125 lines
2.8 KiB
Plaintext
125 lines
2.8 KiB
Plaintext
# 2012 September 17
|
|
#
|
|
# 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.
|
|
#
|
|
#***********************************************************************
|
|
#
|
|
# Tests for the optimization which attempts to use a covering index
|
|
# for a full-table scan (under the theory that the index will be smaller
|
|
# and require less I/O and hence will run faster.)
|
|
#
|
|
|
|
set testdir [file dirname $argv0]
|
|
source $testdir/tester.tcl
|
|
|
|
set testprefix coveridxscan
|
|
|
|
do_test 1.1 {
|
|
db eval {
|
|
CREATE TABLE t1(a,b,c);
|
|
INSERT INTO t1 VALUES(5,4,3), (4,8,2), (3,2,1);
|
|
CREATE INDEX t1ab ON t1(a,b);
|
|
CREATE INDEX t1b ON t1(b);
|
|
SELECT a FROM t1;
|
|
}
|
|
# covering index used for the scan, hence values are increasing
|
|
} {3 4 5}
|
|
|
|
do_test 1.2 {
|
|
db eval {
|
|
SELECT a, c FROM t1;
|
|
}
|
|
# There is no covering index, hence the values are in rowid order
|
|
} {5 3 4 2 3 1}
|
|
|
|
do_test 1.3 {
|
|
db eval {
|
|
SELECT b FROM t1;
|
|
}
|
|
# Choice of two indices: use the one with fewest columns
|
|
} {2 4 8}
|
|
|
|
do_test 2.1 {
|
|
optimization_control db cover-idx-scan 0
|
|
db eval {SELECT a FROM t1}
|
|
# With the optimization turned off, output in rowid order
|
|
} {5 4 3}
|
|
do_test 2.2 {
|
|
db eval {SELECT a, c FROM t1}
|
|
} {5 3 4 2 3 1}
|
|
do_test 2.3 {
|
|
db eval {SELECT b FROM t1}
|
|
} {4 8 2}
|
|
|
|
db close
|
|
sqlite3_shutdown
|
|
sqlite3_config_cis 0
|
|
sqlite3 db test.db
|
|
|
|
do_test 3.1 {
|
|
db eval {SELECT a FROM t1}
|
|
# With the optimization configured off, output in rowid order
|
|
} {5 4 3}
|
|
do_test 3.2 {
|
|
db eval {SELECT a, c FROM t1}
|
|
} {5 3 4 2 3 1}
|
|
do_test 3.3 {
|
|
db eval {SELECT b FROM t1}
|
|
} {4 8 2}
|
|
|
|
db close
|
|
sqlite3_shutdown
|
|
sqlite3_config_cis 1
|
|
sqlite3 db test.db
|
|
|
|
# The CIS optimization is enabled again. Covering indices are once again
|
|
# used for all table scans.
|
|
do_test 4.1 {
|
|
db eval {SELECT a FROM t1}
|
|
} {3 4 5}
|
|
do_test 4.2 {
|
|
db eval {SELECT a, c FROM t1}
|
|
} {5 3 4 2 3 1}
|
|
do_test 4.3 {
|
|
db eval {SELECT b FROM t1}
|
|
} {2 4 8}
|
|
|
|
#-------------------------------------------------------------------------
|
|
# Test that indexes with large numbers of columns can be correctly
|
|
# identified as covering indexes.
|
|
reset_db
|
|
set L [list]
|
|
for {set i 1} {$i<120} {incr i} {
|
|
lappend L "c$i"
|
|
}
|
|
set cols [join $L ,]
|
|
|
|
do_execsql_test 5.1.0 "
|
|
CREATE TABLE t1(a, b, c, $cols, PRIMARY KEY(a, b, c)) WITHOUT ROWID;
|
|
CREATE INDEX i1 ON t1($cols);
|
|
|
|
CREATE TABLE t2(i INTEGER PRIMARY KEY, $cols);
|
|
CREATE INDEX i2 ON t2($cols);
|
|
"
|
|
|
|
do_eqp_test 5.1.1 {
|
|
SELECT * FROM t1 ORDER BY c1, c2;
|
|
} {
|
|
0 0 0 {SCAN TABLE t1 USING COVERING INDEX i1}
|
|
}
|
|
|
|
do_eqp_test 5.1.2 {
|
|
SELECT * FROM t2 ORDER BY c1, c2;
|
|
} {
|
|
0 0 0 {SCAN TABLE t2 USING COVERING INDEX i2}
|
|
}
|
|
|
|
|
|
|
|
finish_test
|