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Overview
Comment:Fix a problem with using stat4 data to estimate the number of rows scanned by a range constraint on the second or subsequent column of any index where an affinity transformation must be applied to the constraint argument.
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SHA1: c21f58d84859e479a6cc619671a0df48b2f9692e
User & Date: dan 2013-09-02 07:16:40.805
Context
2013-09-02
11:52
Add tests to check if ANALYZE is choosing common non-periodic samples for the stat4 table. (check-in: 175842997a user: dan tags: trunk)
07:16
Fix a problem with using stat4 data to estimate the number of rows scanned by a range constraint on the second or subsequent column of any index where an affinity transformation must be applied to the constraint argument. (check-in: c21f58d848 user: dan tags: trunk)
2013-08-31
18:36
Cleanup of the windows VFS, including added support for Cygwin, fixes for compiler warnings under unusual configurations, and improved diagnostic error messages. (check-in: c94933f132 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/where.c.
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  if( nEq==pBuilder->nRecValid
   && nEq<p->nSampleCol
   && p->nSample 
   && OptimizationEnabled(pParse->db, SQLITE_Stat3) 
  ){
    UnpackedRecord *pRec = pBuilder->pRec;
    tRowcnt a[2];




    u8 aff = p->pTable->aCol[p->aiColumn[0]].affinity;


    /* Variable iLower will be set to the estimate of the number of rows in 
    ** the index that are less than the lower bound of the range query. The
    ** lower bound being the concatenation of $P and $L, where $P is the
    ** key-prefix formed by the nEq values matched against the nEq left-most
    ** columns of the index, and $L is the value in pLower.
    **







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  if( nEq==pBuilder->nRecValid
   && nEq<p->nSampleCol
   && p->nSample 
   && OptimizationEnabled(pParse->db, SQLITE_Stat3) 
  ){
    UnpackedRecord *pRec = pBuilder->pRec;
    tRowcnt a[2];
    u8 aff;
    if( nEq==p->nColumn ){
      aff = SQLITE_AFF_INTEGER;
    }else{
      aff = p->pTable->aCol[p->aiColumn[nEq]].affinity;
    }

    /* Variable iLower will be set to the estimate of the number of rows in 
    ** the index that are less than the lower bound of the range query. The
    ** lower bound being the concatenation of $P and $L, where $P is the
    ** key-prefix formed by the nEq values matched against the nEq left-most
    ** columns of the index, and $L is the value in pLower.
    **
Changes to test/analyze9.test.
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    do_eqp_test 12.$tn.5 $sql {/t4 USING INDEX t4a/}
    set sql {
      SELECT * FROM t4 WHERE x=X'abcdef' AND a COLLATE nocase = 'abc' AND b = 3
    }
    do_eqp_test 12.$tn.6 $sql {/t4 USING INDEX t4a/}
  }
}
























































finish_test









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    do_eqp_test 12.$tn.5 $sql {/t4 USING INDEX t4a/}
    set sql {
      SELECT * FROM t4 WHERE x=X'abcdef' AND a COLLATE nocase = 'abc' AND b = 3
    }
    do_eqp_test 12.$tn.6 $sql {/t4 USING INDEX t4a/}
  }
}

#-------------------------------------------------------------------------
# Check that affinities are taken into account when using stat4 data to
# estimate the number of rows scanned by a rowid constraint.
#
drop_all_tables
do_test 13.1 {
  execsql {
    CREATE TABLE t1(a, b, c);
    CREATE INDEX i1 ON t1(a);
    CREATE INDEX i2 ON t1(b, c);
  }
  for {set i 0} {$i<100} {incr i} {
    if {$i %2} {set a abc} else {set a def}
    execsql { INSERT INTO t1(rowid, a, b, c) VALUES($i, $a, $i, $i) }
  }
  execsql ANALYZE
} {}
do_eqp_test 13.2.1 {
  SELECT * FROM t1 WHERE a='abc' AND rowid<15 AND b<20
} {/SEARCH TABLE t1 USING INDEX i1/}
do_eqp_test 13.2.2 {
  SELECT * FROM t1 WHERE a='abc' AND rowid<'15' AND b<20
} {/SEARCH TABLE t1 USING INDEX i1/}
do_eqp_test 13.3.1 {
  SELECT * FROM t1 WHERE a='abc' AND rowid<100 AND b<20
} {/SEARCH TABLE t1 USING INDEX i2/}
do_eqp_test 13.3.2 {
  SELECT * FROM t1 WHERE a='abc' AND rowid<'100' AND b<20
} {/SEARCH TABLE t1 USING INDEX i2/}

#-------------------------------------------------------------------------
# Check also that affinities are taken into account when using stat4 data 
# to estimate the number of rows scanned by any other constraint on a 
# column other than the leftmost.
#
drop_all_tables
do_test 14.1 {
  execsql { CREATE TABLE t1(a, b INTEGER, c) }
  for {set i 0} {$i<100} {incr i} {
    set c [expr $i % 3]
    execsql { INSERT INTO t1 VALUES('ott', $i, $c) }
  }
  execsql {
    CREATE INDEX i1 ON t1(a, b);
    CREATE INDEX i2 ON t1(c);
    ANALYZE;
  }
} {}
do_eqp_test 13.2.1 {
  SELECT * FROM t1 WHERE a='ott' AND b<10 AND c=1
} {/SEARCH TABLE t1 USING INDEX i1/}
do_eqp_test 13.2.2 {
  SELECT * FROM t1 WHERE a='ott' AND b<'10' AND c=1
} {/SEARCH TABLE t1 USING INDEX i1/}

finish_test