14 lines
		
	
	
		
			498 B
		
	
	
	
		
			SQL
		
	
	
	
	
	
			
		
		
	
	
			14 lines
		
	
	
		
			498 B
		
	
	
	
		
			SQL
		
	
	
	
	
	
| # 有效行数的占比A1 = (10000-1000)/10000, A2 = (5000-1000)/5000
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| # 等值条件选择率B1 = A1*1/1000, B2 = A2*1/1000  
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| #table1 B1
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| #table2 B2
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| select * from t1,t2 where t1.c1 = t2.c1;
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| #table1  B1 + A1 * 1 - B1*A1
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| #table2 B2 + A1 * 1 - B2*A1
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| select * from t1,t2 where t1.c1 = t2.c1 or t1.c1 > 1;
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| select * from t1,t2 where t1.c1 = t2.c1 and t1.c1 > 1;
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| #DEFAULT_INEQ_SEL
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| select * from t1,t2 where t1.c1 < t2.c1; 
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| select * from t1,t2 where t1.c1 > t2.c1;
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| select * from t1,t2 where t1.c1 != t2.c1;
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