61 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| # 2009 March 28
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| #
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| # The author disclaims copyright to this source code.  In place of
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| # a legal notice, here is a blessing:
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| #
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| #    May you do good and not evil.
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| #    May you find forgiveness for yourself and forgive others.
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| #    May you share freely, never taking more than you give.
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| #
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| #***********************************************************************
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| #
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| # Ticket #3757:  The cost functions on the query optimizer for the
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| # IN operator can be improved.
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| #
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| # $Id: tkt3757.test,v 1.1 2009/03/29 00:13:04 drh Exp $
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| 
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| set testdir [file dirname $argv0]
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| source $testdir/tester.tcl
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| 
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| # Evaluate SQL.  Return the result set followed by the
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| # and the number of full-scan steps.
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| #
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| proc count_steps {sql} {
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|   set r [db eval $sql]
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|   lappend r scan [db status step] sort [db status sort]
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| }
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| 
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| # Construct tables
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| #
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| do_test tkt3757-1.1 {
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|   db eval {
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|      CREATE TABLE t1(x INTEGER, y INTEGER, z TEXT);
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|      CREATE INDEX t1i1 ON t1(y,z);
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|      INSERT INTO t1 VALUES(1,2,'three');
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|      CREATE TABLE t2(a INTEGER, b TEXT);
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|      INSERT INTO t2 VALUES(2, 'two');
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|      ANALYZE;
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|      SELECT * FROM sqlite_stat1 ORDER BY 1, 2;
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|   }
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| } {t1 t1i1 {1 1 1} t2 {} 1}
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| 
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| # Modify statistics in order to make the optimizer then that:
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| #
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| #   (1)  Table T1 has about 250K entries
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| #   (2)  There are only about 5 distinct values of T1.
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| #
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| # Then run a query with "t1.y IN (SELECT ..)" in the WHERE clause.
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| # Make sure the index is used.
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| #
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| do_test tkt3757-1.2 {
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|   db eval {
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|     DELETE FROM sqlite_stat1;
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|     INSERT INTO sqlite_stat1 VALUES('t1','t1i1','250000 50000 30');
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|   }
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|   count_steps {
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|     SELECT * FROM t1 WHERE y IN (SELECT a FROM t2)
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|   }
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| } {1 2 three scan 0 sort 0}
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| 
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| finish_test
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