If a table is on the rhs of a LEFT JOIN, include only terms from the joins ON(...) clause in the cursor-hint passed via OP_CursorHint.

FossilOrigin-Name: 2a2346b04235c6d0b7a8e64c92ee31018285c29f
2016-06-17 14:33:32 +00:00
parent 3480bfdae9
commit b324cf756e
4 changed files with 142 additions and 12 deletions
@@ -0,0 +1,101 @@
+# 2016 June 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.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library. The
+# focus is on testing that cursor-hints are correct for queries
+# involving LEFT JOIN.
+#
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set ::testprefix cursorhint2
+
+ifcapable !cursorhints {
+  finish_test
+  return
+}
+
+proc extract_hints {sql} {
+
+  db eval "SELECT tbl_name, rootpage FROM sqlite_master where rootpage" {
+    set lookup($rootpage) $tbl_name
+  }
+
+  set ret [list]
+  db eval "EXPLAIN $sql" a {
+    switch -- $a(opcode) {
+      OpenRead {
+        set csr($a(p1)) $lookup($a(p2))
+      }
+      CursorHint { 
+        lappend ret $csr($a(p1)) $a(p4) 
+      }
+    }
+  }
+
+  set ret
+}
+
+proc do_extract_hints_test {tn sql ret} {
+  uplevel [list do_test $tn [list extract_hints $sql] [list {*}$ret]]
+}
+
+do_execsql_test 1.0 {
+  PRAGMA automatic_index = 0;
+  CREATE TABLE t1(a, b);
+  CREATE TABLE t2(c, d);
+  CREATE TABLE t3(e, f);
+}
+
+do_extract_hints_test $tn.1.1 {
+  SELECT * FROM t1 WHERE a=1;
+} {
+  t1 EQ(c0,1)
+}
+
+do_extract_hints_test $tn.1.2 {
+  SELECT * FROM t1 CROSS JOIN t2 ON (a=c) WHERE d IS NULL;
+} {
+  t2 {AND(ISNULL(c1),EQ(r[1],c0))}
+}
+
+do_extract_hints_test $tn.1.3 {
+  SELECT * FROM t1 LEFT JOIN t2 ON (a=c) WHERE d IS NULL;
+} {
+  t2 {EQ(r[2],c0)}
+}
+
+do_extract_hints_test $tn.1.4 {
+  SELECT * FROM t1 LEFT JOIN t2 ON (a=c AND a=10) WHERE d IS NULL;
+} {
+  t2 {AND(EQ(r[2],c0),EQ(r[3],10))}
+}
+
+do_extract_hints_test $tn.1.5 {
+  SELECT * FROM t1 CROSS JOIN t2 ON (a=c AND a=10) WHERE d IS NULL;
+} {
+  t1 EQ(c0,10) t2 {AND(ISNULL(c1),EQ(r[3],c0))}
+}
+
+do_extract_hints_test $tn.1.6 {
+  SELECT * FROM t1 LEFT JOIN t2 ON (a=c) LEFT JOIN t3 ON (d=f);
+} {
+  t2 {EQ(r[2],c0)} t3 {EQ(r[6],c1)}
+}
+
+do_extract_hints_test $tn.1.6 {
+  SELECT * FROM t1 LEFT JOIN t2 ON (a=c AND d=e) LEFT JOIN t3 ON (d=f);
+} {
+  t2 {EQ(r[2],c0)} t3 {EQ(r[6],c1)}
+}
+
+finish_test
+