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	As a result of confusion about whether the "char" type is signed or unsigned, scans for index searches like "col < 'x'" or "col <= 'x'" would start at the middle of the index not the left end, thus missing many or all of the entries they should find. Fortunately, this is not a symptom of index corruption. It's only the search logic that is broken, and we can fix it without unpleasant side-effects. Per report from Jason Kim. This has been wrong since btree_gin's beginning, so back-patch to all supported branches. Discussion: https://postgr.es/m/20210810001649.htnltbh7c63re42p@jasonk.me
		
			
				
	
	
		
			45 lines
		
	
	
		
			588 B
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			45 lines
		
	
	
		
			588 B
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
set enable_seqscan=off;
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CREATE TABLE test_char (
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	i "char"
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);
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INSERT INTO test_char VALUES ('a'),('b'),('c'),('d'),('e'),('f');
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CREATE INDEX idx_char ON test_char USING gin (i);
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SELECT * FROM test_char WHERE i<'d'::"char" ORDER BY i;
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 i 
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---
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 a
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 b
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 c
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(3 rows)
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SELECT * FROM test_char WHERE i<='d'::"char" ORDER BY i;
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 i 
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---
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 a
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 b
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 c
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 d
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(4 rows)
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SELECT * FROM test_char WHERE i='d'::"char" ORDER BY i;
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 i 
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---
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 d
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(1 row)
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SELECT * FROM test_char WHERE i>='d'::"char" ORDER BY i;
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 i 
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---
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 d
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 e
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 f
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(3 rows)
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SELECT * FROM test_char WHERE i>'d'::"char" ORDER BY i;
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 i 
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---
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 e
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 f
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(2 rows)
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