From 08119c361d1181b3e8f1abb429236e488a664753 Mon Sep 17 00:00:00 2001 From: Hans-Christoph Steiner Date: Tue, 13 Aug 2013 15:42:54 -0400 Subject: Imported Upstream version 2.2.1 --- test/coveridxscan.test | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 test/coveridxscan.test (limited to 'test/coveridxscan.test') diff --git a/test/coveridxscan.test b/test/coveridxscan.test new file mode 100644 index 0000000..7b3c0b0 --- /dev/null +++ b/test/coveridxscan.test @@ -0,0 +1,93 @@ +# 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} + + +finish_test -- cgit v1.2.3