Split regression tests for TOAST compression methods into two files

The regression tests for TOAST compression methods are split into two
independent files: one specific to LZ4 and interactions between two
different TOAST compression methods, now called compression_lz4, and a
second one for the "core" cases where only pglz is required.

This saves 300 lines in diffs coming from the alternate output of
compression.sql, required for builds where lz4 is not available.  The
new test is skipped if the build does not support LZ4 compression,
relying on an \if and the values reported in pg_settings for the GUC
default_toast_compression, "lz4" being available only under USE_LZ4.

Another benefit of this split is that this facilitates the addition of
more compression methods for TOAST, which are under discussion.

Note the trick added for the tests of the GUC default_toast_compression,
where VERBOSITY = terse is used to avoid the HINT printing the lists of
values available in the GUC, which are environment-dependent.  This
makes compression.sql independent of the availability of LZ4.

The code coverage of toast_compression.c is slightly improved, increased
from 89% to 91%, with one new case covered in lz4_compress_datum() for
incompressible data.

Author: Nikhil Kumar Veldanda <veldanda.nikhilkumar17@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aDlcU-ym9KfMj9sG@paquier.xyz

src/test/regress/expected/compression.out

@@ -1,3 +1,7 @@
+-- Default set of tests for TOAST compression, independent on compression
+-- methods supported by the build.
+CREATE SCHEMA pglz;
+SET search_path TO pglz, public;
 \set HIDE_TOAST_COMPRESSION false
 -- ensure we get stable results regardless of installation's default
 SET default_toast_compression = 'pglz';
@@ -6,21 +10,13 @@ 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"
+                                         Table "pglz.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  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | text |           |          |         | extended | lz4         |              | 
-
 -- verify stored compression method in the data
 SELECT pg_column_compression(f1) FROM cmdata;
  pg_column_compression 
@@ -28,12 +24,6 @@ SELECT pg_column_compression(f1) FROM cmdata;
  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 
@@ -41,16 +31,10 @@ SELECT SUBSTR(f1, 200, 5) FROM cmdata;
  01234
 (1 row)
 
-SELECT SUBSTR(f1, 2000, 50) FROM cmdata1;
-                       substr                       
-----------------------------------------------------
- 01234567890123456789012345678901234567890123456789
-(1 row)
-
 -- copy with table creation
 SELECT * INTO cmmove1 FROM cmdata;
 \d+ cmmove1
-                                        Table "public.cmmove1"
+                                         Table "pglz.cmmove1"
  Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
 --------+------+-----------+----------+---------+----------+-------------+--------------+-------------
  f1     | text |           |          |         | extended |             |              | 
@@ -61,45 +45,9 @@ SELECT pg_column_compression(f1) FROM cmmove1;
  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 cmmove3;
- pg_column_compression 
------------------------
- pglz
- lz4
-(2 rows)
-
--- test LIKE INCLUDING COMPRESSION
-CREATE TABLE cmdata2 (LIKE cmdata1 INCLUDING COMPRESSION);
-\d+ cmdata2
-                                        Table "public.cmdata2"
- Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | text |           |          |         | extended | lz4         |              | 
-
-DROP TABLE cmdata2;
 -- try setting compression for incompressible data type
 CREATE TABLE cmdata2 (f1 int COMPRESSION pglz);
 ERROR:  column data type integer does not support compression
--- 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 = cmdata1.f1 FROM cmdata1;
-SELECT pg_column_compression(f1) FROM cmmove2;
- pg_column_compression 
------------------------
- lz4
-(1 row)
-
 -- test externally stored compressed data
 CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS
 'select array_agg(fipshash(g::text))::text from generate_series(1, 256) g';
@@ -111,21 +59,6 @@ SELECT pg_column_compression(f1) FROM cmdata2;
  pglz
 (1 row)
 
-INSERT INTO cmdata1 SELECT large_val() || repeat('a', 4000);
-SELECT pg_column_compression(f1) FROM cmdata1;
- pg_column_compression 
------------------------
- lz4
- lz4
-(2 rows)
-
-SELECT SUBSTR(f1, 200, 5) FROM cmdata1;
- substr 
---------
- 01234
- 79026
-(2 rows)
-
 SELECT SUBSTR(f1, 200, 5) FROM cmdata2;
  substr 
 --------
@@ -136,21 +69,21 @@ DROP TABLE cmdata2;
 --test column type update varlena/non-varlena
 CREATE TABLE cmdata2 (f1 int);
 \d+ cmdata2
-                                         Table "public.cmdata2"
+                                          Table "pglz.cmdata2"
  Column |  Type   | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
 --------+---------+-----------+----------+---------+---------+-------------+--------------+-------------
  f1     | integer |           |          |         | plain   |             |              | 
 
 ALTER TABLE cmdata2 ALTER COLUMN f1 TYPE varchar;
 \d+ cmdata2
-                                              Table "public.cmdata2"
+                                               Table "pglz.cmdata2"
  Column |       Type        | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
 --------+-------------------+-----------+----------+---------+----------+-------------+--------------+-------------
  f1     | character varying |           |          |         | extended |             |              | 
 
 ALTER TABLE cmdata2 ALTER COLUMN f1 TYPE int USING f1::integer;
 \d+ cmdata2
-                                         Table "public.cmdata2"
+                                          Table "pglz.cmdata2"
  Column |  Type   | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
 --------+---------+-----------+----------+---------+---------+-------------+--------------+-------------
  f1     | integer |           |          |         | plain   |             |              | 
@@ -160,14 +93,14 @@ ALTER TABLE cmdata2 ALTER COLUMN f1 TYPE int USING f1::integer;
 ALTER TABLE cmdata2 ALTER COLUMN f1 TYPE varchar;
 ALTER TABLE cmdata2 ALTER COLUMN f1 SET COMPRESSION pglz;
 \d+ cmdata2
-                                              Table "public.cmdata2"
+                                               Table "pglz.cmdata2"
  Column |       Type        | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
 --------+-------------------+-----------+----------+---------+----------+-------------+--------------+-------------
  f1     | character varying |           |          |         | extended | pglz        |              | 
 
 ALTER TABLE cmdata2 ALTER COLUMN f1 SET STORAGE plain;
 \d+ cmdata2
-                                              Table "public.cmdata2"
+                                               Table "pglz.cmdata2"
  Column |       Type        | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
 --------+-------------------+-----------+----------+---------+---------+-------------+--------------+-------------
  f1     | character varying |           |          |         | plain   | pglz        |              | 
@@ -179,164 +112,47 @@ SELECT pg_column_compression(f1) FROM cmdata2;
  
 (1 row)
 
--- test compression with materialized view
-CREATE MATERIALIZED VIEW compressmv(x) AS SELECT * FROM cmdata1;
-\d+ compressmv
-                                Materialized view "public.compressmv"
- Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- x      | text |           |          |         | extended |             |              | 
-View definition:
- SELECT 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 compressmv;
- pg_column_compression 
------------------------
- lz4
- lz4
-(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 cmpart1;
- pg_column_compression 
------------------------
- lz4
-(1 row)
-
-SELECT pg_column_compression(f1) FROM cmpart2;
- pg_column_compression 
------------------------
- pglz
-(1 row)
-
 -- test compression with inheritance
-CREATE TABLE cminh() INHERITS(cmdata, cmdata1); -- error
-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); -- error
-NOTICE:  merging column "f1" with inherited definition
-ERROR:  column "f1" has a compression method conflict
-DETAIL:  pglz versus lz4
 CREATE TABLE cmdata3(f1 text);
 CREATE TABLE cminh() INHERITS (cmdata, cmdata3);
 NOTICE:  merging multiple inherited definitions of column "f1"
 -- test default_toast_compression GUC
+-- suppress machine-dependent details
+\set VERBOSITY terse
 SET default_toast_compression = '';
 ERROR:  invalid value for parameter "default_toast_compression": ""
-HINT:  Available values: pglz, lz4.
 SET default_toast_compression = 'I do not exist compression';
 ERROR:  invalid value for parameter "default_toast_compression": "I do not exist compression"
-HINT:  Available values: pglz, lz4.
-SET default_toast_compression = 'lz4';
 SET default_toast_compression = 'pglz';
--- test alter compression method
-ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
-INSERT INTO cmdata VALUES (repeat('123456789', 4004));
-\d+ cmdata
-                                        Table "public.cmdata"
- Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | text |           |          |         | extended | lz4         |              | 
-Indexes:
-    "idx" btree (f1)
-Child tables: cminh
-
-SELECT pg_column_compression(f1) FROM cmdata;
- pg_column_compression 
------------------------
- pglz
- lz4
-(2 rows)
-
+\set VERBOSITY default
 ALTER TABLE cmdata2 ALTER COLUMN f1 SET COMPRESSION default;
 \d+ cmdata2
-                                              Table "public.cmdata2"
+                                               Table "pglz.cmdata2"
  Column |       Type        | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
 --------+-------------------+-----------+----------+---------+---------+-------------+--------------+-------------
  f1     | character varying |           |          |         | plain   |             |              | 
 
--- test alter compression method for materialized views
-ALTER MATERIALIZED VIEW compressmv ALTER COLUMN x SET COMPRESSION lz4;
-\d+ compressmv
-                                Materialized view "public.compressmv"
- Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- x      | text |           |          |         | extended | lz4         |              | 
-View definition:
- SELECT f1 AS x
-   FROM cmdata1;
-
--- test alter compression method for partitioned tables
-ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
-ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
--- new data should be compressed with the current compression method
-INSERT INTO cmpart VALUES (repeat('123456789', 1004));
-INSERT INTO cmpart VALUES (repeat('123456789', 4004));
-SELECT pg_column_compression(f1) FROM cmpart1;
- pg_column_compression 
------------------------
- lz4
- pglz
-(2 rows)
-
-SELECT pg_column_compression(f1) FROM cmpart2;
- pg_column_compression 
------------------------
- pglz
- lz4
-(2 rows)
-
+DROP TABLE cmdata2;
 -- VACUUM FULL does not recompress
 SELECT pg_column_compression(f1) FROM cmdata;
  pg_column_compression 
 -----------------------
  pglz
- lz4
-(2 rows)
+(1 row)
 
 VACUUM FULL cmdata;
 SELECT pg_column_compression(f1) FROM cmdata;
  pg_column_compression 
 -----------------------
  pglz
- lz4
-(2 rows)
+(1 row)
 
--- test expression index
-DROP TABLE cmdata2;
-CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
-CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
-INSERT INTO cmdata2 VALUES((SELECT array_agg(fipshash(g::TEXT))::TEXT FROM
-generate_series(1, 50) g), VERSION());
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
 --------
   10000
-  36036
-(2 rows)
-
-SELECT length(f1) FROM cmdata1;
- length 
---------
-  10040
-  12449
-(2 rows)
+(1 row)
 
 SELECT length(f1) FROM cmmove1;
  length 
@@ -344,19 +160,6 @@ SELECT length(f1) FROM cmmove1;
   10000
 (1 row)
 
-SELECT length(f1) FROM cmmove2;
- length 
---------
-  10040
-(1 row)
-
-SELECT length(f1) FROM cmmove3;
- length 
---------
-  10000
-  10040
-(2 rows)
-
 CREATE TABLE badcompresstbl (a text COMPRESSION I_Do_Not_Exist_Compression); -- fails
 ERROR:  invalid compression method "i_do_not_exist_compression"
 CREATE TABLE badcompresstbl (a text);

src/test/regress/expected/compression_1.out

@@ -1,360 +0,0 @@
-\set HIDE_TOAST_COMPRESSION false
--- ensure we get stable results regardless of installation's default
-SET default_toast_compression = 'pglz';
--- 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  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | text |           |          |         | extended | pglz        |              | 
-Indexes:
-    "idx" btree (f1)
-
-CREATE TABLE cmdata1(f1 TEXT COMPRESSION lz4);
-ERROR:  compression method lz4 not supported
-DETAIL:  This functionality requires the server to be 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
--- verify stored compression method in the data
-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;
-\d+ cmmove1
-                                        Table "public.cmmove1"
- Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | text |           |          |         | extended |             |              | 
-
-SELECT pg_column_compression(f1) FROM cmmove1;
- 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 cmmove3;
- pg_column_compression 
------------------------
- pglz
-(1 row)
-
--- 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
-DROP TABLE cmdata2;
-ERROR:  table "cmdata2" does not exist
--- try setting compression for incompressible data type
-CREATE TABLE cmdata2 (f1 int COMPRESSION pglz);
-ERROR:  column data type integer does not support compression
--- 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 = 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)
-
--- test externally stored compressed data
-CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS
-'select array_agg(fipshash(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 large_val() || repeat('a', 4000);
-ERROR:  relation "cmdata1" does not exist
-LINE 1: INSERT INTO cmdata1 SELECT large_val() || repeat('a', 4000);
-                    ^
-SELECT pg_column_compression(f1) FROM cmdata1;
-ERROR:  relation "cmdata1" does not exist
-LINE 1: SELECT pg_column_compression(f1) FROM cmdata1;
-                                              ^
-SELECT SUBSTR(f1, 200, 5) FROM cmdata1;
-ERROR:  relation "cmdata1" does not exist
-LINE 1: SELECT SUBSTR(f1, 200, 5) FROM cmdata1;
-                                       ^
-SELECT SUBSTR(f1, 200, 5) FROM cmdata2;
- substr 
---------
- 79026
-(1 row)
-
-DROP TABLE cmdata2;
---test column type update varlena/non-varlena
-CREATE TABLE cmdata2 (f1 int);
-\d+ cmdata2
-                                         Table "public.cmdata2"
- Column |  Type   | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
---------+---------+-----------+----------+---------+---------+-------------+--------------+-------------
- f1     | integer |           |          |         | plain   |             |              | 
-
-ALTER TABLE cmdata2 ALTER COLUMN f1 TYPE varchar;
-\d+ cmdata2
-                                              Table "public.cmdata2"
- Column |       Type        | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+-------------------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | character varying |           |          |         | extended |             |              | 
-
-ALTER TABLE cmdata2 ALTER COLUMN f1 TYPE int USING f1::integer;
-\d+ cmdata2
-                                         Table "public.cmdata2"
- Column |  Type   | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
---------+---------+-----------+----------+---------+---------+-------------+--------------+-------------
- f1     | integer |           |          |         | plain   |             |              | 
-
---changing column storage should not impact the compression method
---but the data should not be compressed
-ALTER TABLE cmdata2 ALTER COLUMN f1 TYPE varchar;
-ALTER TABLE cmdata2 ALTER COLUMN f1 SET COMPRESSION pglz;
-\d+ cmdata2
-                                              Table "public.cmdata2"
- Column |       Type        | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+-------------------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | character varying |           |          |         | extended | pglz        |              | 
-
-ALTER TABLE cmdata2 ALTER COLUMN f1 SET STORAGE plain;
-\d+ cmdata2
-                                              Table "public.cmdata2"
- Column |       Type        | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
---------+-------------------+-----------+----------+---------+---------+-------------+--------------+-------------
- f1     | character varying |           |          |         | plain   | pglz        |              | 
-
-INSERT INTO cmdata2 VALUES (repeat('123456789', 800));
-SELECT pg_column_compression(f1) FROM cmdata2;
- pg_column_compression 
------------------------
- 
-(1 row)
-
--- test compression with materialized view
-CREATE MATERIALIZED VIEW compressmv(x) AS SELECT * FROM cmdata1;
-ERROR:  relation "cmdata1" does not exist
-LINE 1: ...TE MATERIALIZED VIEW compressmv(x) AS SELECT * FROM cmdata1;
-                                                               ^
-\d+ compressmv
-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 compressmv;
-ERROR:  relation "compressmv" does not exist
-LINE 1: SELECT pg_column_compression(x) FROM compressmv;
-                                             ^
--- test compression with partition
-CREATE TABLE cmpart(f1 text COMPRESSION lz4) PARTITION BY HASH(f1);
-ERROR:  compression method lz4 not supported
-DETAIL:  This functionality requires the server to be 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 cmpart1;
-ERROR:  relation "cmpart1" does not exist
-LINE 1: SELECT pg_column_compression(f1) FROM cmpart1;
-                                              ^
-SELECT pg_column_compression(f1) FROM cmpart2;
- pg_column_compression 
------------------------
-(0 rows)
-
--- test compression with inheritance
-CREATE TABLE cminh() INHERITS(cmdata, cmdata1); -- error
-ERROR:  relation "cmdata1" does not exist
-CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata); -- error
-NOTICE:  merging column "f1" with inherited definition
-ERROR:  column "f1" has a compression method conflict
-DETAIL:  pglz versus lz4
-CREATE TABLE cmdata3(f1 text);
-CREATE TABLE cminh() INHERITS (cmdata, cmdata3);
-NOTICE:  merging multiple inherited definitions of column "f1"
--- test default_toast_compression GUC
-SET default_toast_compression = '';
-ERROR:  invalid value for parameter "default_toast_compression": ""
-HINT:  Available values: pglz.
-SET default_toast_compression = 'I do not exist compression';
-ERROR:  invalid value for parameter "default_toast_compression": "I do not exist compression"
-HINT:  Available values: pglz.
-SET default_toast_compression = 'lz4';
-ERROR:  invalid value for parameter "default_toast_compression": "lz4"
-HINT:  Available values: pglz.
-SET default_toast_compression = 'pglz';
--- test alter compression method
-ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
-ERROR:  compression method lz4 not supported
-DETAIL:  This functionality requires the server to be built with lz4 support.
-INSERT INTO cmdata VALUES (repeat('123456789', 4004));
-\d+ cmdata
-                                        Table "public.cmdata"
- Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
---------+------+-----------+----------+---------+----------+-------------+--------------+-------------
- f1     | text |           |          |         | extended | pglz        |              | 
-Indexes:
-    "idx" btree (f1)
-Child tables: cminh
-
-SELECT pg_column_compression(f1) FROM cmdata;
- pg_column_compression 
------------------------
- pglz
- pglz
-(2 rows)
-
-ALTER TABLE cmdata2 ALTER COLUMN f1 SET COMPRESSION default;
-\d+ cmdata2
-                                              Table "public.cmdata2"
- Column |       Type        | Collation | Nullable | Default | Storage | Compression | Stats target | Description 
---------+-------------------+-----------+----------+---------+---------+-------------+--------------+-------------
- f1     | character varying |           |          |         | plain   |             |              | 
-
--- test alter compression method for materialized views
-ALTER MATERIALIZED VIEW compressmv ALTER COLUMN x SET COMPRESSION lz4;
-ERROR:  relation "compressmv" does not exist
-\d+ compressmv
--- test alter compression method for partitioned tables
-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:  compression method lz4 not supported
-DETAIL:  This functionality requires the server to be built with lz4 support.
--- new data should be compressed with the current compression method
-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 cmpart1;
-ERROR:  relation "cmpart1" does not exist
-LINE 1: SELECT pg_column_compression(f1) FROM cmpart1;
-                                              ^
-SELECT pg_column_compression(f1) FROM cmpart2;
- pg_column_compression 
------------------------
-(0 rows)
-
--- VACUUM FULL does not recompress
-SELECT pg_column_compression(f1) FROM cmdata;
- pg_column_compression 
------------------------
- pglz
- pglz
-(2 rows)
-
-VACUUM FULL cmdata;
-SELECT pg_column_compression(f1) FROM cmdata;
- pg_column_compression 
------------------------
- pglz
- pglz
-(2 rows)
-
--- test expression index
-DROP TABLE cmdata2;
-CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
-ERROR:  compression method lz4 not supported
-DETAIL:  This functionality requires the server to be built with lz4 support.
-CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
-ERROR:  relation "cmdata2" does not exist
-INSERT INTO cmdata2 VALUES((SELECT array_agg(fipshash(g::TEXT))::TEXT FROM
-generate_series(1, 50) g), VERSION());
-ERROR:  relation "cmdata2" does not exist
-LINE 1: INSERT INTO cmdata2 VALUES((SELECT array_agg(fipshash(g::TEX...
-                    ^
--- check data is ok
-SELECT length(f1) FROM cmdata;
- length 
---------
-  10000
-  36036
-(2 rows)
-
-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 
---------
-  10040
-(1 row)
-
-SELECT length(f1) FROM cmmove3;
- length 
---------
-  10000
-(1 row)
-
-CREATE TABLE badcompresstbl (a text COMPRESSION I_Do_Not_Exist_Compression); -- fails
-ERROR:  invalid compression method "i_do_not_exist_compression"
-CREATE TABLE badcompresstbl (a text);
-ALTER TABLE badcompresstbl ALTER a SET COMPRESSION I_Do_Not_Exist_Compression; -- fails
-ERROR:  invalid compression method "i_do_not_exist_compression"
-DROP TABLE badcompresstbl;
-\set HIDE_TOAST_COMPRESSION true

src/test/regress/expected/compression_lz4.out

@@ -0,0 +1,249 @@
+-- Tests for TOAST compression with lz4
+SELECT NOT(enumvals @> '{lz4}') AS skip_test FROM pg_settings WHERE
+  name = 'default_toast_compression' \gset
+\if :skip_test
+   \echo '*** skipping TOAST tests with lz4 (not supported) ***'
+   \quit
+\endif
+CREATE SCHEMA lz4;
+SET search_path TO lz4, public;
+\set HIDE_TOAST_COMPRESSION false
+-- Ensure we get stable results regardless of the installation's default.
+-- We rely on this GUC value for a few tests.
+SET default_toast_compression = 'pglz';
+-- test creating table with compression method
+CREATE TABLE cmdata_pglz(f1 text COMPRESSION pglz);
+CREATE INDEX idx ON cmdata_pglz(f1);
+INSERT INTO cmdata_pglz VALUES(repeat('1234567890', 1000));
+\d+ cmdata
+CREATE TABLE cmdata_lz4(f1 TEXT COMPRESSION lz4);
+INSERT INTO cmdata_lz4 VALUES(repeat('1234567890', 1004));
+\d+ cmdata1
+-- verify stored compression method in the data
+SELECT pg_column_compression(f1) FROM cmdata_lz4;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+-- decompress data slice
+SELECT SUBSTR(f1, 200, 5) FROM cmdata_pglz;
+ substr 
+--------
+ 01234
+(1 row)
+
+SELECT SUBSTR(f1, 2000, 50) FROM cmdata_lz4;
+                       substr                       
+----------------------------------------------------
+ 01234567890123456789012345678901234567890123456789
+(1 row)
+
+-- copy with table creation
+SELECT * INTO cmmove1 FROM cmdata_lz4;
+\d+ cmmove1
+                                         Table "lz4.cmmove1"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended |             |              | 
+
+SELECT pg_column_compression(f1) FROM cmmove1;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+-- test LIKE INCLUDING COMPRESSION.  The GUC default_toast_compression
+-- has no effect, the compression method from the table being copied.
+CREATE TABLE cmdata2 (LIKE cmdata_lz4 INCLUDING COMPRESSION);
+\d+ cmdata2
+                                         Table "lz4.cmdata2"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ f1     | text |           |          |         | extended | lz4         |              | 
+
+DROP TABLE cmdata2;
+-- copy to existing table
+CREATE TABLE cmmove3(f1 text COMPRESSION pglz);
+INSERT INTO cmmove3 SELECT * FROM cmdata_pglz;
+INSERT INTO cmmove3 SELECT * FROM cmdata_lz4;
+SELECT pg_column_compression(f1) FROM cmmove3;
+ pg_column_compression 
+-----------------------
+ pglz
+ lz4
+(2 rows)
+
+-- update using datum from different table with LZ4 data.
+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_lz4.f1 FROM cmdata_lz4;
+SELECT pg_column_compression(f1) FROM cmmove2;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+-- test externally stored compressed data
+CREATE OR REPLACE FUNCTION large_val_lz4() RETURNS TEXT LANGUAGE SQL AS
+'select array_agg(fipshash(g::text))::text from generate_series(1, 256) g';
+CREATE TABLE cmdata2 (f1 text COMPRESSION lz4);
+INSERT INTO cmdata2 SELECT large_val_lz4() || repeat('a', 4000);
+SELECT pg_column_compression(f1) FROM cmdata2;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+SELECT SUBSTR(f1, 200, 5) FROM cmdata2;
+ substr 
+--------
+ 79026
+(1 row)
+
+DROP TABLE cmdata2;
+DROP FUNCTION large_val_lz4;
+-- test compression with materialized view
+CREATE MATERIALIZED VIEW compressmv(x) AS SELECT * FROM cmdata_lz4;
+\d+ compressmv
+                                  Materialized view "lz4.compressmv"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ x      | text |           |          |         | extended |             |              | 
+View definition:
+ SELECT f1 AS x
+   FROM cmdata_lz4;
+
+SELECT pg_column_compression(f1) FROM cmdata_lz4;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+SELECT pg_column_compression(x) FROM compressmv;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+-- 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 cmpart1;
+ pg_column_compression 
+-----------------------
+ lz4
+(1 row)
+
+SELECT pg_column_compression(f1) FROM cmpart2;
+ pg_column_compression 
+-----------------------
+ pglz
+(1 row)
+
+-- test compression with inheritance
+CREATE TABLE cminh() INHERITS(cmdata_pglz, cmdata_lz4); -- error
+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_pglz); -- error
+NOTICE:  merging column "f1" with inherited definition
+ERROR:  column "f1" has a compression method conflict
+DETAIL:  pglz versus lz4
+CREATE TABLE cmdata3(f1 text);
+CREATE TABLE cminh() INHERITS (cmdata_pglz, cmdata3);
+NOTICE:  merging multiple inherited definitions of column "f1"
+-- test default_toast_compression GUC
+SET default_toast_compression = 'lz4';
+-- test alter compression method
+ALTER TABLE cmdata_pglz ALTER COLUMN f1 SET COMPRESSION lz4;
+INSERT INTO cmdata_pglz VALUES (repeat('123456789', 4004));
+\d+ cmdata
+SELECT pg_column_compression(f1) FROM cmdata_pglz;
+ pg_column_compression 
+-----------------------
+ pglz
+ lz4
+(2 rows)
+
+ALTER TABLE cmdata_pglz ALTER COLUMN f1 SET COMPRESSION pglz;
+-- test alter compression method for materialized views
+ALTER MATERIALIZED VIEW compressmv ALTER COLUMN x SET COMPRESSION lz4;
+\d+ compressmv
+                                  Materialized view "lz4.compressmv"
+ Column | Type | Collation | Nullable | Default | Storage  | Compression | Stats target | Description 
+--------+------+-----------+----------+---------+----------+-------------+--------------+-------------
+ x      | text |           |          |         | extended | lz4         |              | 
+View definition:
+ SELECT f1 AS x
+   FROM cmdata_lz4;
+
+-- test alter compression method for partitioned tables
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+-- new data should be compressed with the current compression method
+INSERT INTO cmpart VALUES (repeat('123456789', 1004));
+INSERT INTO cmpart VALUES (repeat('123456789', 4004));
+SELECT pg_column_compression(f1) FROM cmpart1;
+ pg_column_compression 
+-----------------------
+ lz4
+ pglz
+(2 rows)
+
+SELECT pg_column_compression(f1) FROM cmpart2;
+ pg_column_compression 
+-----------------------
+ pglz
+ lz4
+(2 rows)
+
+-- test expression index
+CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
+CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
+INSERT INTO cmdata2 VALUES((SELECT array_agg(fipshash(g::TEXT))::TEXT FROM
+generate_series(1, 50) g), VERSION());
+-- check data is ok
+SELECT length(f1) FROM cmdata_pglz;
+ length 
+--------
+  10000
+  36036
+(2 rows)
+
+SELECT length(f1) FROM cmdata_lz4;
+ length 
+--------
+  10040
+(1 row)
+
+SELECT length(f1) FROM cmmove1;
+ length 
+--------
+  10040
+(1 row)
+
+SELECT length(f1) FROM cmmove2;
+ length 
+--------
+  10040
+(1 row)
+
+SELECT length(f1) FROM cmmove3;
+ length 
+--------
+  10000
+  10040
+(2 rows)
+
+\set HIDE_TOAST_COMPRESSION true

src/test/regress/expected/compression_lz4_1.out

@@ -0,0 +1,7 @@
+-- Tests for TOAST compression with lz4
+SELECT NOT(enumvals @> '{lz4}') AS skip_test FROM pg_settings WHERE
+  name = 'default_toast_compression' \gset
+\if :skip_test
+   \echo '*** skipping TOAST tests with lz4 (not supported) ***'
+*** skipping TOAST tests with lz4 (not supported) ***
+   \quit

src/test/regress/parallel_schedule

@@ -123,7 +123,7 @@ test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion tr
 # The stats test resets stats, so nothing else needing stats access can be in
 # this group.
 # ----------
-test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize stats predicate numa
+test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression compression_lz4 memoize stats predicate numa
 
 # event_trigger depends on create_am and cannot run concurrently with
 # any test that runs DDL

src/test/regress/sql/compression.sql

@@ -1,3 +1,8 @@
+-- Default set of tests for TOAST compression, independent on compression
+-- methods supported by the build.
+
+CREATE SCHEMA pglz;
+SET search_path TO pglz, public;
 \set HIDE_TOAST_COMPRESSION false
 
 -- ensure we get stable results regardless of installation's default
@@ -8,53 +13,27 @@ 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
 
 -- verify stored compression method in the data
 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;
 \d+ cmmove1
 SELECT pg_column_compression(f1) FROM cmmove1;
 
--- 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 cmmove3;
-
--- test LIKE INCLUDING COMPRESSION
-CREATE TABLE cmdata2 (LIKE cmdata1 INCLUDING COMPRESSION);
-\d+ cmdata2
-DROP TABLE cmdata2;
-
 -- try setting compression for incompressible data type
 CREATE TABLE cmdata2 (f1 int COMPRESSION pglz);
 
--- 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 = cmdata1.f1 FROM cmdata1;
-SELECT pg_column_compression(f1) FROM cmmove2;
-
 -- test externally stored compressed data
 CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS
 'select array_agg(fipshash(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 large_val() || repeat('a', 4000);
-SELECT pg_column_compression(f1) FROM cmdata1;
-SELECT SUBSTR(f1, 200, 5) FROM cmdata1;
 SELECT SUBSTR(f1, 200, 5) FROM cmdata2;
 DROP TABLE cmdata2;
 
@@ -76,76 +55,31 @@ ALTER TABLE cmdata2 ALTER COLUMN f1 SET STORAGE plain;
 INSERT INTO cmdata2 VALUES (repeat('123456789', 800));
 SELECT pg_column_compression(f1) FROM cmdata2;
 
--- test compression with materialized view
-CREATE MATERIALIZED VIEW compressmv(x) AS SELECT * FROM cmdata1;
-\d+ compressmv
-SELECT pg_column_compression(f1) FROM cmdata1;
-SELECT pg_column_compression(x) FROM compressmv;
-
--- 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 cmpart1;
-SELECT pg_column_compression(f1) FROM cmpart2;
-
 -- test compression with inheritance
-CREATE TABLE cminh() INHERITS(cmdata, cmdata1); -- error
-CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata); -- error
 CREATE TABLE cmdata3(f1 text);
 CREATE TABLE cminh() INHERITS (cmdata, cmdata3);
 
 -- test default_toast_compression GUC
+-- suppress machine-dependent details
+\set VERBOSITY terse
 SET default_toast_compression = '';
 SET default_toast_compression = 'I do not exist compression';
-SET default_toast_compression = 'lz4';
 SET default_toast_compression = 'pglz';
-
--- test alter compression method
-ALTER TABLE cmdata ALTER COLUMN f1 SET COMPRESSION lz4;
-INSERT INTO cmdata VALUES (repeat('123456789', 4004));
-\d+ cmdata
-SELECT pg_column_compression(f1) FROM cmdata;
+\set VERBOSITY default
 
 ALTER TABLE cmdata2 ALTER COLUMN f1 SET COMPRESSION default;
 \d+ cmdata2
 
--- test alter compression method for materialized views
-ALTER MATERIALIZED VIEW compressmv ALTER COLUMN x SET COMPRESSION lz4;
-\d+ compressmv
-
--- test alter compression method for partitioned tables
-ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
-ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
-
--- new data should be compressed with the current compression method
-INSERT INTO cmpart VALUES (repeat('123456789', 1004));
-INSERT INTO cmpart VALUES (repeat('123456789', 4004));
-SELECT pg_column_compression(f1) FROM cmpart1;
-SELECT pg_column_compression(f1) FROM cmpart2;
+DROP TABLE cmdata2;
 
 -- VACUUM FULL does not recompress
 SELECT pg_column_compression(f1) FROM cmdata;
 VACUUM FULL cmdata;
 SELECT pg_column_compression(f1) FROM cmdata;
 
--- test expression index
-DROP TABLE cmdata2;
-CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
-CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
-INSERT INTO cmdata2 VALUES((SELECT array_agg(fipshash(g::TEXT))::TEXT FROM
-generate_series(1, 50) g), VERSION());
-
 -- 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;
 
 CREATE TABLE badcompresstbl (a text COMPRESSION I_Do_Not_Exist_Compression); -- fails
 CREATE TABLE badcompresstbl (a text);

src/test/regress/sql/compression_lz4.sql

@@ -0,0 +1,129 @@
+-- Tests for TOAST compression with lz4
+
+SELECT NOT(enumvals @> '{lz4}') AS skip_test FROM pg_settings WHERE
+  name = 'default_toast_compression' \gset
+\if :skip_test
+   \echo '*** skipping TOAST tests with lz4 (not supported) ***'
+   \quit
+\endif
+
+CREATE SCHEMA lz4;
+SET search_path TO lz4, public;
+
+\set HIDE_TOAST_COMPRESSION false
+
+-- Ensure we get stable results regardless of the installation's default.
+-- We rely on this GUC value for a few tests.
+SET default_toast_compression = 'pglz';
+
+-- test creating table with compression method
+CREATE TABLE cmdata_pglz(f1 text COMPRESSION pglz);
+CREATE INDEX idx ON cmdata_pglz(f1);
+INSERT INTO cmdata_pglz VALUES(repeat('1234567890', 1000));
+\d+ cmdata
+CREATE TABLE cmdata_lz4(f1 TEXT COMPRESSION lz4);
+INSERT INTO cmdata_lz4 VALUES(repeat('1234567890', 1004));
+\d+ cmdata1
+
+-- verify stored compression method in the data
+SELECT pg_column_compression(f1) FROM cmdata_lz4;
+
+-- decompress data slice
+SELECT SUBSTR(f1, 200, 5) FROM cmdata_pglz;
+SELECT SUBSTR(f1, 2000, 50) FROM cmdata_lz4;
+
+-- copy with table creation
+SELECT * INTO cmmove1 FROM cmdata_lz4;
+\d+ cmmove1
+SELECT pg_column_compression(f1) FROM cmmove1;
+
+-- test LIKE INCLUDING COMPRESSION.  The GUC default_toast_compression
+-- has no effect, the compression method from the table being copied.
+CREATE TABLE cmdata2 (LIKE cmdata_lz4 INCLUDING COMPRESSION);
+\d+ cmdata2
+DROP TABLE cmdata2;
+
+-- copy to existing table
+CREATE TABLE cmmove3(f1 text COMPRESSION pglz);
+INSERT INTO cmmove3 SELECT * FROM cmdata_pglz;
+INSERT INTO cmmove3 SELECT * FROM cmdata_lz4;
+SELECT pg_column_compression(f1) FROM cmmove3;
+
+-- update using datum from different table with LZ4 data.
+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_lz4.f1 FROM cmdata_lz4;
+SELECT pg_column_compression(f1) FROM cmmove2;
+
+-- test externally stored compressed data
+CREATE OR REPLACE FUNCTION large_val_lz4() RETURNS TEXT LANGUAGE SQL AS
+'select array_agg(fipshash(g::text))::text from generate_series(1, 256) g';
+CREATE TABLE cmdata2 (f1 text COMPRESSION lz4);
+INSERT INTO cmdata2 SELECT large_val_lz4() || repeat('a', 4000);
+SELECT pg_column_compression(f1) FROM cmdata2;
+SELECT SUBSTR(f1, 200, 5) FROM cmdata2;
+DROP TABLE cmdata2;
+DROP FUNCTION large_val_lz4;
+
+-- test compression with materialized view
+CREATE MATERIALIZED VIEW compressmv(x) AS SELECT * FROM cmdata_lz4;
+\d+ compressmv
+SELECT pg_column_compression(f1) FROM cmdata_lz4;
+SELECT pg_column_compression(x) FROM compressmv;
+
+-- 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 cmpart1;
+SELECT pg_column_compression(f1) FROM cmpart2;
+
+-- test compression with inheritance
+CREATE TABLE cminh() INHERITS(cmdata_pglz, cmdata_lz4); -- error
+CREATE TABLE cminh(f1 TEXT COMPRESSION lz4) INHERITS(cmdata_pglz); -- error
+CREATE TABLE cmdata3(f1 text);
+CREATE TABLE cminh() INHERITS (cmdata_pglz, cmdata3);
+
+-- test default_toast_compression GUC
+SET default_toast_compression = 'lz4';
+
+-- test alter compression method
+ALTER TABLE cmdata_pglz ALTER COLUMN f1 SET COMPRESSION lz4;
+INSERT INTO cmdata_pglz VALUES (repeat('123456789', 4004));
+\d+ cmdata
+SELECT pg_column_compression(f1) FROM cmdata_pglz;
+ALTER TABLE cmdata_pglz ALTER COLUMN f1 SET COMPRESSION pglz;
+
+-- test alter compression method for materialized views
+ALTER MATERIALIZED VIEW compressmv ALTER COLUMN x SET COMPRESSION lz4;
+\d+ compressmv
+
+-- test alter compression method for partitioned tables
+ALTER TABLE cmpart1 ALTER COLUMN f1 SET COMPRESSION pglz;
+ALTER TABLE cmpart2 ALTER COLUMN f1 SET COMPRESSION lz4;
+
+-- new data should be compressed with the current compression method
+INSERT INTO cmpart VALUES (repeat('123456789', 1004));
+INSERT INTO cmpart VALUES (repeat('123456789', 4004));
+SELECT pg_column_compression(f1) FROM cmpart1;
+SELECT pg_column_compression(f1) FROM cmpart2;
+
+-- test expression index
+CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
+CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
+INSERT INTO cmdata2 VALUES((SELECT array_agg(fipshash(g::TEXT))::TEXT FROM
+generate_series(1, 50) g), VERSION());
+
+-- check data is ok
+SELECT length(f1) FROM cmdata_pglz;
+SELECT length(f1) FROM cmdata_lz4;
+SELECT length(f1) FROM cmmove1;
+SELECT length(f1) FROM cmmove2;
+SELECT length(f1) FROM cmmove3;
+
+\set HIDE_TOAST_COMPRESSION true