x

(1 row)

DROP TABLE toasttest;

-- test with short varlenas (up to 126 data bytes reduced to a 1-byte header)

-- being toasted.

CREATE TABLE toasttest (f1 text, f2 text);

ALTER TABLE toasttest SET (toast_tuple_target = 128);

ALTER TABLE toasttest ALTER COLUMN f1 SET STORAGE EXTERNAL;

ALTER TABLE toasttest ALTER COLUMN f2 SET STORAGE EXTERNAL;

-- Here, the first value is a varlena large enough to make it toasted and

-- stored uncompressed. The second value is a short varlena, toasted

-- and stored uncompressed.

INSERT INTO toasttest values(repeat('1234', 1000), repeat('5678', 30));

SELECT reltoastrelid::regclass AS reltoastname FROM pg_class

WHERE oid = 'toasttest'::regclass \gset

-- There should be two values inserted in the toast relation.

SELECT count(*) FROM :reltoastname WHERE chunk_seq = 0;

count

-------

2

(1 row)

SELECT substr(f1, 5, 10) AS f1_data, substr(f2, 5, 10) AS f2_data

FROM toasttest;

f1_data | f2_data

------------+------------

1234123412 | 5678567856

(1 row)

SELECT pg_column_compression(f1) AS f1_comp, pg_column_compression(f2) AS f2_comp

FROM toasttest;

f1_comp | f2_comp

---------+---------

|

(1 row)

DROP TABLE toasttest;

--

-- test length

SELECT cFROM toasttest;

DROPTABLE toasttest;

CREATETABLEtoasttest (f1text, f2text);

ALTERTABLE toasttestSET (toast_tuple_target=128);

ALTERTABLE toasttest ALTER COLUMN f1SET STORAGE EXTERNAL;

ALTERTABLE toasttest ALTER COLUMN f2SET STORAGE EXTERNAL;

INSERT INTO toasttestvalues(repeat('1234',1000), repeat('5678',30));

SELECT reltoastrelid::regclassAS reltoastnameFROM pg_class

WHEREoid='toasttest'::regclass \gset

SELECTcount(*)FROM :reltoastnameWHERE chunk_seq=0;

SELECT substr(f1,5,10)AS f1_data, substr(f2,5,10)AS f2_data

FROM toasttest;

SELECT pg_column_compression(f1)AS f1_comp, pg_column_compression(f2)AS f2_comp

FROM toasttest;

DROPTABLE toasttest;