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Enhance the query planner so that it is able to use indexed expressions

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to help fulfill an ORDER BY clause.

FossilOrigin-Name: 668fc1ebaf426f9eed3ed7865e41f1023dafebfb
This commit is contained in:
drh
2015-09-24 18:47:59 +00:00
parent 76226dd28d
commit dae26fe518
4 changed files with 63 additions and 13 deletions
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test/indexexpr1.test
+37
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@@ -88,6 +88,23 @@ do_execsql_test indexexpr1-160eqp {
WHERE substr(a,27,3)=='ord' AND d>=29;
} {/USING INDEX t1a2/}
# ORDER BY using an indexed expression
#
do_execsql_test indexexpr1-170 {
CREATE INDEX t1alen ON t1(length(a));
SELECT length(a) FROM t1 ORDER BY length(a);
} {20 25 27 29 38 52}
do_execsql_test indexexpr1-170eqp {
EXPLAIN QUERY PLAN
SELECT length(a) FROM t1 ORDER BY length(a);
} {/SCAN TABLE t1 USING INDEX t1alen/}
do_execsql_test indexexpr1-171 {
SELECT length(a) FROM t1 ORDER BY length(a) DESC;
} {52 38 29 27 25 20}
do_execsql_test indexexpr1-171eqp {
EXPLAIN QUERY PLAN
SELECT length(a) FROM t1 ORDER BY length(a) DESC;
} {/SCAN TABLE t1 USING INDEX t1alen/}
do_execsql_test indexexpr1-200 {
DROP TABLE t1;
@@ -255,4 +272,24 @@ do_execsql_test indexexpr1-710 {
ORDER BY +a, +x;
} {1 1 | 2 2 |}
# Collating sequences on indexes of expressions
#
do_execsql_test indexexpr1-800 {
DROP TABLE IF EXISTS t8;
CREATE TABLE t8(a INTEGER PRIMARY KEY, b TEXT);
CREATE UNIQUE INDEX t8bx ON t8(substr(b,2,4) COLLATE nocase);
INSERT INTO t8(a,b) VALUES(1,'Alice'),(2,'Bartholemew'),(3,'Cynthia');
SELECT * FROM t8 WHERE substr(b,2,4)='ARTH' COLLATE nocase;
} {2 Bartholemew}
do_catchsql_test indexexpr1-810 {
INSERT INTO t8(a,b) VALUES(4,'BARTHMERE');
} {1 {UNIQUE constraint failed: index 't8bx'}}
do_catchsql_test indexexpr1-820 {
DROP INDEX t8bx;
CREATE UNIQUE INDEX t8bx ON t8(substr(b,2,4) COLLATE rtrim);
INSERT INTO t8(a,b) VALUES(4,'BARTHMERE');
} {0 {}}
finish_test