Added/Updated tests\bugs\core_2115_test.py: Refactored. See notes.

Author: pavel-zotov

tests/bugs/core_2115_test.py

@@ -4,27 +4,67 @@
 ID:          issue-2548
 ISSUE:       2548
 TITLE:       Query plan is missing for the long query
-DESCRIPTION:
+DESCRIPTION: test creates table with one index and generates query like:
+                 select * from ... where
+                     exists(select ...) and
+                     exists(select ...) and
+                     exists(select ...) and
+                     ...
+             -- where number of sub-queries is defined by variable SUBQRY_COUNT
+             Then we open cursor and ask to show execution plan (in traditional form).
+             Plan must have SUBQRY_COUNT lines with the same content: 'PLAN (T1 INDEX (T1_X))'
 JIRA:        CORE-2115
 FBTEST:      bugs.core_2115
+NOTES:
+    [07.09.2023] pzotov
+    1. Refactored because old query did use "IN(...)" predicate with lot of literals.
+       This query became non-actual since IN-algorithm was changed in 
+       https://github.com/FirebirdSQL/firebird/commit/0493422c9f729e27be0112ab60f77e753fabcb5b
+       ("Better processing and optimization if IN <list> predicates (#7707)")
+    2. Although firebird-driver and firebird-qa assumes to be used under FB 3.x+, generated script
+       was also checked on FB 2.0.7.13318 and FB 2.1.7.18553. Both these old versions can NOT produce
+       any output after SUBQRY_COUNT >= 97.
+    3. Upper limit for SUBQRY_COUNT currently still the same: 256. After exceeding of this, we get:
+       "SQLSTATE = 54001 ... -Too many Contexts of Relation/Procedure/Views. Maximum allowed is 256"
 """
 
 import pytest
-from zipfile import Path
 from firebird.qa import *
 
-db = db_factory()
+init_sql = """
+    create sequence g;
+    recreate table t1(
+       x smallint
+    );
+    commit;
+    insert into t1 select mod(gen_id(g,1), 256) from rdb$types,(select 1 i from rdb$types rows 10);
+    commit;
+    create index t1_x on t1(x);
+    commit;
+"""
+db = db_factory(init = init_sql)
 
 act = python_act('db')
 
 @pytest.mark.version('>=3.0')
-def test_1(act: Action):
-    # Read script and expected stdout from zip file
-    datafile = Path(act.files_dir / 'core_2115.zip',
-                    at='tmp_core_2115_queries_with_long_plans.sql')
-    act.script = datafile.read_text()
-    datafile = Path(act.files_dir / 'core_2115.zip',
-                    at='tmp_core_2115_check_txt_of_long_plans.log')
-    act.expected_stdout = datafile.read_text()
-    act.execute()
+def test_1(act: Action, capsys):
+
+    SUBQRY_COUNT = 256
+    test_sql = """
+select 1 as c
+from t1
+where x = 0 and
+    """
+
+
+    test_sql += '\n'.join( ( f'exists(select 1 from t1 where x = {i}) and' for i in range(SUBQRY_COUNT-1) ) )
+    test_sql += '\n1=1'
+
+    with act.db.connect() as con:
+        cur = con.cursor()
+        ps = cur.prepare(test_sql)
+        print(ps.plan)
+
+    expected_stdout = '\n'.join( ('PLAN (T1 INDEX (T1_X))' for i in range(SUBQRY_COUNT)) )
+    #assert '' == capsys.readouterr().out
     assert act.clean_stdout == act.clean_expected_stdout