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Diffstat (limited to 'contrib/pageinspect/sql/checksum.sql')
| -rw-r--r-- | contrib/pageinspect/sql/checksum.sql | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/contrib/pageinspect/sql/checksum.sql b/contrib/pageinspect/sql/checksum.sql new file mode 100644 index 0000000..b877db0 --- /dev/null +++ b/contrib/pageinspect/sql/checksum.sql @@ -0,0 +1,31 @@ +-- +-- 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; + +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); |