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	This extends GiST's support for nearest-neighbor searches to many of the standard data types. Teodor Sigaev
		
			
				
	
	
		
			92 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			92 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| -- int2 check
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| CREATE TABLE int2tmp (a int2);
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| \copy int2tmp from 'data/int2.data'
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| SET enable_seqscan=on;
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| SELECT count(*) FROM int2tmp WHERE a <  237;
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|  count 
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| -------
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|    297
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a <= 237;
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|  count 
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| -------
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|    298
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a  = 237;
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|  count 
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| -------
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|      1
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a >= 237;
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|  count 
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| -------
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|    249
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a >  237;
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|  count 
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| -------
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|    248
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| (1 row)
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| 
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| SELECT a, a <-> '237' FROM int2tmp ORDER BY a <-> '237' LIMIT 3;
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|   a  | ?column? 
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| -----+----------
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|  237 |        0
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|  232 |        5
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|  228 |        9
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| (3 rows)
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| 
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| CREATE INDEX int2idx ON int2tmp USING gist ( a );
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| SET enable_seqscan=off;
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| SELECT count(*) FROM int2tmp WHERE a <  237::int2;
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|  count 
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| -------
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|    297
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a <= 237::int2;
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|  count 
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| -------
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|    298
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a  = 237::int2;
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|  count 
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| -------
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|      1
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a >= 237::int2;
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|  count 
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| -------
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|    249
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| (1 row)
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| 
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| SELECT count(*) FROM int2tmp WHERE a >  237::int2;
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|  count 
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| -------
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|    248
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| (1 row)
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| 
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| EXPLAIN (COSTS OFF)
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| SELECT a, a <-> '237' FROM int2tmp ORDER BY a <-> '237' LIMIT 3;
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|                 QUERY PLAN                 
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| -------------------------------------------
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|  Limit
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|    ->  Index Scan using int2idx on int2tmp
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|          Order By: (a <-> 237::smallint)
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| (3 rows)
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| 
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| SELECT a, a <-> '237' FROM int2tmp ORDER BY a <-> '237' LIMIT 3;
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|   a  | ?column? 
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| -----+----------
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|  237 |        0
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|  232 |        5
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|  228 |        9
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| (3 rows)
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| 
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