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firebird-qa/tests/bugs/gh_8113_test.py

72 lines
2.3 KiB
Python

#coding:utf-8
"""
ID: issue-8113
ISSUE: https://github.com/FirebirdSQL/firebird/issues/8113
TITLE: UNION ALL optimization with constant false condition
DESCRIPTION:
Test uses script based on example from ticket.
Number of UNIONed parts is defined via UNION_MEMBERS_CNT variable.
We compare number of natural reads with threshold = 1 (see MAX_ALLOWED_NAT_READS).
NOTES:
[18.11.2024] pzotov
Confirmed excessive reads on 6.0.0.520.
Checked on 6.0.0.532 -- all OK.
"""
import pytest
from firebird.qa import *
#########################
MAX_ALLOWED_NAT_READS = 1
UNION_MEMBERS_CNT = 254
#########################
view_ddl = f'recreate view v_test as ' + '\nunion all '.join( [f'select {i} as x from test' for i in range(UNION_MEMBERS_CNT)] ) + '\n;'
init_sql = f"""
recreate table test(id int);
insert into test(id) values(0);
commit;
{view_ddl}
"""
db = db_factory(init = init_sql)
act = python_act('db')
#-----------------------------------------------------------
@pytest.mark.version('>=6.0')
def test_1(act: Action, capsys):
msg_prefix = 'Number of natural reads:'
expected_txt = 'EXPECTED'
nat_reads = {}
with act.db.connect() as con:
cur = con.cursor()
cur.execute("select rdb$relation_id from rdb$relations where rdb$relation_name = upper('test')")
src_relation_id = cur.fetchone()[0]
nat_reads[src_relation_id] = 0
for x_table in con.info.get_table_access_stats():
if x_table.table_id == src_relation_id:
nat_reads[src_relation_id] = -x_table.sequential
cur.execute(f"select /* trace_tag */ x from v_test where x = {UNION_MEMBERS_CNT-1}")
data = cur.fetchall()
for x_table in con.info.get_table_access_stats():
if x_table.table_id == src_relation_id:
nat_reads[src_relation_id] += x_table.sequential
if nat_reads[src_relation_id] <= MAX_ALLOWED_NAT_READS:
print(f'{msg_prefix} {expected_txt}')
else:
print(f'{msg_prefix} UNEXPECTED: {nat_reads[src_relation_id]} - greater than threshold = {MAX_ALLOWED_NAT_READS}.')
act.expected_stdout = f"""
{msg_prefix} {expected_txt}
"""
act.stdout = capsys.readouterr().out
assert act.clean_stdout == act.clean_expected_stdout