mirror of
https://github.com/FirebirdSQL/firebird-qa.git
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114 lines
3.4 KiB
Python
114 lines
3.4 KiB
Python
#coding:utf-8
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"""
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ID: issue-4254
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ISSUE: 4254
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TITLE: Improve SIMILAR TO performance
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DESCRIPTION:
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Confirmed normal work on WI-T4.0.0.1598. Moreover, SIMILAR TO is about 5x faster than LIKE comparison in this test.
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CAUTION.
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This test must be run only on 4.0+, despite that its 'Fix version' = 3.0 Alpha 1.
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Performance of SIMILAR TO statement is extremely poor in comparison with LIKE operator:
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COUNT through the table of 102 records requires 27 seconds vs 16 ms (checked on WI-V6.3.6.33246).
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JIRA: CORE-3919
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FBTEST: bugs.core_3919
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"""
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import pytest
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from firebird.qa import *
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db = db_factory(from_backup='core3919.fbk')
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test_script = """
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set heading off;
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set list on;
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set term ^;
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execute block returns(
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ratio_of_time varchar(255)
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) as
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declare i int;
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declare j int;
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declare t0 timestamp;
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declare t1 timestamp;
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declare elap_ms_using_like int;
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declare elap_ms_using_similar_to int;
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declare s varchar(32761);
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declare ratio_similar_vs_like numeric(15,4);
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declare MAX_RATIO numeric(15,4) = 2;
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-- ^
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-- #############
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-- MAX THRESHOLD
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-- #############
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declare n_count int = 100; -- do not set it to values less than 10: duration should not be zero!
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begin
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t0 = cast('now' as timestamp);
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select count(*) as like_count, sum(char_length(b)) as like_sum_len
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from test t, (select 1 i from rdb$types rows (:n_count) ) n
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where
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t.b like '%a%' or
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t.b like '%b%' or
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t.b like '%c%' or
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t.b like '%d%' or
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t.b like '%e%' or
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t.b like '%f%' or
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t.b like '%g%' or
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t.b like '%h%' or
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t.b like '%i%' or
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t.b like '%j%' or
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t.b like '%k%' or
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t.b like '%l%' or
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t.b like '%m%' or
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t.b like '%n%' or
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t.b like '%o%' or
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t.b like '%p%' or
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t.b like '%q%' or
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t.b like '%r%' or
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t.b like '%s%' or
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t.b like '%t%' or
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t.b like '%u%' or
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t.b like '%v%' or
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t.b like '%w%' or
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t.b like '%x%' or
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t.b like '%y%' or
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t.b like '%z%'
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into i,j
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;
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t1 = cast('now' as timestamp);
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elap_ms_using_like = datediff(millisecond from t0 to t1);
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t0 = cast('now' as timestamp);
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select count(*) as similar_to_count, sum(char_length(b)) as similar_to_sum_len
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from test t, (select 1 i from rdb$types rows (:n_count) ) n
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where t.b similar to '%[a-z]%'
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into i,j
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;
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t1 = cast('now' as timestamp);
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elap_ms_using_similar_to = datediff(millisecond from t0 to t1);
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ratio_similar_vs_like = 1.0000 * elap_ms_using_similar_to / elap_ms_using_like;
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ratio_of_time = iif( ratio_similar_vs_like < MAX_RATIO
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,'acceptable'
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,'TOO LONG: '|| ratio_similar_vs_like ||' times. This is more than max threshold = ' || MAX_RATIO || ' times'
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)
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;
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suspend;
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end
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^
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"""
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act = isql_act('db', test_script)
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expected_stdout = """
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RATIO_OF_TIME acceptable
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"""
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@pytest.mark.version('>=4.0')
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def test_1(act: Action):
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act.expected_stdout = expected_stdout
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act.execute()
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assert act.clean_stdout == act.clean_expected_stdout
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