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Artifact 39d014a90b67169f8482ede8713bff694761d879:


# 2014-04-26
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# 

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix cost


do_execsql_test 1.1 {
  CREATE TABLE t3(id INTEGER PRIMARY KEY, b NOT NULL);
  CREATE TABLE t4(c, d, e);
  CREATE UNIQUE INDEX i3 ON t3(b);
  CREATE UNIQUE INDEX i4 ON t4(c, d);
}
do_eqp_test 1.2 {
  SELECT e FROM t3, t4 WHERE b=c ORDER BY b, d;
} {
  0 0 0 {SCAN TABLE t3 USING COVERING INDEX i3} 
  0 1 1 {SEARCH TABLE t4 USING INDEX i4 (c=?)}
}


do_execsql_test 2.1 {
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a);
}

# It is better to use an index for ORDER BY than sort externally, even 
# if the index is a non-covering index.
do_eqp_test 2.2 {
  SELECT * FROM t1 ORDER BY a;
} {
  0 0 0 {SCAN TABLE t1 USING INDEX i1}
}

do_execsql_test 3.1 {
  CREATE TABLE t5(a INTEGER PRIMARY KEY,b,c,d,e,f,g);
  CREATE INDEX t5b ON t5(b);
  CREATE INDEX t5c ON t5(c);
  CREATE INDEX t5d ON t5(d);
  CREATE INDEX t5e ON t5(e);
  CREATE INDEX t5f ON t5(f);
  CREATE INDEX t5g ON t5(g);
}

do_eqp_test 3.2 {
  SELECT a FROM t5 
  WHERE b IS NULL OR c IS NULL OR d IS NULL 
  ORDER BY a;
} {
  0 0 0 {SEARCH TABLE t5 USING INDEX t5b (b=?)} 
  0 0 0 {SEARCH TABLE t5 USING INDEX t5c (c=?)} 
  0 0 0 {SEARCH TABLE t5 USING INDEX t5d (d=?)} 
  0 0 0 {USE TEMP B-TREE FOR ORDER BY}
}

#-------------------------------------------------------------------------
# If there is no likelihood() or stat3 data, SQLite assumes that a closed
# range scan (e.g. one constrained by "col BETWEEN ? AND ?" constraint)
# visits 1/16 of the rows in a table.
#
# Note: 1/17 =~ 0.058
# Note: 1/15 =~ 0.067
#
reset_db
do_execsql_test 4.1 {
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a);
  CREATE INDEX i2 ON t1(b);
}
do_eqp_test 4.2 {
  SELECT * FROM t1 WHERE likelihood(a=?, 0.058) AND b BETWEEN ? AND ?;
} {
  0 0 0 {SEARCH TABLE t1 USING INDEX i1 (a=?)}
}
do_eqp_test 4.3 {
  SELECT * FROM t1 WHERE likelihood(a=?, 0.067) AND b BETWEEN ? AND ?;
} {
  0 0 0 {SEARCH TABLE t1 USING INDEX i2 (b>? AND b<?)}
}


finish_test