove3 SELECT * FROM cmdata;
+INSERT INTO cmmove3 SELECT * FROM cmdata1;
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- test external compressed data
+CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS
+'select array_agg(md5(g::text))::text from generate_series(1, 256) g';
+CREATE TABLE cmdata2 (f1 text COMPRESSION pglz);
+INSERT INTO cmdata2 select large_val() || repeat('a', 4000);
+SELECT pg_column_compression(f1) FROM cmdata2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+INSERT INTO cmdata1 SELECT * FROM cmdata2;
+SELECT pg_column_compression(f1) FROM cmdata1;
+ pg_column_compression 
+-----------------------
+ lz4
+ lz4
+(2 rows)
+
+DROP TABLE cmdata2;
+-- test LIKE INCLUDING COMPRESSION
+CREATE TABLE cmdata2 (LIKE cmdata1 INCLUDING COMPRESSION);
+\d+ cmdata2
+                                 Table "public.cmdata2"
+ Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
+--------+------+-----------+----------+---------+----------+--------------+-------------
+ f1     | text |           |          |         | extended |              | 
+
+-- test compression with materialized view
+CREATE MATERIALIZED VIEW mv(x) AS SELECT * FROM cmdata1;
+\d+ mv
+                             Materialized view "public.mv"
+ Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
+--------+------+-----------+----------+---------+----------+--------------+-------------
+ x      | text |           |          |         | extended |              | 
+View definition:
+ SELECT cmdata1.f1 AS x
+   FROM cmdata1;
+
+SELECT pg_column_compression(f1) FROM cmdata1;
+ pg_column_compression 
+-----------------------
+ lz4
+ lz4
+(2 rows)
+
+SELECT pg_column_compression(x) FROM mv;
+ pg_column_compression 
+-----------------------
+ pglz
+ pglz
+(2 rows)
+
+-- test compression with partition
+CREATE TABLE cmpart(f1 text COMPRESSION lz4) PARTITION BY HASH(f1);
+CREATE TABLE cmpart1 PARTITION OF cmpart FOR VALUES WITH (MODULUS 2, REMAINDER 0);
+CREATE TABLE cmpart2(f1 text COMPRESSION pglz);
+ALTER TABLE cmpart ATTACH PARTITION cmpart2 FOR VALUES WITH (MODULUS 2, REMAINDER 1);
+INSERT INTO cmpart VALUES (repeat('123456789',1004));
+INSERT INTO cmpart VALUES (repeat('123456789',4004));
+SELECT pg_column_compression(f1) FROM cmpart;
+ pg_column_compression 
+-----------------------
+ lz4
+ pglz
+(2 rows)
+
+-- test compression with inheritence, error
+CREATE TABLE cminh() INHERITS(cmdata, cmdata1);
+NOTICE:  merging multiple inherited definitions of column "f1"
+ERROR:  column "f1" has a compression method conflict
+DETAIL:  pglz versus lz4
+CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
+NOTICE:  merging column "f1" with inherited definition
+ERROR:  column "f1" has a compression method conflict
+DETAIL:  pglz versus lz4
+-- check data is ok
+SELECT length(f1) FROM cmdata;
+ length 
+--------
+  10000
+(1 row)
+
+SELECT length(f1) FROM cmdata1;
+ length 
+--------
+  10040
+  12449
+(2 rows)
+
+SELECT length(f1) FROM cmmove1;
+ length 
+--------
+  10000
+(1 row)
+
+SELECT length(f1) FROM cmmove2;
+ length 
+--------
+  10040
+(1 row)
+
+SELECT length(f1) FROM cmmove3;
+ length 
+--------
+  10000
+  10040
+(2 rows)
+
+\set HIDE_COMPRESSAM on
diff --git a/src/test/regress/expected/compression_1.out b/src/test/regress/expected/compression_1.out
new file mode 100644
index 0000000000..329e7881b0
--- /dev/null
+++ b/src/test/regress/expected/compression_1.out
@@ -0,0 +1,189 @@
+\set HIDE_COMPRESSAM off
+-- test creating table with compression method
+CREATE TABLE cmdata(f1 text COMPRESSION pglz);
+CREATE INDEX idx ON cmdata(f1);
+INSERT INTO cmdata VALUES(repeat('1234567890',1000));
+\d+ cmdata
+                                 Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
+--------+------+-----------+----------+---------+----------+--------------+-------------
+ f1     | text |           |          |         | extended |              | 
+Indexes:
+    "idx" btree (f1)
+
+CREATE TABLE cmdata1(f1 TEXT COMPRESSION lz4);
+ERROR:  not built with lz4 support
+INSERT INTO cmdata1 VALUES(repeat('1234567890',1004));
+ERROR:  relation "cmdata1" does not exist
+LINE 1: INSERT INTO cmdata1 VALUES(repeat('1234567890',1004));
+                    ^
+\d+ cmdata1
+-- try setting compression for incompressible data type
+CREATE TABLE cmdata2 (f1 int COMPRESSION pglz);
+ERROR:  column data type integer does not support compression
+-- verify stored compression method
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+SELECT pg_column_compression(f1) FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmdata1;
+                                              ^
+-- decompress data slice
+SELECT SUBSTR(f1, 200, 5) FROM cmdata;
+ substr 
+--------
+ 01234
+(1 row)
+
+SELECT SUBSTR(f1, 2000, 50) FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: SELECT SUBSTR(f1, 2000, 50) FROM cmdata1;
+                                         ^
+-- copy with table creation
+SELECT * INTO cmmove1 FROM cmdata;
+SELECT pg_column_compression(f1) FROM cmmove1;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- update using datum from different table
+CREATE TABLE cmmove2(f1 text COMPRESSION pglz);
+INSERT INTO cmmove2 VALUES (repeat('1234567890',1004));
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+UPDATE cmmove2 SET f1 = cmdata.f1 FROM cmdata;
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+UPDATE cmmove2 SET f1 = cmdata1.f1 FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: UPDATE cmmove2 SET f1 = cmdata1.f1 FROM cmdata1;
+                                                ^
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- copy to existing table
+CREATE TABLE cmmove3(f1 text COMPRESSION pglz);
+INSERT INTO cmmove3 SELECT * FROM cmdata;
+INSERT INTO cmmove3 SELECT * FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: INSERT INTO cmmove3 SELECT * FROM cmdata1;
+                                          ^
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- test external compressed data
+CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS
+'select array_agg(md5(g::text))::text from generate_series(1, 256) g';
+CREATE TABLE cmdata2 (f1 text COMPRESSION pglz);
+INSERT INTO cmdata2 select large_val() || repeat('a', 4000);
+SELECT pg_column_compression(f1) FROM cmdata2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+INSERT INTO cmdata1 SELECT * FROM cmdata2;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: INSERT INTO cmdata1 SELECT * FROM cmdata2;
+                    ^
+SELECT pg_column_compression(f1) FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmdata1;
+                                              ^
+DROP TABLE cmdata2;
+-- test LIKE INCLUDING COMPRESSION
+CREATE TABLE cmdata2 (LIKE cmdata1 INCLUDING COMPRESSION);
+ERROR:  relation "cmdata1" does not exist
+LINE 1: CREATE TABLE cmdata2 (LIKE cmdata1 INCLUDING COMPRESSION);
+                                   ^
+\d+ cmdata2
+-- test compression with materialized view
+CREATE MATERIALIZED VIEW mv(x) AS SELECT * FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: CREATE MATERIALIZED VIEW mv(x) AS SELECT * FROM cmdata1;
+                                                        ^
+\d+ mv
+SELECT pg_column_compression(f1) FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmdata1;
+                                              ^
+SELECT pg_column_compression(x) FROM mv;
+ERROR:  relation "mv" does not exist
+LINE 1: SELECT pg_column_compression(x) FROM mv;
+                                             ^
+-- test compression with partition
+CREATE TABLE cmpart(f1 text COMPRESSION lz4) PARTITION BY HASH(f1);
+ERROR:  not built with lz4 support
+CREATE TABLE cmpart1 PARTITION OF cmpart FOR VALUES WITH (MODULUS 2, REMAINDER 0);
+ERROR:  relation "cmpart" does not exist
+CREATE TABLE cmpart2(f1 text COMPRESSION pglz);
+ALTER TABLE cmpart ATTACH PARTITION cmpart2 FOR VALUES WITH (MODULUS 2, REMAINDER 1);
+ERROR:  relation "cmpart" does not exist
+INSERT INTO cmpart VALUES (repeat('123456789',1004));
+ERROR:  relation "cmpart" does not exist
+LINE 1: INSERT INTO cmpart VALUES (repeat('123456789',1004));
+                    ^
+INSERT INTO cmpart VALUES (repeat('123456789',4004));
+ERROR:  relation "cmpart" does not exist
+LINE 1: INSERT INTO cmpart VALUES (repeat('123456789',4004));
+                    ^
+SELECT pg_column_compression(f1) FROM cmpart;
+ERROR:  relation "cmpart" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmpart;
+                                              ^
+-- test compression with inheritence, error
+CREATE TABLE cminh() INHERITS(cmdata, cmdata1);
+ERROR:  relation "cmdata1" does not exist
+CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
+NOTICE:  merging column "f1" with inherited definition
+ERROR:  column "f1" has a compression method conflict
+DETAIL:  pglz versus lz4
+-- check data is ok
+SELECT length(f1) FROM cmdata;
+ length 
+--------
+  10000
+(1 row)
+
+SELECT length(f1) FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: SELECT length(f1) FROM cmdata1;
+                               ^
+SELECT length(f1) FROM cmmove1;
+ length 
+--------
+  10000
+(1 row)
+
+SELECT length(f1) FROM cmmove2;
+ length 
+--------
+  10000
+(1 row)
+
+SELECT length(f1) FROM cmmove3;
+ length 
+--------
+  10000
+(1 row)
+
+\set HIDE_COMPRESSAM on
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 7204fdb0b4..14f3fa3fc8 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -4898,8 +4898,8 @@ Indexes:
 -- check printing info about access methods
 \dA
 List of access methods
-  Name  | Type  
---------+-------
+  Name  |    Type     
+--------+-------------
  brin   | Index
  btree  | Index
  gin    | Index
@@ -4907,13 +4907,15 @@ List of access methods
  hash   | Index
  heap   | Table
  heap2  | Table
+ lz4    | Compression
+ pglz   | Compression
  spgist | Index
-(8 rows)
+(10 rows)
 
 \dA *
 List of access methods
-  Name  | Type  
---------+-------
+  Name  |    Type     
+--------+-------------
  brin   | Index
  btree  | Index
  gin    | Index
@@ -4921,8 +4923,10 @@ List of access methods
  hash   | Index
  heap   | Table
  heap2  | Table
+ lz4    | Compression
+ pglz   | Compression
  spgist | Index
-(8 rows)
+(10 rows)
 
 \dA h*
 List of access methods
@@ -4947,32 +4951,36 @@ List of access methods
 
 \dA: extra argument "bar" ignored
 \dA+
-                             List of access methods
-  Name  | Type  |       Handler        |              Description               
---------+-------+----------------------+----------------------------------------
- brin   | Index | brinhandler          | block range index (BRIN) access method
- btree  | Index | bthandler            | b-tree index access method
- gin    | Index | ginhandler           | GIN index access method
- gist   | Index | gisthandler          | GiST index access method
- hash   | Index | hashhandler          | hash index access method
- heap   | Table | heap_tableam_handler | heap table access method
- heap2  | Table | heap_tableam_handler | 
- spgist | Index | spghandler           | SP-GiST index access method
-(8 rows)
+                                List of access methods
+  Name  |    Type     |       Handler        |              Description               
+--------+-------------+----------------------+----------------------------------------
+ brin   | Index       | brinhandler          | block range index (BRIN) access method
+ btree  | Index       | bthandler            | b-tree index access method
+ gin    | Index       | ginhandler           | GIN index access method
+ gist   | Index       | gisthandler          | GiST index access method
+ hash   | Index       | hashhandler          | hash index access method
+ heap   | Table       | heap_tableam_handler | heap table access method
+ heap2  | Table       | heap_tableam_handler | 
+ lz4    | Compression | lz4handler           | lz4 compression access method
+ pglz   | Compression | pglzhandler          | pglz compression access method
+ spgist | Index       | spghandler           | SP-GiST index access method
+(10 rows)
 
 \dA+ *
-                             List of access methods
-  Name  | Type  |       Handler        |              Description               
---------+-------+----------------------+----------------------------------------
- brin   | Index | brinhandler          | block range index (BRIN) access method
- btree  | Index | bthandler            | b-tree index access method
- gin    | Index | ginhandler           | GIN index access method
- gist   | Index | gisthandler          | GiST index access method
- hash   | Index | hashhandler          | hash index access method
- heap   | Table | heap_tableam_handler | heap table access method
- heap2  | Table | heap_tableam_handler | 
- spgist | Index | spghandler           | SP-GiST index access method
-(8 rows)
+                                List of access methods
+  Name  |    Type     |       Handler        |              Description               
+--------+-------------+----------------------+----------------------------------------
+ brin   | Index       | brinhandler          | block range index (BRIN) access method
+ btree  | Index       | bthandler            | b-tree index access method
+ gin    | Index       | ginhandler           | GIN index access method
+ gist   | Index       | gisthandler          | GiST index access method
+ hash   | Index       | hashhandler          | hash index access method
+ heap   | Table       | heap_tableam_handler | heap table access method
+ heap2  | Table       | heap_tableam_handler | 
+ lz4    | Compression | lz4handler           | lz4 compression access method
+ pglz   | Compression | pglzhandler          | pglz compression access method
+ spgist | Index       | spghandler           | SP-GiST index access method
+(10 rows)
 
 \dA+ h*
                      List of access methods
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 12bb67e491..e9c0fc9760 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -114,7 +114,7 @@ test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion tr
 # ----------
 # Another group of parallel tests
 # ----------
-test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain
+test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression
 
 # event triggers cannot run concurrently with any test that runs DDL
 # oidjoins is read-only, though, and should run late for best coverage
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 59b416fd80..4d5577bae3 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -199,6 +199,7 @@ test: partition_aggregate
 test: partition_info
 test: tuplesort
 test: explain
+test: compression
 test: event_trigger
 test: oidjoins
 test: fast_default
diff --git a/src/test/regress/sql/compression.sql b/src/test/regress/sql/compression.sql
new file mode 100644
index 0000000000..450416ecb4
--- /dev/null
+++ b/src/test/regress/sql/compression.sql
@@ -0,0 +1,85 @@
+\set HIDE_COMPRESSAM off
+
+-- test creating table with compression method
+CREATE TABLE cmdata(f1 text COMPRESSION pglz);
+CREATE INDEX idx ON cmdata(f1);
+INSERT INTO cmdata VALUES(repeat('1234567890',1000));
+\d+ cmdata
+
+CREATE TABLE cmdata1(f1 TEXT COMPRESSION lz4);
+INSERT INTO cmdata1 VALUES(repeat('1234567890',1004));
+\d+ cmdata1
+
+-- try setting compression for incompressible data type
+CREATE TABLE cmdata2 (f1 int COMPRESSION pglz);
+
+-- verify stored compression method
+SELECT pg_column_compression(f1) FROM cmdata;
+SELECT pg_column_compression(f1) FROM cmdata1;
+
+-- decompress data slice
+SELECT SUBSTR(f1, 200, 5) FROM cmdata;
+SELECT SUBSTR(f1, 2000, 50) FROM cmdata1;
+
+-- copy with table creation
+SELECT * INTO cmmove1 FROM cmdata;
+SELECT pg_column_compression(f1) FROM cmmove1;
+
+-- update using datum from different table
+CREATE TABLE cmmove2(f1 text COMPRESSION pglz);
+INSERT INTO cmmove2 VALUES (repeat('1234567890',1004));
+SELECT pg_column_compression(f1) FROM cmmove2;
+
+UPDATE cmmove2 SET f1 = cmdata.f1 FROM cmdata;
+SELECT pg_column_compression(f1) FROM cmmove2;
+UPDATE cmmove2 SET f1 = cmdata1.f1 FROM cmdata1;
+SELECT pg_column_compression(f1) FROM cmmove2;
+
+-- copy to existing table
+CREATE TABLE cmmove3(f1 text COMPRESSION pglz);
+INSERT INTO cmmove3 SELECT * FROM cmdata;
+INSERT INTO cmmove3 SELECT * FROM cmdata1;
+SELECT pg_column_compression(f1) FROM cmmove2;
+
+-- test external compressed data
+CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS
+'select array_agg(md5(g::text))::text from generate_series(1, 256) g';
+CREATE TABLE cmdata2 (f1 text COMPRESSION pglz);
+INSERT INTO cmdata2 select large_val() || repeat('a', 4000);
+SELECT pg_column_compression(f1) FROM cmdata2;
+INSERT INTO cmdata1 SELECT * FROM cmdata2;
+SELECT pg_column_compression(f1) FROM cmdata1;
+DROP TABLE cmdata2;
+
+-- test LIKE INCLUDING COMPRESSION
+CREATE TABLE cmdata2 (LIKE cmdata1 INCLUDING COMPRESSION);
+\d+ cmdata2
+
+-- test compression with materialized view
+CREATE MATERIALIZED VIEW mv(x) AS SELECT * FROM cmdata1;
+\d+ mv
+SELECT pg_column_compression(f1) FROM cmdata1;
+SELECT pg_column_compression(x) FROM mv;
+
+-- test compression with partition
+CREATE TABLE cmpart(f1 text COMPRESSION lz4) PARTITION BY HASH(f1);
+CREATE TABLE cmpart1 PARTITION OF cmpart FOR VALUES WITH (MODULUS 2, REMAINDER 0);
+CREATE TABLE cmpart2(f1 text COMPRESSION pglz);
+
+ALTER TABLE cmpart ATTACH PARTITION cmpart2 FOR VALUES WITH (MODULUS 2, REMAINDER 1);
+INSERT INTO cmpart VALUES (repeat('123456789',1004));
+INSERT INTO cmpart VALUES (repeat('123456789',4004));
+SELECT pg_column_compression(f1) FROM cmpart;
+
+-- test compression with inheritence, error
+CREATE TABLE cminh() INHERITS(cmdata, cmdata1);
+CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
+
+-- check data is ok
+SELECT length(f1) FROM cmdata;
+SELECT length(f1) FROM cmdata1;
+SELECT length(f1) FROM cmmove1;
+SELECT length(f1) FROM cmmove2;
+SELECT length(f1) FROM cmmove3;
+
+\set HIDE_COMPRESSAM on
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index 2aa062b2c9..c64b369047 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -307,6 +307,7 @@ sub GenerateFiles
 		HAVE_LIBXML2                                => undef,
 		HAVE_LIBXSLT                                => undef,
 		HAVE_LIBZ                   => $self->{options}->{zlib} ? 1 : undef,
+		HAVE_LIBLZ4                 => undef,
 		HAVE_LINK                   => undef,
 		HAVE_LOCALE_T               => 1,
 		HAVE_LONG_INT_64            => undef,
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index bab4f3adb3..46cac11d39 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -395,6 +395,7 @@ CompositeIOData
 CompositeTypeStmt
 CompoundAffixFlag
 CompressionAlgorithm
+CompressionAmRoutine
 CompressorState
 ComputeXidHorizonsResult
 ConditionVariable
-- 
2.17.0

  [text/x-diff] v24-0002-psql-Add-HIDE_COMPRESSAM-for-regress-testing.patch (4.3K, ../20210214184940.GL1793@telsasoft.com/3-v24-0002-psql-Add-HIDE_COMPRESSAM-for-regress-testing.patch)
  download | inline diff:
From cc36d0fdd8bbed4887d902ba592a15e29b72c44e Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryzbyj@telsasoft.com>
Date: Sat, 13 Feb 2021 20:48:51 -0600
Subject: [PATCH v24 2/7] psql: Add HIDE_COMPRESSAM for regress testing

This avoids churn in regression output, and allows testing with alternate
compression AMs.
---
 doc/src/sgml/ref/psql-ref.sgml     | 11 +++++++++++
 src/bin/psql/describe.c            |  1 +
 src/bin/psql/help.c                |  2 ++
 src/bin/psql/settings.h            |  1 +
 src/bin/psql/startup.c             |  9 +++++++++
 src/test/regress/pg_regress_main.c |  4 ++--
 6 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 13c1edfa4d..66dcb1b33b 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -3863,6 +3863,17 @@ bar
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><varname>HIDE_COMPRESSAM</varname></term>
+        <listitem>
+        <para>
+         If this variable is set to <literal>true</literal>, column's
+         compression access method details are not displayed. This is mainly
+         useful for regression tests.
+        </para>
+        </listitem>
+      </varlistentry>
+
       <varlistentry>
         <term><varname>HIDE_TABLEAM</varname></term>
         <listitem>
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ba464d463e..b835b0cf76 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1897,6 +1897,7 @@ describeOneTableDetails(const char *schemaname,
 
 		/* compresssion info */
 		if (pset.sversion >= 140000 &&
+			!pset.hide_compressam &&
 			(tableinfo.relkind == RELKIND_RELATION ||
 			 tableinfo.relkind == RELKIND_PARTITIONED_TABLE ||
 			 tableinfo.relkind == RELKIND_MATVIEW))
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index e44120bf76..a818ee5503 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -375,6 +375,8 @@ helpVariables(unsigned short int pager)
 					  "    true if last query failed, else false\n"));
 	fprintf(output, _("  FETCH_COUNT\n"
 					  "    the number of result rows to fetch and display at a time (0 = unlimited)\n"));
+	fprintf(output, _("  HIDE_COMPRESSAM\n"
+					  "    if set, compression access methods are not displayed\n"));
 	fprintf(output, _("  HIDE_TABLEAM\n"
 					  "    if set, table access methods are not displayed\n"));
 	fprintf(output, _("  HISTCONTROL\n"
diff --git a/src/bin/psql/settings.h b/src/bin/psql/settings.h
index d65990059d..9755e8eac6 100644
--- a/src/bin/psql/settings.h
+++ b/src/bin/psql/settings.h
@@ -134,6 +134,7 @@ typedef struct _psqlSettings
 	bool		quiet;
 	bool		singleline;
 	bool		singlestep;
+	bool		hide_compressam;
 	bool		hide_tableam;
 	int			fetch_count;
 	int			histsize;
diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 780479c8d7..554b64367d 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -1159,6 +1159,12 @@ show_context_hook(const char *newval)
 	return true;
 }
 
+static bool
+hide_compressam_hook(const char *newval)
+{
+	return ParseVariableBool(newval, "HIDE_COMPRESSAM", &pset.hide_compressam);
+}
+
 static bool
 hide_tableam_hook(const char *newval)
 {
@@ -1227,6 +1233,9 @@ EstablishVariableSpace(void)
 	SetVariableHooks(pset.vars, "SHOW_CONTEXT",
 					 show_context_substitute_hook,
 					 show_context_hook);
+	SetVariableHooks(pset.vars, "HIDE_COMPRESSAM",
+					 bool_substitute_hook,
+					 hide_compressam_hook);
 	SetVariableHooks(pset.vars, "HIDE_TABLEAM",
 					 bool_substitute_hook,
 					 hide_tableam_hook);
diff --git a/src/test/regress/pg_regress_main.c b/src/test/regress/pg_regress_main.c
index 8dc4941c24..07fd3f6a4d 100644
--- a/src/test/regress/pg_regress_main.c
+++ b/src/test/regress/pg_regress_main.c
@@ -78,11 +78,11 @@ psql_start_test(const char *testname,
 	 * against different AMs without unnecessary differences.
 	 */
 	offset += snprintf(psql_cmd + offset, sizeof(psql_cmd) - offset,
-					   "\"%s%spsql\" -X -a -q -d \"%s\" -v %s < \"%s\" > \"%s\" 2>&1",
+					   "\"%s%spsql\" -X -a -q -d \"%s\" %s < \"%s\" > \"%s\" 2>&1",
 					   bindir ? bindir : "",
 					   bindir ? "/" : "",
 					   dblist->str,
-					   "HIDE_TABLEAM=\"on\"",
+					   "-v HIDE_TABLEAM=on -v HIDE_COMPRESSAM=on",
 					   infile,
 					   outfile);
 	if (offset >= sizeof(psql_cmd))
-- 
2.17.0

  [text/x-diff] v24-0003-Add-default_toast_compression-GUC.patch (10.4K, ../20210214184940.GL1793@telsasoft.com/4-v24-0003-Add-default_toast_compression-GUC.patch)
  download | inline diff:
From bfec3954dee86ffc2c4cbc7a69dd79489309901c Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryzbyj@telsasoft.com>
Date: Fri, 29 Jan 2021 21:37:46 -0600
Subject: [PATCH v24 3/7] Add default_toast_compression GUC

---
 src/backend/access/common/tupdesc.c |   2 +-
 src/backend/bootstrap/bootstrap.c   |   3 +-
 src/backend/commands/amcmds.c       | 143 +++++++++++++++++++++++++++-
 src/backend/commands/tablecmds.c    |   4 +-
 src/backend/utils/init/postinit.c   |   4 +
 src/backend/utils/misc/guc.c        |  12 +++
 src/include/access/amapi.h          |   2 +
 src/include/access/compressamapi.h  |  12 ++-
 8 files changed, 176 insertions(+), 6 deletions(-)

diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index ca26fab487..7afaea000b 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -668,7 +668,7 @@ TupleDescInitEntry(TupleDesc desc,
 	att->attcollation = typeForm->typcollation;
 
 	if (IsStorageCompressible(typeForm->typstorage))
-		att->attcompression = DefaultCompressionOid;
+		att->attcompression = GetDefaultToastCompression();
 	else
 		att->attcompression = InvalidOid;
 
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 9b451eaa71..ec3376cf8a 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -732,8 +732,9 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 	attrtypes[attnum]->attcacheoff = -1;
 	attrtypes[attnum]->atttypmod = -1;
 	attrtypes[attnum]->attislocal = true;
+
 	if (IsStorageCompressible(attrtypes[attnum]->attstorage))
-		attrtypes[attnum]->attcompression = DefaultCompressionOid;
+		attrtypes[attnum]->attcompression = GetDefaultToastCompression();
 	else
 		attrtypes[attnum]->attcompression = InvalidOid;
 
diff --git a/src/backend/commands/amcmds.c b/src/backend/commands/amcmds.c
index 3ad4a61739..1682afd2a4 100644
--- a/src/backend/commands/amcmds.c
+++ b/src/backend/commands/amcmds.c
@@ -13,8 +13,11 @@
  */
 #include "postgres.h"
 
+#include "access/amapi.h"
+#include "access/compressamapi.h"
 #include "access/htup_details.h"
 #include "access/table.h"
+#include "access/xact.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
 #include "catalog/indexing.h"
@@ -27,13 +30,20 @@
 #include "parser/parse_func.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/guc.h"
+#include "utils/inval.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 
-
 static Oid	lookup_am_handler_func(List *handler_name, char amtype);
 static const char *get_am_type_string(char amtype);
 
+/* Compile-time default */
+char	*default_toast_compression = DEFAULT_TOAST_COMPRESSION; // maybe needs pg_dump support ?
+/* Invalid means need to lookup the text value in the catalog */
+static Oid	default_toast_compression_oid = InvalidOid;
+
+static void AccessMethodCallback(Datum arg, int cacheid, uint32 hashvalue);
 
 /*
  * CreateAccessMethod
@@ -277,3 +287,134 @@ lookup_am_handler_func(List *handler_name, char amtype)
 
 	return handlerOid;
 }
+
+/* check_hook: validate new default_toast_compression */
+bool
+check_default_toast_compression(char **newval, void **extra, GucSource source)
+{
+	if (**newval == '\0')
+	{
+		GUC_check_errdetail("%s cannot be empty.",
+							"default_toast_compression");
+		return false;
+	}
+
+	if (strlen(*newval) >= NAMEDATALEN)
+	{
+		GUC_check_errdetail("%s is too long (maximum %d characters).",
+							"default_toast_compression", NAMEDATALEN - 1);
+		return false;
+	}
+
+	/*
+	 * If we aren't inside a transaction, or not connected to a database, we
+	 * cannot do the catalog access necessary to verify the method.  Must
+	 * accept the value on faith.
+	 */
+	if (IsTransactionState() && MyDatabaseId != InvalidOid)
+	{
+		if (!OidIsValid(get_compression_am_oid(*newval, true)))
+		{
+			/*
+			 * When source == PGC_S_TEST, don't throw a hard error for a
+			 * nonexistent table access method, only a NOTICE. See comments in
+			 * guc.h.
+			 */
+			if (source == PGC_S_TEST)
+			{
+				ereport(NOTICE,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("compression access method \"%s\" does not exist",
+								*newval)));
+			}
+			else
+			{
+				GUC_check_errdetail("Compression access method \"%s\" does not exist.",
+									*newval);
+				return false;
+			}
+		}
+	}
+
+	return true;
+}
+
+/*
+ * assign_default_toast_compression: GUC assign_hook for default_toast_compression
+ */
+void
+assign_default_toast_compression(const char *newval, void *extra)
+{
+	/*
+	 * Invalidate setting, forcing it to be looked up as needed.
+	 * This avoids trying to do database access during GUC initialization,
+	 * or outside a transaction.
+	 */
+
+	default_toast_compression = NULL;
+fprintf(stderr, "set to null\n");
+}
+
+
+/*
+ * GetDefaultToastCompression -- get the OID of the current toast compression
+ *
+ * This exists to hide and optimize the use of the default_toast_compression
+ * GUC variable.
+ */
+Oid
+GetDefaultToastCompression(void)
+{
+	/* Avoid catalog access during bootstrap, and for default compression */
+	if (strcmp(default_toast_compression, DEFAULT_TOAST_COMPRESSION) == 0)
+		return PGLZ_COMPRESSION_AM_OID;
+
+	/* Cannot call get_compression_am_oid this early */
+	// if (IsBootstrapProcessingMode())
+		// return PGLZ_COMPRESSION_AM_OID;
+	Assert(!IsBootstrapProcessingMode());
+
+	/*
+	 * If cached value isn't valid, look up the current default value, caching
+	 * the result
+	 */
+	if (!OidIsValid(default_toast_compression_oid))
+		default_toast_compression_oid =
+			get_am_type_oid(default_toast_compression, AMTYPE_COMPRESSION,
+					false);
+
+	return default_toast_compression_oid;
+}
+
+/*
+ * InitializeAccessMethods: initialize module during InitPostgres.
+ *
+ * This is called after we are up enough to be able to do catalog lookups.
+ */
+void
+InitializeAccessMethods(void)
+{
+	if (IsBootstrapProcessingMode())
+		return;
+
+	/*
+	 * In normal mode, arrange for a callback on any syscache invalidation
+	 * of pg_am rows.
+	 */
+	CacheRegisterSyscacheCallback(AMOID,
+								  AccessMethodCallback,
+								  (Datum) 0);
+	/* Force cached default access method to be recomputed on next use */
+	// default_toast_compression_oid = InvalidOid;
+}
+
+/*
+ * AccessMethodCallback
+ *		Syscache inval callback function
+ */
+static void
+AccessMethodCallback(Datum arg, int cacheid, uint32 hashvalue)
+{
+	/* Force look up of compression oid on next use */
+	default_toast_compression_oid = false;
+}
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index dd81d5bf4e..72ba017814 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -11925,7 +11925,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 		if (!IsStorageCompressible(tform->typstorage))
 			attTup->attcompression = InvalidOid;
 		else if (!OidIsValid(attTup->attcompression))
-			attTup->attcompression = DefaultCompressionOid;
+			attTup->attcompression = GetDefaultToastCompression();
 	}
 	else
 		attTup->attcompression = InvalidOid;
@@ -17762,7 +17762,7 @@ GetAttributeCompression(Form_pg_attribute att, char *compression)
 
 	/* fallback to default compression if it's not specified */
 	if (compression == NULL)
-		return DefaultCompressionOid;
+		return GetDefaultToastCompression();
 
 	amoid = get_compression_am_oid(compression, false);
 
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index e5965bc517..6a02bbd377 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -25,6 +25,7 @@
 #include "access/session.h"
 #include "access/sysattr.h"
 #include "access/tableam.h"
+#include "access/amapi.h"
 #include "access/xact.h"
 #include "access/xlog.h"
 #include "catalog/catalog.h"
@@ -1060,6 +1061,9 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 	/* set default namespace search path */
 	InitializeSearchPath();
 
+	/* set callback for changes to pg_am */
+	InitializeAccessMethods();
+
 	/* initialize client encoding */
 	InitializeClientEncoding();
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index eafdb1118e..3a2b33fcd1 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -30,6 +30,7 @@
 #include <unistd.h>
 
 #include "access/commit_ts.h"
+#include "access/compressamapi.h"
 #include "access/gin.h"
 #include "access/rmgr.h"
 #include "access/tableam.h"
@@ -3915,6 +3916,17 @@ static struct config_string ConfigureNamesString[] =
 		check_default_table_access_method, NULL, NULL
 	},
 
+	{
+		{"default_toast_compression", PGC_USERSET, CLIENT_CONN_STATEMENT,
+			gettext_noop("Sets the default compression for new columns."),
+			NULL,
+			GUC_IS_NAME
+		},
+		&default_toast_compression,
+		DEFAULT_TOAST_COMPRESSION,
+		check_default_toast_compression, assign_default_toast_compression, NULL, NULL
+	},
+
 	{
 		{"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
 			gettext_noop("Sets the default tablespace to create tables and indexes in."),
diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index d357ebb559..1513cafcf4 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -287,4 +287,6 @@ typedef struct IndexAmRoutine
 extern IndexAmRoutine *GetIndexAmRoutine(Oid amhandler);
 extern IndexAmRoutine *GetIndexAmRoutineByAmId(Oid amoid, bool noerror);
 
+void InitializeAccessMethods(void);
+
 #endif							/* AMAPI_H */
diff --git a/src/include/access/compressamapi.h b/src/include/access/compressamapi.h
index 5a8e23d926..d75a8e9df2 100644
--- a/src/include/access/compressamapi.h
+++ b/src/include/access/compressamapi.h
@@ -17,6 +17,7 @@
 
 #include "catalog/pg_am_d.h"
 #include "nodes/nodes.h"
+#include "utils/guc.h"
 
 /*
  * Built-in compression method-id.  The toast compression header will store
@@ -29,8 +30,17 @@ typedef enum CompressionId
 	LZ4_COMPRESSION_ID = 1
 } CompressionId;
 
-/* Use default compression method if it is not specified. */
+/* Default compression method if not specified. */
+#define DEFAULT_TOAST_COMPRESSION "pglz"
 #define DefaultCompressionOid	PGLZ_COMPRESSION_AM_OID
+
+/* GUC */
+extern char       *default_toast_compression;
+extern void assign_default_toast_compression(const char *newval, void *extra);
+extern bool check_default_toast_compression(char **newval, void **extra, GucSource source);
+
+extern Oid GetDefaultToastCompression(void);
+
 #define IsStorageCompressible(storage) ((storage) != TYPSTORAGE_PLAIN && \
 										(storage) != TYPSTORAGE_EXTERNAL)
 /* compression handler routines */
-- 
2.17.0

  [text/x-diff] v24-0004-default-to-with-lz4.patch (932B, ../20210214184940.GL1793@telsasoft.com/5-v24-0004-default-to-with-lz4.patch)
  download | inline diff:
From f9b0b50c0b68eb5bc4299747ca0c7d144345cdd9 Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryzbyj@telsasoft.com>
Date: Sat, 13 Feb 2021 22:11:24 -0600
Subject: [PATCH v24 4/7] default to --with-lz4

this is meant to excercize the new feature in the CIs, and not meant to be merged
---
 configure.ac | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 63940b78a0..1fb0f07323 100644
--- a/configure.ac
+++ b/configure.ac
@@ -990,8 +990,8 @@ AC_SUBST(with_zlib)
 # LZ4
 #
 AC_MSG_CHECKING([whether to build with LZ4 support])
-PGAC_ARG_BOOL(with, lz4, no, [build with LZ4 support],
-              [AC_DEFINE([USE_LZ4], 1, [Define to 1 to build with LZ4 support. (--with-lz4)])])
+PGAC_ARG_BOOL(without, lz4, no, [build without LZ4 support],
+              [AC_DEFINE([USE_LZ4], 1, [Define to 1 to build without LZ4 support. (--without-lz4)])])
 AC_SUBST(with_lz4)
 
 #
-- 
2.17.0

  [text/x-diff] v24-0005-fixups.patch.patch (6.4K, ../20210214184940.GL1793@telsasoft.com/6-v24-0005-fixups.patch.patch)
  download | inline diff:
From 5bd3d2b7b19ec40d70d04476a72b765e6a2c2b8c Mon Sep 17 00:00:00 2001
From: Robert Haas <robertmhaas@gmail.com>
Date: Wed, 10 Feb 2021 16:56:17 -0500
Subject: [PATCH v24 5/7] fixups.patch

---
 doc/src/sgml/ddl.sgml                         |  3 ---
 doc/src/sgml/ref/create_table.sgml            | 15 +++++++++++----
 src/backend/access/common/detoast.c           |  5 ++---
 src/backend/access/compression/compress_lz4.c | 10 +++++-----
 src/backend/executor/nodeModifyTable.c        |  2 +-
 src/include/nodes/execnodes.h                 |  4 ++--
 6 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
        <productname>PostgreSQL</productname>
        tables (or, possibly, foreign tables).  It is possible to specify a
        tablespace and storage parameters for each partition separately.
-       By default, each column in a partition inherits the compression method
-       from parent table's column, however a different compression method can be
-       set for each partition.
       </para>
 
       <para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
     <term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
     <listitem>
      <para>
-      This sets the compression method for a column.  The supported compression
-      methods are <literal>pglz</literal> and <literal>lz4</literal>.
-      <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
-      was used when building <productname>PostgreSQL</productname>. The default
+      The <literal>COMPRESSION</literal> clause sets the compression method
+      for a column.  Compression is supported only for variable-width data
+      types, and is used only for columns whose storage type is main or
+      extended. (See <xref linkend="sql-altertable"/> for information on
+      column storage types.) Setting this property for a partitioned table
+      has no direct effect, because such tables have no storage of their own,
+      but the configured value is inherited by newly-created partitions.
+      The supported compression methods are <literal>pglz</literal> and
+      <literal>lz4</literal>.  <literal>lz4</literal> is available only if
+      <literal>--with-lz4</literal> was used when building
+      <productname>PostgreSQL</productname>. The default
       is <literal>pglz</literal>.
      </para>
     </listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
 			return InvalidOid;
 
 		/*
-		 * Just fetch the toast compress header to know the compression method
-		 * in the compressed data.
+		 * Fetch just enough of the value to examine the compression header,
+		 * so that we can find out the compression method.
 		 */
 		attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
 	}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
 
 	cmid = TOAST_COMPRESS_METHOD(attr);
 
-	/* Get the handler routines for the compression method */
 	switch (cmid)
 	{
 		case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
 /*
  * lz4_cmcompress - compression routine for lz4 compression method
  *
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
  * compressed varlena, or NULL if compression fails.
  */
 static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
 	valsize = VARSIZE_ANY_EXHDR(value);
 
 	/*
-	 * Get maximum size of the compressed data that lz4 compression may output
-	 * and allocate the memory for holding the compressed data and the header.
+	 * Figure out the maximum possible size of the LZ4 output, add the bytes
+	 * that will be needed for varlena overhead, and allocate that amount.
 	 */
 	max_size = LZ4_compressBound(valsize);
 	tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
 	int32		rawsize;
 	struct varlena *result;
 
-	/* allocate memory for holding the uncompressed data */
+	/* allocate memory for the uncompressed data */
 	result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
 
-	/* decompress data using lz4 routine */
+	/* decompress the data */
 	rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
 								  VARDATA(result),
 								  VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 		TupleTableSlot *newslot = *outslot;
 
 		/*
-		 * If the called has passed an invalid slot then create a new slot.
+		 * If the caller has passed an invalid slot then create a new slot.
 		 * Otherwise, just clear the existing tuple from the slot.  This slot
 		 * should be stored by the caller so that it can be reused for
 		 * decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
 	TupleTableSlot *mt_root_tuple_slot;
 
 	/*
-	 * Slot for storing the modified tuple, incase the target attribute's
-	 * compression method doesn't match with the source table.
+	 * Slot for storing the modified tuple, in case the target attribute's
+	 * compression method doesn't match that of the source table.
 	 */
 	TupleTableSlot *mt_decompress_tuple_slot;
 
-- 
2.17.0

  [text/x-diff] v24-0006-alter-table-set-compression.patch (29.3K, ../20210214184940.GL1793@telsasoft.com/7-v24-0006-alter-table-set-compression.patch)
  download | inline diff:
From b0788c502b5f7a6733935ec7b81e7fb717741f80 Mon Sep 17 00:00:00 2001
From: dilipkumar <dilipbalaut@gmail.com>
Date: Fri, 18 Dec 2020 11:31:22 +0530
Subject: [PATCH v24 6/7] alter table set compression

Add support for changing the compression method associated
with a column, forcing a table rewrite.

Dilip Kumar based on the patches from Ildus Kurbangaliev.
Design input from Robert Haas and Tomas Vondra.
Reviewed by Robert Haas, Tomas Vondra, Alexander Korotkov

Discussions:
https://www.postgresql.org/message-id/20171213151818.75a20259@postgrespro.ru
https://www.postgresql.org/message-id/CA%2BTgmoaKDW1Oi9V%3Djc9hOGyf77NbkNEABuqgHD1Cq%3D%3D1QsOcxg%40mail.gmail.com
https://www.postgresql.org/message-id/CA%2BTgmobSDVgUage9qQ5P_%3DF_9jaMkCgyKxUQGtFQU7oN4kX-AA%40mail.gmail.com
https://www.postgresql.org/message-id/20201005160355.byp74sh3ejsv7wrj%40development
https://www.postgresql.org/message-id/CAFiTN-tzTTT2oqWdRGLv1dvvS5MC1W%2BLE%2B3bqWPJUZj4GnHOJg%40mail.gmail.com
---
 doc/src/sgml/ref/alter_table.sgml           |  16 ++
 src/backend/commands/createas.c             |   3 +-
 src/backend/commands/matview.c              |   3 +-
 src/backend/commands/tablecmds.c            | 226 +++++++++++++++-----
 src/backend/executor/nodeModifyTable.c      |   9 +-
 src/backend/parser/gram.y                   |   9 +
 src/bin/psql/tab-complete.c                 |   2 +-
 src/include/commands/event_trigger.h        |   1 +
 src/include/executor/executor.h             |   3 +-
 src/include/nodes/parsenodes.h              |   3 +-
 src/test/regress/expected/compression.out   |  93 ++++++--
 src/test/regress/expected/compression_1.out |  56 ++++-
 src/test/regress/sql/compression.sql        |  21 ++
 13 files changed, 370 insertions(+), 75 deletions(-)

diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index c25ef5abd6..0bd0c1a503 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -54,6 +54,7 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable>
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET ( <replaceable class="parameter">attribute_option</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] )
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> RESET ( <replaceable class="parameter">attribute_option</replaceable> [, ... ] )
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
+    ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET COMPRESSION <replaceable class="parameter">compression_method</replaceable>
     ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]
     ADD <replaceable class="parameter">table_constraint_using_index</replaceable>
     ALTER CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
@@ -103,6 +104,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
   GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( <replaceable>sequence_options</replaceable> ) ] |
   UNIQUE <replaceable class="parameter">index_parameters</replaceable> |
   PRIMARY KEY <replaceable class="parameter">index_parameters</replaceable> |
+  COMPRESSION <replaceable class="parameter">compression_method</replaceable> |
   REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ]
     [ ON DELETE <replaceable class="parameter">referential_action</replaceable> ] [ ON UPDATE <replaceable class="parameter">referential_action</replaceable> ] }
 [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
@@ -383,6 +385,20 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term>
+     <literal>SET COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal>
+    </term>
+    <listitem>
+     <para>
+      This sets the compression method for a column.  The supported compression
+      methods are <literal>pglz</literal> and <literal>lz4</literal>.
+      <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
+      was used when building <productname>PostgreSQL</productname>.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><literal>ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]</literal></term>
     <listitem>
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 1d17dc0d6b..748ec29570 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -589,7 +589,8 @@ intorel_receive(TupleTableSlot *slot, DestReceiver *self)
 		 */
 		slot = CompareCompressionMethodAndDecompress(slot,
 													 &myState->decompress_tuple_slot,
-													 myState->rel->rd_att);
+													 myState->rel->rd_att,
+													 NULL);
 
 		/*
 		 * Note that the input slot might not be of the type of the target
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index 713fc3fceb..779b4e51cf 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -494,7 +494,8 @@ transientrel_receive(TupleTableSlot *slot, DestReceiver *self)
 	 */
 	slot = CompareCompressionMethodAndDecompress(slot,
 												 &myState->decompress_tuple_slot,
-												 myState->transientrel->rd_att);
+												 myState->transientrel->rd_att,
+												 NULL);
 
 	/*
 	 * Note that the input slot might not be of the type of the target
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 72ba017814..586a92f0c1 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -529,6 +529,8 @@ static void ATExecGenericOptions(Relation rel, List *options);
 static void ATExecEnableRowSecurity(Relation rel);
 static void ATExecDisableRowSecurity(Relation rel);
 static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls);
+static ObjectAddress ATExecSetCompression(AlteredTableInfo *tab, Relation rel,
+					 const char *column, Node *newValue, LOCKMODE lockmode);
 
 static void index_copy_data(Relation rel, RelFileNode newrnode);
 static const char *storage_name(char c);
@@ -3968,6 +3970,7 @@ AlterTableGetLockLevel(List *cmds)
 				 */
 			case AT_GenericOptions:
 			case AT_AlterColumnGenericOptions:
+			case AT_SetCompression:
 				cmd_lockmode = AccessExclusiveLock;
 				break;
 
@@ -4495,7 +4498,8 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 		case AT_DisableRowSecurity:
 		case AT_ForceRowSecurity:
 		case AT_NoForceRowSecurity:
-			ATSimplePermissions(rel, ATT_TABLE);
+		case AT_SetCompression:
+			ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW);
 			/* These commands never recurse */
 			/* No command-specific prep needed */
 			pass = AT_PASS_MISC;
@@ -4903,6 +4907,10 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			Assert(rel->rd_rel->relkind == RELKIND_INDEX);
 			ATExecAlterCollationRefreshVersion(rel, cmd->object);
 			break;
+		case AT_SetCompression:
+			address = ATExecSetCompression(tab, rel, cmd->name, cmd->def,
+										   lockmode);
+			break;
 		default:				/* oops */
 			elog(ERROR, "unrecognized alter table type: %d",
 				 (int) cmd->subtype);
@@ -5519,6 +5527,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 
 		while (table_scan_getnextslot(scan, ForwardScanDirection, oldslot))
 		{
+			bool		decompressed = false;
 			TupleTableSlot *insertslot;
 
 			if (tab->rewrite > 0)
@@ -5527,11 +5536,25 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 				slot_getallattrs(oldslot);
 				ExecClearTuple(newslot);
 
-				/* copy attributes */
-				memcpy(newslot->tts_values, oldslot->tts_values,
-					   sizeof(Datum) * oldslot->tts_nvalid);
-				memcpy(newslot->tts_isnull, oldslot->tts_isnull,
-					   sizeof(bool) * oldslot->tts_nvalid);
+				if (tab->rewrite & AT_REWRITE_ALTER_COMPRESSION)
+					(void) CompareCompressionMethodAndDecompress(oldslot,
+																 &newslot,
+																 newTupDesc,
+																 &decompressed);
+
+				/*
+				 * copy attributes, if we have decompressed some attribute then
+				 * the values and nulls array is already copied
+				 */
+				if (!decompressed)
+				{
+					memcpy(newslot->tts_values, oldslot->tts_values,
+						   sizeof(Datum) * oldslot->tts_nvalid);
+					memcpy(newslot->tts_isnull, oldslot->tts_isnull,
+						   sizeof(bool) * oldslot->tts_nvalid);
+				}
+				else
+					ExecClearTuple(newslot);
 
 				/* Set dropped attributes to null in new tuple */
 				foreach(lc, dropped_attrs)
@@ -7767,6 +7790,67 @@ ATExecSetOptions(Relation rel, const char *colName, Node *options,
 	return address;
 }
 
+/*
+ * Helper function for ATExecSetStorage and ATExecSetCompression
+ *
+ * Set the attcompression and attstorage for the respective index attribute if
+ * the respective input values are valid.
+ */
+static void
+ApplyChangesToIndexes(Relation rel, Relation attrelation, AttrNumber attnum,
+					  Oid newcompression, char newstorage, LOCKMODE lockmode)
+{
+	HeapTuple	tuple;
+	ListCell   *lc;
+	Form_pg_attribute attrtuple;
+
+	foreach(lc, RelationGetIndexList(rel))
+	{
+		Oid			indexoid = lfirst_oid(lc);
+		Relation	indrel;
+		AttrNumber	indattnum = 0;
+
+		indrel = index_open(indexoid, lockmode);
+
+		for (int i = 0; i < indrel->rd_index->indnatts; i++)
+		{
+			if (indrel->rd_index->indkey.values[i] == attnum)
+			{
+				indattnum = i + 1;
+				break;
+			}
+		}
+
+		if (indattnum == 0)
+		{
+			index_close(indrel, lockmode);
+			continue;
+		}
+
+		tuple = SearchSysCacheCopyAttNum(RelationGetRelid(indrel), indattnum);
+
+		if (HeapTupleIsValid(tuple))
+		{
+			attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
+
+			if (OidIsValid(newcompression))
+				attrtuple->attcompression = newcompression;
+
+			if (newstorage != '\0')
+				attrtuple->attstorage = newstorage;
+
+			CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+			InvokeObjectPostAlterHook(RelationRelationId,
+									  RelationGetRelid(rel),
+									  attrtuple->attnum);
+
+			heap_freetuple(tuple);
+		}
+
+		index_close(indrel, lockmode);
+	}
+}
 /*
  * ALTER TABLE ALTER COLUMN SET STORAGE
  *
@@ -7782,7 +7866,6 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 	Form_pg_attribute attrtuple;
 	AttrNumber	attnum;
 	ObjectAddress address;
-	ListCell   *lc;
 
 	Assert(IsA(newValue, String));
 	storagemode = strVal(newValue);
@@ -7846,47 +7929,8 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 	 * Apply the change to indexes as well (only for simple index columns,
 	 * matching behavior of index.c ConstructTupleDescriptor()).
 	 */
-	foreach(lc, RelationGetIndexList(rel))
-	{
-		Oid			indexoid = lfirst_oid(lc);
-		Relation	indrel;
-		AttrNumber	indattnum = 0;
-
-		indrel = index_open(indexoid, lockmode);
-
-		for (int i = 0; i < indrel->rd_index->indnatts; i++)
-		{
-			if (indrel->rd_index->indkey.values[i] == attnum)
-			{
-				indattnum = i + 1;
-				break;
-			}
-		}
-
-		if (indattnum == 0)
-		{
-			index_close(indrel, lockmode);
-			continue;
-		}
-
-		tuple = SearchSysCacheCopyAttNum(RelationGetRelid(indrel), indattnum);
-
-		if (HeapTupleIsValid(tuple))
-		{
-			attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
-			attrtuple->attstorage = newstorage;
-
-			CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
-
-			InvokeObjectPostAlterHook(RelationRelationId,
-									  RelationGetRelid(rel),
-									  attrtuple->attnum);
-
-			heap_freetuple(tuple);
-		}
-
-		index_close(indrel, lockmode);
-	}
+	ApplyChangesToIndexes(rel, attrelation, attnum, InvalidOid, newstorage,
+						  lockmode);
 
 	table_close(attrelation, RowExclusiveLock);
 
@@ -15033,6 +15077,92 @@ ATExecGenericOptions(Relation rel, List *options)
 	heap_freetuple(tuple);
 }
 
+/*
+ * ALTER TABLE ALTER COLUMN SET COMPRESSION
+ *
+ * Return value is the address of the modified column
+ */
+static ObjectAddress
+ATExecSetCompression(AlteredTableInfo *tab,
+					 Relation rel,
+					 const char *column,
+					 Node *newValue,
+					 LOCKMODE lockmode)
+{
+	Relation	attrel;
+	HeapTuple	tuple;
+	Form_pg_attribute atttableform;
+	AttrNumber	attnum;
+	char	   *compression;
+	char		typstorage;
+	Oid			cmoid;
+	Datum		values[Natts_pg_attribute];
+	bool		nulls[Natts_pg_attribute];
+	bool		replace[Natts_pg_attribute];
+	ObjectAddress address;
+
+	Assert(IsA(newValue, String));
+	compression = strVal(newValue);
+
+	attrel = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheAttName(RelationGetRelid(rel), column);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						column, RelationGetRelationName(rel))));
+
+	/* Prevent them from altering a system attribute */
+	atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = atttableform->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"", column)));
+
+	typstorage = get_typstorage(atttableform->atttypid);
+
+	/* Prevent from setting compression methods for uncompressible type */
+	if (!IsStorageCompressible(typstorage))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					errmsg("column data type %s does not support compression",
+						format_type_be(atttableform->atttypid))));
+
+	/* Initialize buffers for new tuple values */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+	memset(replace, false, sizeof(replace));
+
+	/* Get the attribute compression method. */
+	cmoid = GetAttributeCompression(atttableform, compression);
+
+	if (atttableform->attcompression != cmoid)
+		tab->rewrite |= AT_REWRITE_ALTER_COMPRESSION;
+
+	atttableform->attcompression = cmoid;
+	CatalogTupleUpdate(attrel, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  atttableform->attnum);
+
+	ReleaseSysCache(tuple);
+
+	/* apply changes to the index column as well */
+	ApplyChangesToIndexes(rel, attrel, attnum, cmoid, '\0', lockmode);
+	table_close(attrel, RowExclusiveLock);
+
+	/* make changes visible */
+	CommandCounterIncrement();
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), atttableform->attnum);
+	return address;
+}
+
+
 /*
  * Preparation phase for SET LOGGED/UNLOGGED
  *
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index 920d9dd0d5..ea82a05591 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2052,7 +2052,8 @@ ExecPrepareTupleRouting(ModifyTableState *mtstate,
 TupleTableSlot *
 CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 									  TupleTableSlot **outslot,
-									  TupleDesc targetTupDesc)
+									  TupleDesc targetTupDesc,
+									  bool *decompressed)
 {
 	int			i;
 	int			attnum;
@@ -2139,6 +2140,9 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 
 		*outslot = newslot;
 
+		if (decompressed != NULL)
+			*decompressed = true;
+
 		return newslot;
 	}
 
@@ -2360,7 +2364,8 @@ ExecModifyTable(PlanState *pstate)
 		 */
 		slot = CompareCompressionMethodAndDecompress(slot,
 									&node->mt_decompress_tuple_slot,
-									resultRelInfo->ri_RelationDesc->rd_att);
+									resultRelInfo->ri_RelationDesc->rd_att,
+									NULL);
 
 		switch (operation)
 		{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 52d92df25d..30acfe615d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2308,6 +2308,15 @@ alter_table_cmd:
 					n->missing_ok = true;
 					$$ = (Node *)n;
 				}
+			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET (COMPRESSION <cm>) */
+			| ALTER opt_column ColId SET optColumnCompression
+				{
+					AlterTableCmd *n = makeNode(AlterTableCmd);
+					n->subtype = AT_SetCompression;
+					n->name = $3;
+					n->def = (Node *) makeString($5);
+					$$ = (Node *)n;
+				}
 			/* ALTER TABLE <name> DROP [COLUMN] IF EXISTS <colname> [RESTRICT|CASCADE] */
 			| DROP opt_column IF_P EXISTS ColId opt_drop_behavior
 				{
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 1e1c315bae..ffa8d05edf 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2098,7 +2098,7 @@ psql_completion(const char *text, int start, int end)
 	/* ALTER TABLE ALTER [COLUMN] <foo> SET */
 	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET") ||
 			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET"))
-		COMPLETE_WITH("(", "DEFAULT", "NOT NULL", "STATISTICS", "STORAGE");
+		COMPLETE_WITH("(", "COMPRESSION", "DEFAULT", "NOT NULL", "STATISTICS", "STORAGE");
 	/* ALTER TABLE ALTER [COLUMN] <foo> SET ( */
 	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET", "(") ||
 			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET", "("))
diff --git a/src/include/commands/event_trigger.h b/src/include/commands/event_trigger.h
index c11bf2d781..5a314f4c1d 100644
--- a/src/include/commands/event_trigger.h
+++ b/src/include/commands/event_trigger.h
@@ -32,6 +32,7 @@ typedef struct EventTriggerData
 #define AT_REWRITE_ALTER_PERSISTENCE	0x01
 #define AT_REWRITE_DEFAULT_VAL			0x02
 #define AT_REWRITE_COLUMN_REWRITE		0x04
+#define AT_REWRITE_ALTER_COMPRESSION	0x08
 
 /*
  * EventTriggerData is the node type that is passed as fmgr "context" info
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 6495162a33..050ef2dcd0 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -623,5 +623,6 @@ extern void CheckSubscriptionRelkind(char relkind, const char *nspname,
 									 const char *relname);
 extern TupleTableSlot *CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 												  TupleTableSlot **outslot,
-												  TupleDesc targetTupDesc);
+												  TupleDesc targetTupDesc,
+												  bool *decompressed);
 #endif							/* EXECUTOR_H  */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 19d2ba26bf..f9a87dee02 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1901,7 +1901,8 @@ typedef enum AlterTableType
 	AT_AddIdentity,				/* ADD IDENTITY */
 	AT_SetIdentity,				/* SET identity column options */
 	AT_DropIdentity,			/* DROP IDENTITY */
-	AT_AlterCollationRefreshVersion /* ALTER COLLATION ... REFRESH VERSION */
+	AT_AlterCollationRefreshVersion, /* ALTER COLLATION ... REFRESH VERSION */
+	AT_SetCompression			/* SET COMPRESSION */
 } AlterTableType;
 
 typedef struct ReplicaIdentityStmt
diff --git a/src/test/regress/expected/compression.out b/src/test/regress/expected/compression.out
index 167878e78b..21c1b451d2 100644
--- a/src/test/regress/expected/compression.out
+++ b/src/test/regress/expected/compression.out
@@ -4,20 +4,20 @@ CREATE TABLE cmdata(f1 text COMPRESSION pglz);
 CREATE INDEX idx ON cmdata(f1);
 INSERT INTO cmdata VALUES(repeat('1234567890',1000));
 \d+ cmdata
-                                 Table "public.cmdata"
- Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
---------+------+-----------+----------+---------+----------+--------------+-------------
- f1     | text |           |          |         | extended |              | 
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
 Indexes:
     "idx" btree (f1)
 
 CREATE TABLE cmdata1(f1 TEXT COMPRESSION lz4);
 INSERT INTO cmdata1 VALUES(repeat('1234567890',1004));
 \d+ cmdata1
-                                 Table "public.cmdata1"
- Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
---------+------+-----------+----------+---------+----------+--------------+-------------
- f1     | text |           |          |         | extended |              | 
+                                        Table "public.cmdata1"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | lz4         |              | 
 
 -- try setting compression for incompressible data type
 CREATE TABLE cmdata2 (f1 int COMPRESSION pglz);
@@ -112,18 +112,18 @@ DROP TABLE cmdata2;
 -- test LIKE INCLUDING COMPRESSION
 CREATE TABLE cmdata2 (LIKE cmdata1 INCLUDING COMPRESSION);
 \d+ cmdata2
-                                 Table "public.cmdata2"
- Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
---------+------+-----------+----------+---------+----------+--------------+-------------
- f1     | text |           |          |         | extended |              | 
+                                        Table "public.cmdata2"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | lz4         |              | 
 
 -- test compression with materialized view
 CREATE MATERIALIZED VIEW mv(x) AS SELECT * FROM cmdata1;
 \d+ mv
-                             Materialized view "public.mv"
- Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
---------+------+-----------+----------+---------+----------+--------------+-------------
- x      | text |           |          |         | extended |              | 
+                                    Materialized view "public.mv"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ x      | text |           |          |         | extended | pglz        |              | 
 View definition:
  SELECT cmdata1.f1 AS x
    FROM cmdata1;
@@ -165,6 +165,67 @@ CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
 NOTICE:  merging column "f1" with inherited definition
 ERROR:  column "f1" has a compression method conflict
 DETAIL:  pglz versus lz4
+-- test alter compression method with rewrite
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | lz4         |              | 
+Indexes:
+    "idx" btree (f1)
+
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+-- test alter compression method for the materialized view
+ALTER TABLE cmdata1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER MATERIALIZED VIEW mv ALTER COLUMN x SET COMPRESSION lz4;
+REFRESH MATERIALIZED VIEW mv;
+\d+ mv
+                                    Materialized view "public.mv"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ x      | text |           |          |         | extended | lz4         |              | 
+View definition:
+ SELECT cmdata1.f1 AS x
+   FROM cmdata1;
+
+SELECT pg_column_compression(f1) FROM cmdata1;
+ pg_column_compression 
+-----------------------
+ pglz
+ pglz
+(2 rows)
+
+SELECT pg_column_compression(x) FROM mv;
+ pg_column_compression 
+-----------------------
+ lz4
+ lz4
+(2 rows)
+
+-- test alter compression method for the partitioned table
+ALTER TABLE cmpart ALTER COLUMN f1 SET COMPRESSION pglz;
+SELECT pg_column_compression(f1) FROM cmpart;
+ pg_column_compression 
+-----------------------
+ lz4
+ pglz
+(2 rows)
+
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+SELECT pg_column_compression(f1) FROM cmpart;
+ pg_column_compression 
+-----------------------
+ pglz
+ lz4
+(2 rows)
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
diff --git a/src/test/regress/expected/compression_1.out b/src/test/regress/expected/compression_1.out
index 329e7881b0..64c5855bf7 100644
--- a/src/test/regress/expected/compression_1.out
+++ b/src/test/regress/expected/compression_1.out
@@ -4,10 +4,10 @@ CREATE TABLE cmdata(f1 text COMPRESSION pglz);
 CREATE INDEX idx ON cmdata(f1);
 INSERT INTO cmdata VALUES(repeat('1234567890',1000));
 \d+ cmdata
-                                 Table "public.cmdata"
- Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
---------+------+-----------+----------+---------+----------+--------------+-------------
- f1     | text |           |          |         | extended |              | 
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
 Indexes:
     "idx" btree (f1)
 
@@ -157,6 +157,54 @@ CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
 NOTICE:  merging column "f1" with inherited definition
 ERROR:  column "f1" has a compression method conflict
 DETAIL:  pglz versus lz4
+-- test alter compression method with rewrite
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
+ERROR:  not built with lz4 support
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
+Indexes:
+    "idx" btree (f1)
+
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- test alter compression method for the materialized view
+ALTER TABLE cmdata1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ERROR:  relation "cmdata1" does not exist
+ALTER MATERIALIZED VIEW mv ALTER COLUMN x SET COMPRESSION lz4;
+ERROR:  relation "mv" does not exist
+REFRESH MATERIALIZED VIEW mv;
+ERROR:  relation "mv" does not exist
+\d+ mv
+SELECT pg_column_compression(f1) FROM cmdata1;
+ERROR:  relation "cmdata1" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmdata1;
+                                              ^
+SELECT pg_column_compression(x) FROM mv;
+ERROR:  relation "mv" does not exist
+LINE 1: SELECT pg_column_compression(x) FROM mv;
+                                             ^
+-- test alter compression method for the partitioned table
+ALTER TABLE cmpart ALTER COLUMN f1 SET COMPRESSION pglz;
+ERROR:  relation "cmpart" does not exist
+SELECT pg_column_compression(f1) FROM cmpart;
+ERROR:  relation "cmpart" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmpart;
+                                              ^
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ERROR:  relation "cmpart1" does not exist
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+ERROR:  not built with lz4 support
+SELECT pg_column_compression(f1) FROM cmpart;
+ERROR:  relation "cmpart" does not exist
+LINE 1: SELECT pg_column_compression(f1) FROM cmpart;
+                                              ^
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
diff --git a/src/test/regress/sql/compression.sql b/src/test/regress/sql/compression.sql
index 450416ecb4..b9daa33b74 100644
--- a/src/test/regress/sql/compression.sql
+++ b/src/test/regress/sql/compression.sql
@@ -75,6 +75,27 @@ SELECT pg_column_compression(f1) FROM cmpart;
 CREATE TABLE cminh() INHERITS(cmdata, cmdata1);
 CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata);
 
+-- test alter compression method with rewrite
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
+\d+ cmdata
+SELECT pg_column_compression(f1) FROM cmdata;
+
+-- test alter compression method for the materialized view
+ALTER TABLE cmdata1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER MATERIALIZED VIEW mv ALTER COLUMN x SET COMPRESSION lz4;
+REFRESH MATERIALIZED VIEW mv;
+\d+ mv
+SELECT pg_column_compression(f1) FROM cmdata1;
+SELECT pg_column_compression(x) FROM mv;
+
+-- test alter compression method for the partitioned table
+ALTER TABLE cmpart ALTER COLUMN f1 SET COMPRESSION pglz;
+SELECT pg_column_compression(f1) FROM cmpart;
+
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+SELECT pg_column_compression(f1) FROM cmpart;
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
 SELECT length(f1) FROM cmdata1;
-- 
2.17.0

  [text/x-diff] v24-0007-Add-support-for-PRESERVE.patch (52.4K, ../20210214184940.GL1793@telsasoft.com/8-v24-0007-Add-support-for-PRESERVE.patch)
  download | inline diff:
From 34436a06ec53febcf7bf49ca7e1a82f21a5bc55a Mon Sep 17 00:00:00 2001
From: Dilip Kumar <dilipkumar@localhost.localdomain>
Date: Wed, 10 Feb 2021 11:49:23 +0530
Subject: [PATCH v24 7/7] Add support for PRESERVE
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Now the compression method can be changed without forcing a table
rewrite, by including the old method in the PRESERVE list.  For
supporting this the column will maintain the dependency with all
the supported compression methods.  So whenever the compression
method is altered the dependency is added with the new compression
method and the dependency is removed for all the old compression
methods which are not given in the preserve list.  If PRESERVE ALL
is given then all the dependency is maintained.

Dilip Kumar based on the patches from Ildus Kurbangaliev.
Design input from Tomas Vondra and Robert Haas
Reviewed by Robert Haas, Tomas Vondra, Alexander Korotkov and Justin Pryzby
---
 doc/src/sgml/ref/alter_table.sgml           |  10 +-
 src/backend/catalog/pg_depend.c             |   7 +
 src/backend/commands/Makefile               |   1 +
 src/backend/commands/compressioncmds.c      | 300 ++++++++++++++++++++
 src/backend/commands/tablecmds.c            | 126 ++++----
 src/backend/executor/nodeModifyTable.c      |  12 +-
 src/backend/nodes/copyfuncs.c               |  17 +-
 src/backend/nodes/equalfuncs.c              |  15 +-
 src/backend/nodes/outfuncs.c                |  15 +-
 src/backend/parser/gram.y                   |  52 +++-
 src/backend/parser/parse_utilcmd.c          |   2 +-
 src/bin/pg_dump/pg_dump.c                   | 101 +++++++
 src/bin/pg_dump/pg_dump.h                   |  15 +-
 src/bin/psql/tab-complete.c                 |   7 +
 src/include/commands/defrem.h               |   7 +
 src/include/commands/tablecmds.h            |   2 +
 src/include/nodes/nodes.h                   |   1 +
 src/include/nodes/parsenodes.h              |  16 +-
 src/test/regress/expected/compression.out   |  37 ++-
 src/test/regress/expected/compression_1.out |  39 ++-
 src/test/regress/expected/create_index.out  |  56 ++--
 src/test/regress/sql/compression.sql        |   9 +
 22 files changed, 739 insertions(+), 108 deletions(-)
 create mode 100644 src/backend/commands/compressioncmds.c

diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index 0bd0c1a503..c9f443a59c 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -54,7 +54,7 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable>
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET ( <replaceable class="parameter">attribute_option</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] )
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> RESET ( <replaceable class="parameter">attribute_option</replaceable> [, ... ] )
     ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
-    ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET COMPRESSION <replaceable class="parameter">compression_method</replaceable>
+    ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET COMPRESSION <replaceable class="parameter">compression_method</replaceable> [ PRESERVE (<replaceable class="parameter">compression_preserve_list</replaceable>) | PRESERVE ALL ]
     ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]
     ADD <replaceable class="parameter">table_constraint_using_index</replaceable>
     ALTER CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
@@ -387,7 +387,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
 
    <varlistentry>
     <term>
-     <literal>SET COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal>
+     <literal>SET COMPRESSION <replaceable class="parameter">compression_method</replaceable> [ PRESERVE (<replaceable class="parameter">compression_preserve_list</replaceable>) | PRESERVE ALL ]</literal>
     </term>
     <listitem>
      <para>
@@ -395,6 +395,12 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       methods are <literal>pglz</literal> and <literal>lz4</literal>.
       <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
       was used when building <productname>PostgreSQL</productname>.
+      The <literal>PRESERVE</literal> list contains a list of compression
+      methods used in the column and determines which of them may be kept.
+      Without <literal>PRESERVE</literal> or if any of the pre-existing
+      compression methods are not preserved, the table will be rewritten.  If
+      <literal>PRESERVE ALL</literal> is specified, then all of the existing
+      methods will be preserved and the table will not be rewritten.
      </para>
     </listitem>
    </varlistentry>
diff --git a/src/backend/catalog/pg_depend.c b/src/backend/catalog/pg_depend.c
index 63da24322d..dd376484b7 100644
--- a/src/backend/catalog/pg_depend.c
+++ b/src/backend/catalog/pg_depend.c
@@ -17,6 +17,7 @@
 #include "access/genam.h"
 #include "access/htup_details.h"
 #include "access/table.h"
+#include "catalog/pg_am.h"
 #include "catalog/dependency.h"
 #include "catalog/indexing.h"
 #include "catalog/pg_collation.h"
@@ -125,6 +126,12 @@ recordMultipleDependencies(const ObjectAddress *depender,
 				if (referenced->objectId == DEFAULT_COLLATION_OID)
 					ignore_systempin = true;
 			}
+			/*
+			 * Record the dependency on compression access method for handling
+			 * preserve.
+			 */
+			if (referenced->classId == AccessMethodRelationId)
+				ignore_systempin = true;
 		}
 		else
 			Assert(!version);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index e8504f0ae4..a7395ad77d 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -21,6 +21,7 @@ OBJS = \
 	cluster.o \
 	collationcmds.o \
 	comment.o \
+	compressioncmds.o \
 	constraint.o \
 	conversioncmds.o \
 	copy.o \
diff --git a/src/backend/commands/compressioncmds.c b/src/backend/commands/compressioncmds.c
new file mode 100644
index 0000000000..fd6db24e7f
--- /dev/null
+++ b/src/backend/commands/compressioncmds.c
@@ -0,0 +1,300 @@
+/*-------------------------------------------------------------------------
+ *
+ * compressioncmds.c
+ *	  Routines for SQL commands for attribute compression methods
+ *
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/commands/compressioncmds.c
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/compressamapi.h"
+#include "access/heapam.h"
+#include "access/htup_details.h"
+#include "access/reloptions.h"
+#include "catalog/catalog.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/pg_attribute.h"
+#include "catalog/pg_depend.h"
+#include "commands/defrem.h"
+#include "commands/tablecmds.h"
+#include "miscadmin.h"
+#include "nodes/parsenodes.h"
+#include "utils/builtins.h"
+#include "utils/fmgroids.h"
+#include "utils/lsyscache.h"
+
+/*
+ * Get list of all supported compression methods for the given attribute.
+ *
+ * We maintain dependency of the attribute on the pg_am row for the current
+ * compression AM and all the preserved compression AM.  So scan pg_depend and
+ * find the column dependency on the pg_am.  Collect the list of access method
+ * oids on which this attribute has a dependency.
+ */
+static List *
+lookup_attribute_compression(Oid attrelid, AttrNumber attnum, List *oldcmoids)
+{
+	LOCKMODE	lock = AccessShareLock;
+	HeapTuple	tup;
+	Relation	rel;
+	SysScanDesc scan;
+	ScanKeyData key[3];
+	List	   *cmoids = NIL;
+
+	rel = table_open(DependRelationId, lock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_classid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_objid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(attrelid));
+	ScanKeyInit(&key[2],
+				Anum_pg_depend_objsubid,
+				BTEqualStrategyNumber, F_INT4EQ,
+				Int32GetDatum((int32) attnum));
+
+	scan = systable_beginscan(rel, DependDependerIndexId, true,
+							  NULL, 3, key);
+
+	while (HeapTupleIsValid(tup = systable_getnext(scan)))
+	{
+		Form_pg_depend depform = (Form_pg_depend) GETSTRUCT(tup);
+
+		if (depform->refclassid == AccessMethodRelationId)
+			cmoids = list_append_unique_oid(cmoids, depform->refobjid);
+	}
+
+	systable_endscan(scan);
+	table_close(rel, lock);
+
+	return cmoids;
+}
+
+/*
+ * Remove the attribute dependency on the old compression methods
+ *
+ * Scan the pg_depend and search the attribute dependency on the pg_am.  Remove
+ * dependency on previous am which is not preserved.  The list of non-preserved
+ * AMs is given in cmoids.
+ */
+static void
+remove_old_dependencies(Oid attrelid, AttrNumber attnum, List *cmoids)
+{
+	LOCKMODE	lock = AccessShareLock;
+	HeapTuple	tup;
+	Relation	rel;
+	SysScanDesc scan;
+	ScanKeyData key[3];
+
+	rel = table_open(DependRelationId, lock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_classid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_objid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(attrelid));
+	ScanKeyInit(&key[2],
+				Anum_pg_depend_objsubid,
+				BTEqualStrategyNumber, F_INT4EQ,
+				Int32GetDatum((int32) attnum));
+
+	scan = systable_beginscan(rel, DependDependerIndexId, true,
+							  NULL, 3, key);
+
+	while (HeapTupleIsValid(tup = systable_getnext(scan)))
+	{
+		Form_pg_depend depform = (Form_pg_depend) GETSTRUCT(tup);
+
+		if (list_member_oid(cmoids, depform->refobjid))
+		{
+			Assert(depform->refclassid == AccessMethodRelationId);
+			CatalogTupleDelete(rel, &tup->t_self);
+		}
+	}
+
+	systable_endscan(scan);
+	table_close(rel, lock);
+}
+
+/*
+ * Check whether the given compression method oid is supported by
+ * the target attribute.
+ */
+bool
+IsCompressionSupported(Form_pg_attribute att, Oid cmoid)
+{
+	List	   *cmoids = NIL;
+
+	/* Check whether it is same as the current compression oid */
+	if (cmoid == att->attcompression)
+		return true;
+
+	/* Check the oid in all preserved compresion methods */
+	cmoids = lookup_attribute_compression(att->attrelid, att->attnum, NULL);
+	if (list_member_oid(cmoids, cmoid))
+		return true;
+	else
+		return false;
+}
+
+/*
+ * In binary upgrade mode add the dependencies for all the preserved compression
+ * method.
+ */
+static void
+BinaryUpgradeAddPreserve(Form_pg_attribute att, List *preserve)
+{
+	ListCell   *cell;
+
+	foreach(cell, preserve)
+	{
+		char   *cmname_p = strVal(lfirst(cell));
+		Oid		cmoid_p = get_compression_am_oid(cmname_p, false);
+
+		add_column_compression_dependency(att->attrelid, att->attnum, cmoid_p);
+	}
+}
+
+/*
+ * Get the compression method oid based on the compression method name.  When
+ * compression is not specified returns default attribute compression.  It is
+ * possible case for CREATE TABLE and ADD COLUMN commands where COMPRESSION
+ * syntax is optional.
+ *
+ * For ALTER command, check all the supported compression methods for the
+ * attribute and if the preserve list is not passed or some of the old
+ * compression methods are not given in the preserved list then delete
+ * dependency from the old compression methods and force the table rewrite.
+ */
+Oid
+GetAttributeCompression(Form_pg_attribute att, ColumnCompression *compression,
+						bool *need_rewrite)
+{
+	Oid			cmoid;
+	char		typstorage = get_typstorage(att->atttypid);
+	ListCell   *cell;
+
+	/*
+	 * No compression for the plain/external storage, refer comments atop
+	 * attcompression parameter in pg_attribute.h
+	 */
+	if (!IsStorageCompressible(typstorage))
+	{
+		if (compression == NULL)
+			return InvalidOid;
+
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("column data type %s does not support compression",
+						format_type_be(att->atttypid))));
+	}
+
+	/* fallback to default compression if it's not specified */
+	if (compression == NULL)
+		return GetDefaultToastCompression();
+
+	cmoid = get_compression_am_oid(compression->cmname, false);
+
+#ifndef HAVE_LIBLZ4
+	if (cmoid == LZ4_COMPRESSION_AM_OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("not built with lz4 support")));
+#endif
+
+	/*
+	 * Determine if the column needs rewrite or not. Rewrite conditions: SET
+	 * COMPRESSION without PRESERVE - SET COMPRESSION with PRESERVE but not
+	 * with full list of previous access methods.
+	 */
+	if (need_rewrite != NULL)
+	{
+		List	   *previous_cmoids = NIL;
+
+		*need_rewrite = false;
+
+		/*
+		 * In binary upgrade mode, just create a dependency on all preserved
+		 * methods.
+		 */
+		if (IsBinaryUpgrade)
+		{
+			BinaryUpgradeAddPreserve(att, compression->preserve);
+			return cmoid;
+		}
+
+		/* If we have preserved all then rewrite is not required */
+		if (compression->preserve_all)
+			return cmoid;
+
+		previous_cmoids =
+			lookup_attribute_compression(att->attrelid, att->attnum, NULL);
+
+		foreach(cell, compression->preserve)
+		{
+			char   *cmname_p = strVal(lfirst(cell));
+			Oid		cmoid_p = get_compression_am_oid(cmname_p, false);
+
+			if (!list_member_oid(previous_cmoids, cmoid_p))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+							errmsg("\"%s\" compression access method cannot be preserved", cmname_p)));
+
+			/*
+			 * Remove from previous list, also protect from duplicate
+			 * entries in the PRESERVE list
+			 */
+			previous_cmoids = list_delete_oid(previous_cmoids, cmoid_p);
+		}
+
+		/* delete the current cmoid from the list */
+		previous_cmoids = list_delete_oid(previous_cmoids, cmoid);
+
+		/*
+		 * If the list of previous Oids is not empty after deletions then
+		 * we need to rewrite tuples in the table.  Also remove the dependency
+		 * on the old compression methods which are no longer preserved.
+		 */
+		if (list_length(previous_cmoids) != 0)
+		{
+			remove_old_dependencies(att->attrelid, att->attnum,
+									previous_cmoids);
+			*need_rewrite = true;
+		}
+
+		/* Cleanup */
+		list_free(previous_cmoids);
+	}
+
+	return cmoid;
+}
+
+/*
+ * Construct ColumnCompression node from the compression method oid.
+ */
+ColumnCompression *
+MakeColumnCompression(Oid attcompression)
+{
+	ColumnCompression *node;
+
+	if (!OidIsValid(attcompression))
+		return NULL;
+
+	node = makeNode(ColumnCompression);
+	node->cmname = get_am_name(attcompression);
+
+	return node;
+}
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 586a92f0c1..2a1841c353 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -530,7 +530,9 @@ static void ATExecEnableRowSecurity(Relation rel);
 static void ATExecDisableRowSecurity(Relation rel);
 static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls);
 static ObjectAddress ATExecSetCompression(AlteredTableInfo *tab, Relation rel,
-					 const char *column, Node *newValue, LOCKMODE lockmode);
+										  const char *column,
+										  ColumnCompression *compression,
+										  LOCKMODE lockmode);
 
 static void index_copy_data(Relation rel, RelFileNode newrnode);
 static const char *storage_name(char c);
@@ -562,7 +564,6 @@ static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx,
 static List *GetParentedForeignKeyRefs(Relation partition);
 static void ATDetachCheckNoForeignKeyRefs(Relation partition);
 static void ATExecAlterCollationRefreshVersion(Relation rel, List *coll);
-static Oid GetAttributeCompression(Form_pg_attribute att, char *compression);
 
 /* ----------------------------------------------------------------
  *		DefineRelation
@@ -587,6 +588,7 @@ ObjectAddress
 DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 			   ObjectAddress *typaddress, const char *queryString)
 {
+	int			i;
 	char		relname[NAMEDATALEN];
 	Oid			namespaceId;
 	Oid			relationId;
@@ -865,7 +867,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 			relkind == RELKIND_PARTITIONED_TABLE ||
 			relkind == RELKIND_MATVIEW)
 			attr->attcompression =
-				GetAttributeCompression(attr, colDef->compression);
+				GetAttributeCompression(attr, colDef->compression, NULL);
 		else
 			attr->attcompression = InvalidOid;
 	}
@@ -935,6 +937,20 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	 */
 	rel = relation_open(relationId, AccessExclusiveLock);
 
+	/*
+	 * Add the dependency on the respective compression AM for the relation
+	 * attributes.
+	 */
+	for (i = 0; i < (RelationGetDescr(rel))->natts; i++)
+	{
+		Form_pg_attribute attr;
+
+		attr = TupleDescAttr(RelationGetDescr(rel), i);
+		if (OidIsValid(attr->attcompression))
+			add_column_compression_dependency(attr->attrelid, attr->attnum,
+											  attr->attcompression);
+	}
+
 	/*
 	 * Now add any newly specified column default and generation expressions
 	 * to the new relation.  These are passed to us in the form of raw
@@ -2415,16 +2431,17 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
 				/* Copy/check compression parameter */
 				if (OidIsValid(attribute->attcompression))
 				{
-					char *compression = get_am_name(attribute->attcompression);
+					ColumnCompression *compression =
+							MakeColumnCompression(attribute->attcompression);
 
 					if (!def->compression)
 						def->compression = compression;
-					else if (strcmp(def->compression, compression) != 0)
+					else if (strcmp(def->compression->cmname, compression->cmname))
 						ereport(ERROR,
 								(errcode(ERRCODE_DATATYPE_MISMATCH),
 								 errmsg("column \"%s\" has a compression method conflict",
 										attributeName),
-								 errdetail("%s versus %s", def->compression, compression)));
+								 errdetail("%s versus %s", def->compression->cmname, compression->cmname)));
 				}
 
 				def->inhcount++;
@@ -2461,7 +2478,8 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
 				def->collOid = attribute->attcollation;
 				def->constraints = NIL;
 				def->location = -1;
-				def->compression = get_am_name(attribute->attcompression);
+				def->compression = MakeColumnCompression(
+											attribute->attcompression);
 				inhSchema = lappend(inhSchema, def);
 				newattmap->attnums[parent_attno - 1] = ++child_attno;
 			}
@@ -2712,12 +2730,12 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
 					def->compression = newdef->compression;
 				else if (newdef->compression)
 				{
-					if (strcmp(def->compression, newdef->compression))
+					if (strcmp(def->compression->cmname, newdef->compression->cmname))
 						ereport(ERROR,
 								(errcode(ERRCODE_DATATYPE_MISMATCH),
 								 errmsg("column \"%s\" has a compression method conflict",
 										attributeName),
-								 errdetail("%s versus %s", def->compression, newdef->compression)));
+								 errdetail("%s versus %s", def->compression->cmname, newdef->compression->cmname)));
 				}
 
 				/* Mark the column as locally defined */
@@ -4908,7 +4926,8 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			ATExecAlterCollationRefreshVersion(rel, cmd->object);
 			break;
 		case AT_SetCompression:
-			address = ATExecSetCompression(tab, rel, cmd->name, cmd->def,
+			address = ATExecSetCompression(tab, rel, cmd->name,
+										   (ColumnCompression *) cmd->def,
 										   lockmode);
 			break;
 		default:				/* oops */
@@ -6414,7 +6433,8 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	if (rel->rd_rel->relkind == RELKIND_RELATION ||
 		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
 		attribute.attcompression = GetAttributeCompression(&attribute,
-														   colDef->compression);
+														   colDef->compression,
+														   NULL);
 	else
 		attribute.attcompression = InvalidOid;
 
@@ -6589,6 +6609,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	 */
 	add_column_datatype_dependency(myrelid, newattnum, attribute.atttypid);
 	add_column_collation_dependency(myrelid, newattnum, attribute.attcollation);
+	add_column_compression_dependency(myrelid, newattnum, attribute.attcompression);
 
 	/*
 	 * Propagate to children as appropriate.  Unlike most other ALTER
@@ -6736,6 +6757,28 @@ add_column_collation_dependency(Oid relid, int32 attnum, Oid collid)
 	}
 }
 
+/*
+ * Install a dependency for compression on its column.
+ *
+ * This is used for identifying all the supported compression methods
+ * (current and preserved) for a attribute.
+ *
+ * If dependency is already there the whole thing is skipped.
+ */
+void
+add_column_compression_dependency(Oid relid, int32 attnum, Oid cmoid)
+{
+	ObjectAddress acref,
+		attref;
+
+	Assert(relid > 0 && attnum > 0);
+
+	ObjectAddressSet(acref, AccessMethodRelationId, cmoid);
+	ObjectAddressSubSet(attref, RelationRelationId, relid, attnum);
+
+	recordMultipleDependencies(&attref, &acref, 1, DEPENDENCY_NORMAL, true);
+}
+
 /*
  * ALTER TABLE ALTER COLUMN DROP NOT NULL
  */
@@ -11867,7 +11910,8 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 			  foundDep->refobjid == attTup->attcollation) &&
 			!(foundDep->refclassid == RelationRelationId &&
 			  foundDep->refobjid == RelationGetRelid(rel) &&
-			  foundDep->refobjsubid != 0)
+			  foundDep->refobjsubid != 0) &&
+			  foundDep->refclassid != AccessMethodRelationId
 			)
 			elog(ERROR, "found unexpected dependency for column: %s",
 				 getObjectDescription(&foundObject, false));
@@ -11982,6 +12026,11 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype);
 	add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid);
 
+	/* Create dependency for new attribute compression */
+	if (OidIsValid(attTup->attcompression))
+		add_column_compression_dependency(RelationGetRelid(rel), attnum,
+										  attTup->attcompression);
+
 	/*
 	 * Drop any pg_statistic entry for the column, since it's now wrong type
 	 */
@@ -15086,24 +15135,21 @@ static ObjectAddress
 ATExecSetCompression(AlteredTableInfo *tab,
 					 Relation rel,
 					 const char *column,
-					 Node *newValue,
+					 ColumnCompression *compression,
 					 LOCKMODE lockmode)
 {
 	Relation	attrel;
 	HeapTuple	tuple;
 	Form_pg_attribute atttableform;
 	AttrNumber	attnum;
-	char	   *compression;
 	char		typstorage;
 	Oid			cmoid;
+	bool		need_rewrite;
 	Datum		values[Natts_pg_attribute];
 	bool		nulls[Natts_pg_attribute];
 	bool		replace[Natts_pg_attribute];
 	ObjectAddress address;
 
-	Assert(IsA(newValue, String));
-	compression = strVal(newValue);
-
 	attrel = table_open(AttributeRelationId, RowExclusiveLock);
 
 	tuple = SearchSysCacheAttName(RelationGetRelid(rel), column);
@@ -15136,11 +15182,16 @@ ATExecSetCompression(AlteredTableInfo *tab,
 	memset(replace, false, sizeof(replace));
 
 	/* Get the attribute compression method. */
-	cmoid = GetAttributeCompression(atttableform, compression);
+	cmoid = GetAttributeCompression(atttableform, compression, &need_rewrite);
 
 	if (atttableform->attcompression != cmoid)
+		add_column_compression_dependency(atttableform->attrelid,
+										  atttableform->attnum, cmoid);
+	if (need_rewrite)
 		tab->rewrite |= AT_REWRITE_ALTER_COMPRESSION;
 
+	atttableform->attcompression = cmoid;
+
 	atttableform->attcompression = cmoid;
 	CatalogTupleUpdate(attrel, &tuple->t_self, tuple);
 
@@ -17865,42 +17916,3 @@ ATExecAlterCollationRefreshVersion(Relation rel, List *coll)
 	index_update_collation_versions(rel->rd_id, get_collation_oid(coll, false));
 	CacheInvalidateRelcache(rel);
 }
-
-/*
- * resolve column compression specification to an OID.
- */
-static Oid
-GetAttributeCompression(Form_pg_attribute att, char *compression)
-{
-	char		typstorage = get_typstorage(att->atttypid);
-	Oid			amoid;
-
-	/*
-	 * No compression for the plain/external storage, refer comments atop
-	 * attcompression parameter in pg_attribute.h
-	 */
-	if (!IsStorageCompressible(typstorage))
-	{
-		if (compression == NULL)
-			return InvalidOid;
-
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("column data type %s does not support compression",
-						format_type_be(att->atttypid))));
-	}
-
-	/* fallback to default compression if it's not specified */
-	if (compression == NULL)
-		return GetDefaultToastCompression();
-
-	amoid = get_compression_am_oid(compression, false);
-
-#ifndef HAVE_LIBLZ4
-	if (amoid == LZ4_COMPRESSION_AM_OID)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("not built with lz4 support")));
-#endif
-	return amoid;
-}
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index ea82a05591..90d092671e 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -44,6 +44,7 @@
 #include "access/tableam.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"
+#include "commands/defrem.h"
 #include "commands/trigger.h"
 #include "executor/execPartition.h"
 #include "executor/executor.h"
@@ -2068,8 +2069,8 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 
 	/*
 	 * Loop over all the attributes in the tuple and check if any attribute is
-	 * compressed and its compression method is not same as the target
-	 * atrribute's compression method then decompress it.
+	 * compressed and its compression method is not is not supported by the
+	 * target attribute then we need to decompress
 	 */
 	for (i = 0; i < natts; i++)
 	{
@@ -2094,12 +2095,13 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
 				DatumGetPointer(slot->tts_values[attnum - 1]);
 
 			/*
-			 * Get the compression method Oid stored in the toast header and
-			 * compare it with the compression method of the target.
+			 * Get the compression method stored in the toast header and if the
+			 * compression method is not supported by the target attribute then
+			 * we need to decompress it.
 			 */
 			cmoid = toast_get_compression_oid(new_value);
 			if (OidIsValid(cmoid) &&
-				targetTupDesc->attrs[i].attcompression != cmoid)
+				!IsCompressionSupported(&targetTupDesc->attrs[i], cmoid))
 			{
 				new_value = detoast_attr(new_value);
 				slot->tts_values[attnum - 1] = PointerGetDatum(new_value);
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 1338e04409..6a11f8eb60 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2966,7 +2966,7 @@ _copyColumnDef(const ColumnDef *from)
 
 	COPY_STRING_FIELD(colname);
 	COPY_NODE_FIELD(typeName);
-	COPY_STRING_FIELD(compression);
+	COPY_NODE_FIELD(compression);
 	COPY_SCALAR_FIELD(inhcount);
 	COPY_SCALAR_FIELD(is_local);
 	COPY_SCALAR_FIELD(is_not_null);
@@ -2986,6 +2986,18 @@ _copyColumnDef(const ColumnDef *from)
 	return newnode;
 }
 
+static ColumnCompression *
+_copyColumnCompression(const ColumnCompression *from)
+{
+	ColumnCompression *newnode = makeNode(ColumnCompression);
+
+	COPY_STRING_FIELD(cmname);
+	COPY_SCALAR_FIELD(preserve_all);
+	COPY_NODE_FIELD(preserve);
+
+	return newnode;
+}
+
 static Constraint *
 _copyConstraint(const Constraint *from)
 {
@@ -5675,6 +5687,9 @@ copyObjectImpl(const void *from)
 		case T_ColumnDef:
 			retval = _copyColumnDef(from);
 			break;
+		case T_ColumnCompression:
+			retval = _copyColumnCompression(from);
+			break;
 		case T_Constraint:
 			retval = _copyConstraint(from);
 			break;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index f3592003da..26a9b85974 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -2599,7 +2599,7 @@ _equalColumnDef(const ColumnDef *a, const ColumnDef *b)
 {
 	COMPARE_STRING_FIELD(colname);
 	COMPARE_NODE_FIELD(typeName);
-	COMPARE_STRING_FIELD(compression);
+	COMPARE_NODE_FIELD(compression);
 	COMPARE_SCALAR_FIELD(inhcount);
 	COMPARE_SCALAR_FIELD(is_local);
 	COMPARE_SCALAR_FIELD(is_not_null);
@@ -2619,6 +2619,16 @@ _equalColumnDef(const ColumnDef *a, const ColumnDef *b)
 	return true;
 }
 
+static bool
+_equalColumnCompression(const ColumnCompression *a, const ColumnCompression *b)
+{
+	COMPARE_STRING_FIELD(cmname);
+	COMPARE_SCALAR_FIELD(preserve_all);
+	COMPARE_NODE_FIELD(preserve);
+
+	return true;
+}
+
 static bool
 _equalConstraint(const Constraint *a, const Constraint *b)
 {
@@ -3724,6 +3734,9 @@ equal(const void *a, const void *b)
 		case T_ColumnDef:
 			retval = _equalColumnDef(a, b);
 			break;
+		case T_ColumnCompression:
+			retval = _equalColumnCompression(a, b);
+			break;
 		case T_Constraint:
 			retval = _equalConstraint(a, b);
 			break;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 0605ef3f84..b584a58ba3 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2863,7 +2863,7 @@ _outColumnDef(StringInfo str, const ColumnDef *node)
 
 	WRITE_STRING_FIELD(colname);
 	WRITE_NODE_FIELD(typeName);
-	WRITE_STRING_FIELD(compression);
+	WRITE_NODE_FIELD(compression);
 	WRITE_INT_FIELD(inhcount);
 	WRITE_BOOL_FIELD(is_local);
 	WRITE_BOOL_FIELD(is_not_null);
@@ -2881,6 +2881,16 @@ _outColumnDef(StringInfo str, const ColumnDef *node)
 	WRITE_LOCATION_FIELD(location);
 }
 
+static void
+_outColumnCompression(StringInfo str, const ColumnCompression *node)
+{
+	WRITE_NODE_TYPE("COLUMNCOMPRESSION");
+
+	WRITE_STRING_FIELD(cmname);
+	WRITE_BOOL_FIELD(preserve_all);
+	WRITE_NODE_FIELD(preserve);
+}
+
 static void
 _outTypeName(StringInfo str, const TypeName *node)
 {
@@ -4258,6 +4268,9 @@ outNode(StringInfo str, const void *obj)
 			case T_ColumnDef:
 				_outColumnDef(str, obj);
 				break;
+			case T_ColumnCompression:
+				_outColumnCompression(str, obj);
+				break;
 			case T_TypeName:
 				_outTypeName(str, obj);
 				break;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 30acfe615d..9eb2b04d58 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -596,7 +596,9 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <list>		hash_partbound
 %type <defelt>		hash_partbound_elem
 
-%type <str>	optColumnCompression
+%type <node>	optColumnCompression alterColumnCompression
+%type <str>		compressionClause
+%type <list>	optCompressionPreserve
 
 /*
  * Non-keyword token types.  These are hard-wired into the "flex" lexer.
@@ -2309,12 +2311,12 @@ alter_table_cmd:
 					$$ = (Node *)n;
 				}
 			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET (COMPRESSION <cm>) */
-			| ALTER opt_column ColId SET optColumnCompression
+			| ALTER opt_column ColId SET alterColumnCompression
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
 					n->subtype = AT_SetCompression;
 					n->name = $3;
-					n->def = (Node *) makeString($5);
+					n->def = $5;
 					$$ = (Node *)n;
 				}
 			/* ALTER TABLE <name> DROP [COLUMN] IF EXISTS <colname> [RESTRICT|CASCADE] */
@@ -3437,7 +3439,7 @@ columnDef:	ColId Typename optColumnCompression create_generic_options ColQualLis
 					ColumnDef *n = makeNode(ColumnDef);
 					n->colname = $1;
 					n->typeName = $2;
-					n->compression = $3;
+					n->compression = (ColumnCompression *) $3;
 					n->inhcount = 0;
 					n->is_local = true;
 					n->is_not_null = false;
@@ -3492,13 +3494,43 @@ columnOptions:	ColId ColQualList
 				}
 		;
 
+optCompressionPreserve:
+			PRESERVE '(' name_list ')' { $$ = $3; }
+			| /*EMPTY*/ { $$ = NULL; }
+		;
+
+compressionClause:
+			COMPRESSION name { $$ = pstrdup($2); }
+		;
+
 optColumnCompression:
-					COMPRESSION name
-					{
-						$$ = $2;
-					}
-					| /*EMPTY*/	{ $$ = NULL; }
-				;
+			compressionClause
+				{
+					ColumnCompression *n = makeNode(ColumnCompression);
+					n->cmname = $1;
+					n->preserve = NIL;
+					$$ = (Node *) n;
+				}
+			| /*EMPTY*/	{ $$ = NULL; }
+		;
+
+alterColumnCompression:
+			compressionClause optCompressionPreserve
+				{
+					ColumnCompression *n = makeNode(ColumnCompression);
+					n->cmname = $1;
+					n->preserve = (List *) $2;
+					$$ = (Node *) n;
+				}
+			|	compressionClause PRESERVE ALL
+				{
+					ColumnCompression *n = makeNode(ColumnCompression);
+					n->cmname = $1;
+					n->preserve_all = true;
+					n->preserve = NIL;
+					$$ = (Node *) n;
+				}
+		;
 
 ColQualList:
 			ColQualList ColConstraint				{ $$ = lappend($1, $2); }
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index cf4413da64..45f4724a13 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -1086,7 +1086,7 @@ transformTableLikeClause(CreateStmtContext *cxt, TableLikeClause *table_like_cla
 		/* Likewise, copy compression if requested */
 		if ((table_like_clause->options & CREATE_TABLE_LIKE_COMPRESSION) != 0
 			&& OidIsValid(attribute->attcompression))
-			def->compression = get_am_name(attribute->attcompression);
+			def->compression = MakeColumnCompression(attribute->attcompression);
 		else
 			def->compression = NULL;
 
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 46044cb92a..7bf345a4ac 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -9037,6 +9037,80 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 			}
 			PQclear(res);
 		}
+
+		/*
+		 * Get compression info
+		 */
+		if (fout->remoteVersion >= 140000 && dopt->binary_upgrade)
+		{
+			int			i_amname;
+			int			i_amoid;
+			int			i_curattnum;
+			int			start;
+
+			pg_log_info("finding compression info for table \"%s.%s\"",
+						tbinfo->dobj.namespace->dobj.name,
+						tbinfo->dobj.name);
+
+			tbinfo->attcompression = pg_malloc0(tbinfo->numatts * sizeof(AttrCompressionInfo *));
+
+			resetPQExpBuffer(q);
+			appendPQExpBuffer(q,
+				" SELECT attrelid::pg_catalog.regclass AS relname, attname,"
+				" amname, am.oid as amoid, d.objsubid AS curattnum"
+				" FROM pg_depend d"
+				" JOIN pg_attribute a ON"
+				"	(classid = 'pg_class'::pg_catalog.regclass::pg_catalog.oid AND a.attrelid = d.objid"
+				"		AND a.attnum = d.objsubid AND d.deptype = 'n'"
+				"		AND d.refclassid = 'pg_am'::pg_catalog.regclass::pg_catalog.oid)"
+				" JOIN pg_am am ON"
+				"	(d.deptype = 'n' AND d.refobjid = am.oid)"
+				" WHERE (deptype = 'n' AND d.objid = %d AND a.attcompression != am.oid);",
+				tbinfo->dobj.catId.oid);
+
+			res = ExecuteSqlQuery(fout, q->data, PGRES_TUPLES_OK);
+			ntups = PQntuples(res);
+
+			if (ntups > 0)
+			{
+				int		j;
+				int		k;
+
+				i_amname = PQfnumber(res, "amname");
+				i_amoid = PQfnumber(res, "amoid");
+				i_curattnum = PQfnumber(res, "curattnum");
+
+				start = 0;
+
+				for (j = 0; j < ntups; j++)
+				{
+					int		attnum = atoi(PQgetvalue(res, j, i_curattnum));
+
+					if ((j == ntups - 1) || atoi(PQgetvalue(res, j + 1, i_curattnum)) != attnum)
+					{
+						AttrCompressionInfo *cminfo = pg_malloc(sizeof(AttrCompressionInfo));
+
+						cminfo->nitems = j - start + 1;
+						cminfo->items = pg_malloc(sizeof(AttrCompressionItem *) * cminfo->nitems);
+
+						for (k = start; k < start + cminfo->nitems; k++)
+						{
+							AttrCompressionItem	*cmitem = pg_malloc0(sizeof(AttrCompressionItem));
+
+							cmitem->amname = pg_strdup(PQgetvalue(res, k, i_amname));
+							cmitem->amoid = atooid(PQgetvalue(res, k, i_amoid));
+
+							cminfo->items[k - start] = cmitem;
+						}
+
+						tbinfo->attcompression[attnum - 1] = cminfo;
+						start = j + 1;	/* start from next */
+					}
+				}
+			}
+
+			PQclear(res);
+		}
 	}
 
 	destroyPQExpBuffer(q);
@@ -16343,6 +16417,33 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo)
 								  qualrelname,
 								  fmtId(tbinfo->attnames[j]),
 								  tbinfo->attfdwoptions[j]);
+
+			/*
+			 * Dump per-column compression options
+			 */
+			if (tbinfo->attcompression && tbinfo->attcompression[j])
+			{
+				AttrCompressionInfo *cminfo = tbinfo->attcompression[j];
+
+				appendPQExpBuffer(q, "ALTER TABLE %s ALTER COLUMN %s\nSET COMPRESSION %s",
+									qualrelname, fmtId(tbinfo->attnames[j]), tbinfo->attcmnames[j]);
+
+				if (cminfo->nitems > 0)
+				{
+					appendPQExpBuffer(q, "\nPRESERVE (");
+					for (int i = 0; i < cminfo->nitems; i++)
+					{
+						AttrCompressionItem *item = cminfo->items[i];
+
+						if (i == 0)
+							appendPQExpBuffer(q, "%s", item->amname);
+						else
+							appendPQExpBuffer(q, ", %s", item->amname);
+					}
+					appendPQExpBuffer(q, ")");
+				}
+				appendPQExpBuffer(q, ";\n");
+			}
 		}
 
 		if (ftoptions)
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 1789e18f46..a829528cd0 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -327,7 +327,8 @@ typedef struct _tableInfo
 	bool		needs_override; /* has GENERATED ALWAYS AS IDENTITY */
 	char	   *amname;			/* relation access method */
 	char	  **attcmnames;		/* per-attribute current compression method */
-
+	struct _attrCompressionInfo **attcompression; /* per-attribute all
+													 compression data */
 	/*
 	 * Stuff computed only for dumpable tables.
 	 */
@@ -356,6 +357,18 @@ typedef struct _attrDefInfo
 	bool		separate;		/* true if must dump as separate item */
 } AttrDefInfo;
 
+typedef struct _attrCompressionItem
+{
+	Oid			amoid;			/* attribute compression oid */
+	char	   *amname;			/* compression access method name */
+} AttrCompressionItem;
+
+typedef struct _attrCompressionInfo
+{
+	int			nitems;
+	AttrCompressionItem	**items;
+} AttrCompressionInfo;
+
 typedef struct _tableDataInfo
 {
 	DumpableObject dobj;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index ffa8d05edf..869fd3676d 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2103,6 +2103,13 @@ psql_completion(const char *text, int start, int end)
 	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET", "(") ||
 			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET", "("))
 		COMPLETE_WITH("n_distinct", "n_distinct_inherited");
+	/* ALTER TABLE ALTER [COLUMN] <foo> SET COMPRESSION */
+	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET", "COMPRESSION", MatchAny) ||
+			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET", "COMPRESSION", MatchAny))
+		COMPLETE_WITH("PRESERVE");
+	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET", "COMPRESSION", MatchAny, "PRESERVE") ||
+			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET", "COMPRESSION", MatchAny, "PRESERVE"))
+		COMPLETE_WITH("( ", "ALL");
 	/* ALTER TABLE ALTER [COLUMN] <foo> SET STORAGE */
 	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER", "COLUMN", MatchAny, "SET", "STORAGE") ||
 			 Matches("ALTER", "TABLE", MatchAny, "ALTER", MatchAny, "SET", "STORAGE"))
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index e5aea8a240..bd53f9bb0f 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -143,6 +143,13 @@ extern Oid	get_compression_am_oid(const char *amname, bool missing_ok);
 extern Oid	get_am_oid(const char *amname, bool missing_ok);
 extern char *get_am_name(Oid amOid);
 
+/* commands/compressioncmds.c */
+extern Oid GetAttributeCompression(Form_pg_attribute att,
+								   ColumnCompression *compression,
+								   bool *need_rewrite);
+extern ColumnCompression *MakeColumnCompression(Oid atttcompression);
+extern bool IsCompressionSupported(Form_pg_attribute att, Oid cmoid);
+
 /* support routines in commands/define.c */
 
 extern char *defGetString(DefElem *def);
diff --git a/src/include/commands/tablecmds.h b/src/include/commands/tablecmds.h
index b3d30acc35..e6c98e65d4 100644
--- a/src/include/commands/tablecmds.h
+++ b/src/include/commands/tablecmds.h
@@ -97,5 +97,7 @@ extern void RangeVarCallbackOwnsRelation(const RangeVar *relation,
 										 Oid relId, Oid oldRelId, void *arg);
 extern bool PartConstraintImpliedByRelConstraint(Relation scanrel,
 												 List *partConstraint);
+extern void add_column_compression_dependency(Oid relid, int32 attnum,
+											  Oid cmoid);
 
 #endif							/* TABLECMDS_H */
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 20d6f96f62..24deaad253 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -481,6 +481,7 @@ typedef enum NodeTag
 	T_PartitionBoundSpec,
 	T_PartitionRangeDatum,
 	T_PartitionCmd,
+	T_ColumnCompression,
 	T_VacuumRelation,
 
 	/*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index f9a87dee02..ce0913e18a 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -623,6 +623,20 @@ typedef struct RangeTableSample
 	int			location;		/* method name location, or -1 if unknown */
 } RangeTableSample;
 
+/*
+ * ColumnCompression - compression parameters for some attribute
+ *
+ * This represents compression information defined using clause:
+ * .. COMPRESSION <compression method> PRESERVE <compression methods>
+ */
+typedef struct ColumnCompression
+{
+	NodeTag		type;
+	char	   *cmname;
+	bool		preserve_all;
+	List	   *preserve;
+} ColumnCompression;
+
 /*
  * ColumnDef - column definition (used in various creates)
  *
@@ -646,7 +660,7 @@ typedef struct ColumnDef
 	NodeTag		type;
 	char	   *colname;		/* name of column */
 	TypeName   *typeName;		/* type of column */
-	char	   *compression;	/* compression method for column */
+	ColumnCompression *compression;	/* column compression */
 	int			inhcount;		/* number of times column is inherited */
 	bool		is_local;		/* column has local (non-inherited) def'n */
 	bool		is_not_null;	/* NOT NULL constraint specified? */
diff --git a/src/test/regress/expected/compression.out b/src/test/regress/expected/compression.out
index 21c1b451d2..3ed33b6534 100644
--- a/src/test/regress/expected/compression.out
+++ b/src/test/regress/expected/compression.out
@@ -226,12 +226,47 @@ SELECT pg_column_compression(f1) FROM cmpart;
  lz4
 (2 rows)
 
+-- preserve old compression method
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION pglz PRESERVE (lz4);
+INSERT INTO cmdata VALUES (repeat('1234567890',1004));
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
+Indexes:
+    "idx" btree (f1)
+
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ lz4
+ pglz
+(2 rows)
+
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
+Indexes:
+    "idx" btree (f1)
+
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4 PRESERVE ALL;
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ lz4
+ pglz
+(2 rows)
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
 --------
   10000
-(1 row)
+  10040
+(2 rows)
 
 SELECT length(f1) FROM cmdata1;
  length 
diff --git a/src/test/regress/expected/compression_1.out b/src/test/regress/expected/compression_1.out
index 64c5855bf7..36a5f8ba5e 100644
--- a/src/test/regress/expected/compression_1.out
+++ b/src/test/regress/expected/compression_1.out
@@ -205,12 +205,49 @@ SELECT pg_column_compression(f1) FROM cmpart;
 ERROR:  relation "cmpart" does not exist
 LINE 1: SELECT pg_column_compression(f1) FROM cmpart;
                                               ^
+-- preserve old compression method
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION pglz PRESERVE (lz4);
+ERROR:  "lz4" compression access method cannot be preserved
+INSERT INTO cmdata VALUES (repeat('1234567890',1004));
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
+Indexes:
+    "idx" btree (f1)
+
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ pglz
+ pglz
+(2 rows)
+
+\d+ cmdata
+                                        Table "public.cmdata"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | pglz        |              | 
+Indexes:
+    "idx" btree (f1)
+
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4 PRESERVE ALL;
+ERROR:  not built with lz4 support
+SELECT pg_column_compression(f1) FROM cmdata;
+ pg_column_compression 
+-----------------------
+ pglz
+ pglz
+(2 rows)
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
 --------
   10000
-(1 row)
+  10040
+(2 rows)
 
 SELECT length(f1) FROM cmdata1;
 ERROR:  relation "cmdata1" does not exist
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index 830fdddf24..8f984510ac 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -2066,19 +2066,21 @@ WHERE classid = 'pg_class'::regclass AND
 	    'concur_reindex_ind4'::regclass,
 	    'concur_reindex_matview'::regclass)
   ORDER BY 1, 2;
-                   obj                    |                           objref                           | deptype 
-------------------------------------------+------------------------------------------------------------+---------
- index concur_reindex_ind1                | constraint concur_reindex_ind1 on table concur_reindex_tab | i
- index concur_reindex_ind2                | collation "default"                                        | n
- index concur_reindex_ind2                | column c2 of table concur_reindex_tab                      | a
- index concur_reindex_ind3                | column c1 of table concur_reindex_tab                      | a
- index concur_reindex_ind3                | table concur_reindex_tab                                   | a
- index concur_reindex_ind4                | collation "default"                                        | n
- index concur_reindex_ind4                | column c1 of table concur_reindex_tab                      | a
- index concur_reindex_ind4                | column c2 of table concur_reindex_tab                      | a
- materialized view concur_reindex_matview | schema public                                              | n
- table concur_reindex_tab                 | schema public                                              | n
-(10 rows)
+                          obj                          |                           objref                           | deptype 
+-------------------------------------------------------+------------------------------------------------------------+---------
+ column c2 of materialized view concur_reindex_matview | access method pglz                                         | n
+ column c2 of table concur_reindex_tab                 | access method pglz                                         | n
+ index concur_reindex_ind1                             | constraint concur_reindex_ind1 on table concur_reindex_tab | i
+ index concur_reindex_ind2                             | collation "default"                                        | n
+ index concur_reindex_ind2                             | column c2 of table concur_reindex_tab                      | a
+ index concur_reindex_ind3                             | column c1 of table concur_reindex_tab                      | a
+ index concur_reindex_ind3                             | table concur_reindex_tab                                   | a
+ index concur_reindex_ind4                             | collation "default"                                        | n
+ index concur_reindex_ind4                             | column c1 of table concur_reindex_tab                      | a
+ index concur_reindex_ind4                             | column c2 of table concur_reindex_tab                      | a
+ materialized view concur_reindex_matview              | schema public                                              | n
+ table concur_reindex_tab                              | schema public                                              | n
+(12 rows)
 
 REINDEX INDEX CONCURRENTLY concur_reindex_ind1;
 REINDEX TABLE CONCURRENTLY concur_reindex_tab;
@@ -2095,19 +2097,21 @@ WHERE classid = 'pg_class'::regclass AND
 	    'concur_reindex_ind4'::regclass,
 	    'concur_reindex_matview'::regclass)
   ORDER BY 1, 2;
-                   obj                    |                           objref                           | deptype 
-------------------------------------------+------------------------------------------------------------+---------
- index concur_reindex_ind1                | constraint concur_reindex_ind1 on table concur_reindex_tab | i
- index concur_reindex_ind2                | collation "default"                                        | n
- index concur_reindex_ind2                | column c2 of table concur_reindex_tab                      | a
- index concur_reindex_ind3                | column c1 of table concur_reindex_tab                      | a
- index concur_reindex_ind3                | table concur_reindex_tab                                   | a
- index concur_reindex_ind4                | collation "default"                                        | n
- index concur_reindex_ind4                | column c1 of table concur_reindex_tab                      | a
- index concur_reindex_ind4                | column c2 of table concur_reindex_tab                      | a
- materialized view concur_reindex_matview | schema public                                              | n
- table concur_reindex_tab                 | schema public                                              | n
-(10 rows)
+                          obj                          |                           objref                           | deptype 
+-------------------------------------------------------+------------------------------------------------------------+---------
+ column c2 of materialized view concur_reindex_matview | access method pglz                                         | n
+ column c2 of table concur_reindex_tab                 | access method pglz                                         | n
+ index concur_reindex_ind1                             | constraint concur_reindex_ind1 on table concur_reindex_tab | i
+ index concur_reindex_ind2                             | collation "default"                                        | n
+ index concur_reindex_ind2                             | column c2 of table concur_reindex_tab                      | a
+ index concur_reindex_ind3                             | column c1 of table concur_reindex_tab                      | a
+ index concur_reindex_ind3                             | table concur_reindex_tab                                   | a
+ index concur_reindex_ind4                             | collation "default"                                        | n
+ index concur_reindex_ind4                             | column c1 of table concur_reindex_tab                      | a
+ index concur_reindex_ind4                             | column c2 of table concur_reindex_tab                      | a
+ materialized view concur_reindex_matview              | schema public                                              | n
+ table concur_reindex_tab                              | schema public                                              | n
+(12 rows)
 
 -- Check that comments are preserved
 CREATE TABLE testcomment (i int);
diff --git a/src/test/regress/sql/compression.sql b/src/test/regress/sql/compression.sql
index b9daa33b74..5774b55d82 100644
--- a/src/test/regress/sql/compression.sql
+++ b/src/test/regress/sql/compression.sql
@@ -96,6 +96,15 @@ ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
 ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
 SELECT pg_column_compression(f1) FROM cmpart;
 
+-- preserve old compression method
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION pglz PRESERVE (lz4);
+INSERT INTO cmdata VALUES (repeat('1234567890',1004));
+\d+ cmdata
+SELECT pg_column_compression(f1) FROM cmdata;
+\d+ cmdata
+ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4 PRESERVE ALL;
+SELECT pg_column_compression(f1) FROM cmdata;
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
 SELECT length(f1) FROM cmdata1;
-- 
2.17.0

view thread (430+ messages)  latest in thread

Message-ID: <20210214184940.GL1793@telsasoft.com>
Permalink:  ../20210214184940.GL1793@telsasoft.com/
Also on:    postgresql.org/message-id/20210214184940.GL1793@telsasoft.com

 ·  · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-hackers@postgresql.org
  Cc: pryzby@telsasoft.com, robertmhaas@gmail.com, dilipbalaut@gmail.com, tomas.vondra@2ndquadrant.com, a.korotkov@postgrespro.ru, david@pgmasters.net, i.kurbangaliev@gmail.com, 9erthalion6@gmail.com, pgsql-hackers@lists.postgresql.org
  Subject: Re: [HACKERS] Custom compression methods
  In-Reply-To: <20210214184940.GL1793@telsasoft.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox