xref: /sqlite-3.40.0/test/bestindex4.test (revision d96ab995) 
1# 2016 November 11
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# Test the virtual table interface. In particular the xBestIndex
12# method.
13#
14
15set testdir [file dirname $argv0]
16source $testdir/tester.tcl
17set testprefix bestindex4
18
19ifcapable !vtab {
20  finish_test
21  return
22}
23
24#-------------------------------------------------------------------------
25# Virtual table callback for a virtual table named $tbl.
26#
27# The table created is:
28#
29#      "CREATE TABLE t1 (id, host, class)"
30#
31# The virtual table supports == operators on a subset of its columns. The
32# exact subset depends on the value of bitmask paramater $param.
33#
34#   0x01 - == on "id" supported
35#   0x02 - == on "host" supported
36#   0x04 - == on "class" supported
37#
38# $param also supports the following bits:
39#
40#   0x08 - ignore the "usable" flag (malfunction)
41#
42#
43#
44proc vtab_cmd {param method args} {
45  switch -- $method {
46    xConnect {
47      return "CREATE TABLE t1(id TEXT, host TEXT, class TEXT)"
48    }
49
50    xBestIndex {
51      set hdl [lindex $args 0]
52      set clist [$hdl constraints]
53      set orderby [$hdl orderby]
54      set mask [$hdl mask]
55
56      set ret [list]
57
58      set use use
59
60
61      for {set i 0} {$i < [llength $clist]} {incr i} {
62        array unset C
63        array set C [lindex $clist $i]
64        if { ($C(usable) || ($param & 0x08))
65          && $C(op)=="eq" && ($param & 1<<$C(column))
66        } {
67          lappend ret $use $i
68          break
69        }
70      }
71
72      set score 1000000
73      if {$ret!=""} {
74        set score [expr $score / [llength $ret]]
75      }
76      lappend ret cost $score rows $score
77
78      return $ret
79    }
80
81    xFilter {
82    }
83  }
84  return ""
85}
86
87register_tcl_module db
88
89for {set param1 0} {$param1<16} {incr param1} {
90  for {set param2 0} {$param2<16} {incr param2} {
91    reset_db
92    register_tcl_module db
93    do_execsql_test 1.$param1.$param2.1 "
94      CREATE VIRTUAL TABLE t1 USING tcl('vtab_cmd $param1');
95      CREATE VIRTUAL TABLE t2 USING tcl('vtab_cmd $param2');
96    "
97
98    foreach {tn sql} {
99      2 "select t1.id as ID from t1, t2 where t1.id=t2.host and t2.class='xx'"
100      3 {
101        select t1.id as ID from t1, t2 where t2.class ='xx' and t2.id = t1.host
102      }
103      4 {
104        select t1.id as ID from t1, t2 where t1.host = t2.id and t2. class ='xx'
105      }
106    } {
107
108      if {($param1 & 0x08)==0 && ($param2 & 0x08)==0} {
109
110        do_execsql_test 1.$param1.$param2.$tn.a $sql {}
111
112      } else {
113        do_test 1.$param1.$param2.$tn.b {
114          catchsql $sql
115            set {} {}
116        } {}
117      }
118    }
119
120  }
121}
122
123#-------------------------------------------------------------------------
124# Test that a parameter passed to a table-valued function cannot be
125# used to drive an index. i.e. that in the following:
126#
127#   SELECT * FROM tbl, vtab(tbl.x);
128#
129# The implicit constraint "tbl.x = vtab.hidden" is not optimized using
130# an index on tbl.x.
131#
132reset_db
133register_tcl_module db
134proc vtab_command {method args} {
135  switch -- $method {
136    xConnect {
137      return "CREATE TABLE t1(a, b, c, d HIDDEN)"
138    }
139
140    xBestIndex {
141      set hdl [lindex $args 0]
142      set clist [$hdl constraints]
143      set orderby [$hdl orderby]
144      set mask [$hdl mask]
145
146      if {[llength $clist]!=1} { error "unexpected constraint list" }
147      catch { array unset C }
148      array set C [lindex $clist 0]
149      if {$C(usable)} {
150        return [list omit 0 idxnum 555 rows 10 cost 100]
151      }
152      return [list cost 100000000]
153    }
154
155  }
156
157  return {}
158}
159
160do_execsql_test 2.0 {
161  CREATE VIRTUAL TABLE x1 USING tcl(vtab_command);
162  CREATE TABLE t1 (x INT PRIMARY KEY);
163} {}
164
165do_eqp_test 2.1 {
166  SELECT * FROM t1, x1 WHERE x1.d=t1.x;
167} {
168  QUERY PLAN
169  |--SCAN x1 VIRTUAL TABLE INDEX 0:
170  `--SEARCH t1 USING COVERING INDEX sqlite_autoindex_t1_1 (x=?)
171}
172
173do_eqp_test 2.2 {
174  SELECT * FROM t1, x1(t1.x)
175} {
176  QUERY PLAN
177  |--SCAN t1
178  `--SCAN x1 VIRTUAL TABLE INDEX 555:
179}
180
181
182finish_test
183