SQLite

      n = sqlite3ValueBytes(pVal, pColl->enc);

      for(i=0; i<SQLITE_INDEX_SAMPLES; i++){
        int r;
        int eSampletype = aSample[i].eType;
        if( eSampletype==SQLITE_NULL || eSampletype<eType ) continue;
        if( (eSampletype!=eType) ) break;
#ifndef SQLITE_OMIT_UTF16
        if( pColl->enc!=SQLITE_UTF8 ){


          int nSample;
          char *zSample = sqlite3Utf8to16(
              db, pColl->enc, aSample[i].u.z, aSample[i].nByte, &nSample
          );
          if( !zSample ){
            assert( db->mallocFailed );
            return SQLITE_NOMEM;
          }
          r = pColl->xCmp(pColl->pUser, nSample, zSample, n, z);
          sqlite3DbFree(db, zSample);
        }else
#endif
        {
          r = pColl->xCmp(pColl->pUser, aSample[i].nByte, aSample[i].u.z, n, z);
        }
        if( r>0 ) break;
      }
    }

    assert( i>=0 && i<=SQLITE_INDEX_SAMPLES );
    *piRegion = i;

do_test analyze2-4.4 {
  eqp "SELECT * FROM t3 WHERE a > 'A' AND a < 'C' AND b > 'A' AND b < 'C'"
} {0 0 {TABLE t3 WITH INDEX t3b}}
do_test analyze2-4.5 {
  eqp "SELECT * FROM t3 WHERE a > 'A' AND a < 'c' AND b > 'A' AND b < 'c'"
} {0 0 {TABLE t3 WITH INDEX t3a}}

ifcapable utf16 {
  proc test_collate {enc lhs rhs} {
    # puts $enc
    return [string compare $lhs $rhs]
  }
  do_test analyze2-5.1 {
    add_test_collate db 0 0 1
    execsql { CREATE TABLE t4(x COLLATE test_collate) }
    execsql { CREATE INDEX t4x ON t4(x) }
    set alphabet [list a b c d e f g h i j]
    execsql BEGIN
    for {set i 0} {$i < 1000} {incr i} {
      set str    [lindex $alphabet [expr ($i/100)%10]] 
      append str [lindex $alphabet [expr ($i/ 10)%10]]
      append str [lindex $alphabet [expr ($i/  1)%10]]
      execsql { INSERT INTO t4 VALUES($str) }
    }
    execsql COMMIT
    execsql ANALYZE
  } {}
  do_test analyze2-5.2 {
    execsql { 
      SELECT tbl,idx,group_concat(sample,' ') 
      FROM sqlite_stat2 
      WHERE tbl = 't4' 
      GROUP BY tbl,idx
    }
  } {t4 t4x {afa bej cej dej eej fej gej hej iej jej}}
  do_test analyze2-5.3 {
    eqp "SELECT * FROM t4 WHERE x>'ccc'"
  } {0 0 {TABLE t4 WITH INDEX t4x}}
  do_test analyze2-5.4 {
    eqp "SELECT * FROM t4 AS t41, t4 AS t42 WHERE t41.x>'ccc' AND t42.x>'ggg'"
  } {0 1 {TABLE t4 AS t42 WITH INDEX t4x} 1 0 {TABLE t4 AS t41 WITH INDEX t4x}}
  do_test analyze2-5.5 {
    eqp "SELECT * FROM t4 AS t41, t4 AS t42 WHERE t41.x>'ddd' AND t42.x>'ccc'"
  } {0 0 {TABLE t4 AS t41 WITH INDEX t4x} 1 1 {TABLE t4 AS t42 WITH INDEX t4x}}
}

#--------------------------------------------------------------------
# These tests, analyze2-6.*, verify that the library behaves correctly
# when one of the sqlite_stat1 and sqlite_stat2 tables is missing.
#
# If the sqlite_stat1 table is not present, then the sqlite_stat2
# table is not read. However, if it is the sqlite_stat2 table that
# is missing, the data in the sqlite_stat1 table is still used.
#
# Tests analyze2-6.1.* test the libary when the sqlite_stat2 table
# is missing. Tests analyze2-6.2.* test the library when sqlite_stat1
# is not present.
#
do_test analyze2-6.0 {
  execsql {
    DROP TABLE IF EXISTS t4;
    CREATE TABLE t5(a, b); CREATE INDEX t5i ON t5(a, b);
    CREATE TABLE t6(a, b); CREATE INDEX t6i ON t6(a, b);
  }
  for {set ii 0} {$ii < 20} {incr ii} {
    execsql {
      INSERT INTO t5 VALUES($ii, $ii);
      INSERT INTO t6 VALUES($ii/10, $ii/10);