Details
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Bug
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Status: Stalled (View Workflow)
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Minor
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Resolution: Unresolved
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10.3(EOL), 10.4(EOL), 10.5, 10.6, 10.7(EOL), 10.8(EOL), 10.9(EOL)
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None
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Linux, e.g. Ubuntu
Description
I set the config "query_cache_size=1355776" and "query_cache_type=1" in the config file in order to use Query_cache. However, for the same "Select *" operation, the Query_cache failed to identify them and stores the redundant queries, after I change the option "time_zone" on the fly. It is not reasonable because the "Selected" table/rows are not time type or date type;
time_zone should not affect the query result.
Similar situations for "default_week_format" and "lc_time_names". Maybe Query_cacher should have a smart identification for redundant queries. It would be more efficient for Query_cache to identify them accurately.
I put the test case and result followed.
Test:
set time_zone = SYSTEM;
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reset query cache;
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flush status;
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create database if not exists mysqltest;
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create table mysqltest.t1 (i int not null);
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insert into mysqltest.t1 (i) values (1);
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show status like "Qcache_queries_in_cache";
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select * from mysqltest.t1 order by i;
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show status like "Qcache_queries_in_cache";
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set time_zone = "+9:00";
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select * from mysqltest.t1 order by i;
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show status like "Qcache_queries_in_cache";
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select * from mysqltest.t1 order by i;
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show status like "Qcache_queries_in_cache";
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Result:
set time_zone = SYSTEM;
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reset query cache;
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flush status;
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create database if not exists mysqltest;
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create table mysqltest.t1 (i int not null);
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insert into mysqltest.t1 (i) values (1);
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show status like "Qcache_queries_in_cache";
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Variable_name Value
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Qcache_queries_in_cache 0
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select * from mysqltest.t1 order by i;
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i
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1
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show status like "Qcache_queries_in_cache";
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Variable_name Value
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Qcache_queries_in_cache 1
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set time_zone = "+9:00";
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select * from mysqltest.t1 order by i;
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i
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1
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show status like "Qcache_queries_in_cache";
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Variable_name Value
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Qcache_queries_in_cache 2
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select * from mysqltest.t1 order by i;
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i
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1
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show status like "Qcache_queries_in_cache";
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Variable_name Value
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Qcache_queries_in_cache 2
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Suggested fix:
time_zone should not affect the query result, which are not time type of date type.