Added/Updated tests\bugs\gh_7118_test.py: Checked on 3.0.11.33665, 4.0.3.2904, 5.0.0.964

tests/bugs/gh_7118_test.py

@@ -0,0 +1,85 @@
+#coding:utf-8
+
+"""
+ID:          issue-7118
+ISSUE:       https://github.com/FirebirdSQL/firebird/issues/7118
+TITLE:       Chained JOIN .. USING across the same column names may be optimized badly
+NOTES:
+    [01.03.2023] pzotov
+    Checked on 3.0.11.33665, 4.0.3.2904, 5.0.0.964
+"""
+
+import pytest
+from firebird.qa import *
+
+db = db_factory()
+
+test_script = """
+    recreate table t1 (id int primary key, col int);
+    create index t1_col on t1 (col);
+    recreate table t2 (id int primary key, col int);
+    create index t2_col on t2 (col);
+    recreate table t3 (id int primary key, col int);
+    create index t3_col on t3 (col);
+
+    set plan;
+    select *
+    from t1 t1
+      inner join t2 t2 on t1.id = t2.id
+      inner join t3 t3 on t1.id = t3.id
+    where
+      t1.col = 0
+      and t2.col = 0
+      and t3.col = 0;
+    -- PLAN JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY11), T3 INDEX (RDB$PRIMARY12))
+
+    select *
+    from t1 t1
+      inner join t2 t2 on t1.id = t2.id
+      inner join t3 t3 on t2.id = t3.id
+    where
+      t1.col = 0
+      and t2.col = 0
+      and t3.col = 0;
+    -- PLAN JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY11), T3 INDEX (RDB$PRIMARY12))
+
+    select *
+    from t1 t1
+      inner join t2 t2 on t1.id = t2.id
+      inner join t3 t3 on t1.id = t3.id and t2.id = t3.id
+    where
+      t1.col = 0
+      and t2.col = 0
+      and t3.col = 0;
+    -- PLAN JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY11), T3 INDEX (RDB$PRIMARY12))
+
+    select *
+    from t1 t1
+      inner join t2 t2 using (id)
+      inner join t3 t3 using (id)
+    where
+      t1.col = 0
+      and t2.col = 0
+      and t3.col = 0;
+    -- The last query with USING syntax gets a different (usually worse) plan.
+    -- This issue is closely related to #3357, because using (id) is internally
+    -- transformed into coalesce(t1.id, t2.id) = t3.id.
+    -- PLAN HASH (JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY11)), T3 INDEX (T3_COL))
+"""
+
+act = isql_act('db', test_script)
+
+""
+
+expected_stdout = """
+    PLAN JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY2), T3 INDEX (RDB$PRIMARY3))
+    PLAN JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY2), T3 INDEX (RDB$PRIMARY3))
+    PLAN JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY2), T3 INDEX (RDB$PRIMARY3))
+    PLAN JOIN (T1 INDEX (T1_COL), T2 INDEX (RDB$PRIMARY2), T3 INDEX (RDB$PRIMARY3))
+"""
+
+@pytest.mark.version('>=3.0.9')
+def test_1(act: Action):
+    act.expected_stdout = expected_stdout
+    act.execute(combine_output = True)
+    assert act.clean_stdout == act.clean_expected_stdout