1# 2016 March 3 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 12set testdir [file dirname $argv0] 13source $testdir/tester.tcl 14set testprefix bestindex2 15 16ifcapable !vtab { 17 finish_test 18 return 19} 20 21#------------------------------------------------------------------------- 22# Virtual table callback for table named $tbl, with the columns specified 23# by list argument $cols. e.g. if the function is invoked as: 24# 25# vtab_cmd t1 {a b c} ... 26# 27# The table created is: 28# 29# "CREATE TABLE t1 (a, b, c)" 30# 31# The tables xBestIndex method behaves as if all possible combinations of 32# "=" constraints (but no others) may be optimized. The cost of a full table 33# scan is: 34# 35# "WHERE 1" "cost 1000000 rows 1000000" 36# 37# If one or more "=" constraints are in use, the cost and estimated number 38# of rows returned are both is (11 - nCons)*1000, where nCons is the number 39# of constraints used. e.g. 40# 41# "WHERE a=? AND b=?" -> "cost 900 rows 900" 42# "WHERE c=? AND b<?" -> "cost 1000 rows 1000" 43# 44proc vtab_cmd {tbl cols method args} { 45 switch -- $method { 46 xConnect { 47 return "CREATE TABLE $tbl ([join $cols ,])" 48 } 49 xBestIndex { 50 foreach {clist orderby mask} $args {} 51 52 set cons [list] 53 set used [list] 54 55 for {set i 0} {$i < [llength $clist]} {incr i} { 56 array unset C 57 array set C [lindex $clist $i] 58 if {$C(op)=="eq" && $C(usable) && [lsearch $cons $C(column)]<0} { 59 lappend used use $i 60 lappend cons $C(column) 61 } 62 } 63 64 set nCons [llength $cons] 65 if {$nCons==0} { 66 return "cost 1000000 rows 1000000" 67 } else { 68 set cost [expr (11-$nCons) * 1000] 69 set ret [concat $used "cost $cost rows $cost"] 70 71 set txt [list] 72 foreach c $cons { lappend txt "[lindex $cols $c]=?" } 73 lappend ret idxstr "indexed([join $txt { AND }])" 74 75 return $ret 76 } 77 } 78 } 79 return "" 80} 81 82register_tcl_module db 83 84do_execsql_test 1.0 { 85 CREATE VIRTUAL TABLE t1 USING tcl("vtab_cmd t1 {a b}"); 86 CREATE VIRTUAL TABLE t2 USING tcl("vtab_cmd t2 {c d}"); 87 CREATE VIRTUAL TABLE t3 USING tcl("vtab_cmd t3 {e f}"); 88} 89 90do_eqp_test 1.1 { 91 SELECT * FROM t1 WHERE a='abc' 92} { 93 0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 0:indexed(a=?)} 94} 95do_eqp_test 1.2 { 96 SELECT * FROM t1 WHERE a='abc' AND b='def' 97} { 98 0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 0:indexed(a=? AND b=?)} 99} 100do_eqp_test 1.3 { 101 SELECT * FROM t1 WHERE a='abc' AND a='def' 102} { 103 0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 0:indexed(a=?)} 104} 105do_eqp_test 1.4 { 106 SELECT * FROM t1,t2 WHERE c=a 107} { 108 0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 0:} 109 0 1 1 {SCAN TABLE t2 VIRTUAL TABLE INDEX 0:indexed(c=?)} 110} 111 112do_eqp_test 1.5 { 113 SELECT * FROM t1, t2 CROSS JOIN t3 WHERE t2.c = +t1.b AND t3.e=t2.d 114} { 115 0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 0:} 116 0 1 1 {SCAN TABLE t2 VIRTUAL TABLE INDEX 0:indexed(c=?)} 117 0 2 2 {SCAN TABLE t3 VIRTUAL TABLE INDEX 0:indexed(e=?)} 118} 119 120do_eqp_test 1.6 { 121 SELECT * FROM t1, t2, t3 WHERE t2.c = +t1.b AND t3.e = t2.d 122} { 123 0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 0:} 124 0 1 1 {SCAN TABLE t2 VIRTUAL TABLE INDEX 0:indexed(c=?)} 125 0 2 2 {SCAN TABLE t3 VIRTUAL TABLE INDEX 0:indexed(e=?)} 126} 127 128do_execsql_test 1.7.1 { 129 CREATE TABLE x1(a, b); 130} 131do_eqp_test 1.7.2 { 132 SELECT * FROM x1 CROSS JOIN t1, t2, t3 133 WHERE t1.a = t2.c AND t1.b = t3.e 134} { 135 0 0 0 {SCAN TABLE x1} 136 0 1 1 {SCAN TABLE t1 VIRTUAL TABLE INDEX 0:} 137 0 2 2 {SCAN TABLE t2 VIRTUAL TABLE INDEX 0:indexed(c=?)} 138 0 3 3 {SCAN TABLE t3 VIRTUAL TABLE INDEX 0:indexed(e=?)} 139} 140 141finish_test 142