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--
-- Verify correct calculation of checksums
--
-- Postgres' checksum algorithm produces different answers on little-endian
-- and big-endian machines. The results of this test also vary depending
-- on the configured block size. This test has several different expected
-- results files to handle the following possibilities:
--
-- BLCKSZ end file
-- 8K LE checksum.out
-- 8K BE checksum_1.out
--
-- In future we might provide additional expected-results files for other
-- block sizes, but there seems little point as long as so many other
-- test scripts also show false failures for non-default block sizes.
--
-- This is to label the results files with blocksize:
SHOW block_size;
block_size
------------
8192
(1 row)
SHOW block_size \gset
-- Apply page_checksum() to some different data patterns and block numbers
SELECT blkno,
page_checksum(decode(repeat('01', :block_size), 'hex'), blkno) AS checksum_01,
page_checksum(decode(repeat('04', :block_size), 'hex'), blkno) AS checksum_04,
page_checksum(decode(repeat('ff', :block_size), 'hex'), blkno) AS checksum_ff,
page_checksum(decode(repeat('abcd', :block_size / 2), 'hex'), blkno) AS checksum_abcd,
page_checksum(decode(repeat('e6d6', :block_size / 2), 'hex'), blkno) AS checksum_e6d6,
page_checksum(decode(repeat('4a5e', :block_size / 2), 'hex'), blkno) AS checksum_4a5e
FROM generate_series(0, 100, 50) AS a (blkno);
blkno | checksum_01 | checksum_04 | checksum_ff | checksum_abcd | checksum_e6d6 | checksum_4a5e
-------+-------------+-------------+-------------+---------------+---------------+---------------
0 | -16327 | 8766 | -2722 | 13757 | -11485 | -31426
50 | -16281 | 8780 | -2708 | 13771 | -11503 | -31440
100 | -16235 | 8866 | -2758 | 13721 | -11577 | -31518
(3 rows)
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