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MariaDB [test]> create table t1 (a int);
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Query OK, 0 rows affected (0.00 sec)
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MariaDB [test]> set @a:=-1;
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Query OK, 0 rows affected (0.00 sec)
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MariaDB [test]> insert into t1 select @a:=@a+1 from information_schema.session_variables;
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Query OK, 404 rows affected (0.03 sec)
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Records: 404 Duplicates: 0 Warnings: 0
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MariaDB [test]> set histogram_size=10;
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Query OK, 0 rows affected (0.00 sec)
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MariaDB [test]> set histogram_type='single_prec_hb';
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Query OK, 0 rows affected (0.00 sec)
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MariaDB [test]> analyze table t1 persistent for all;
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+---------+---------+----------+----------+
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| Table | Op | Msg_type | Msg_text |
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+---------+---------+----------+----------+
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| test.t1 | analyze | status | OK |
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+---------+---------+----------+----------+
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1 row in set (0.01 sec)
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MariaDB [test]> select *, hex(histogram) from mysql.column_stats\G
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*************************** 1. row ***************************
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db_name: test
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table_name: t1
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column_name: a
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min_value: 0
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max_value: 403
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nulls_ratio: 0.0000
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avg_length: 4.0000
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avg_frequency: 1.0000
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hist_size: 10
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hist_type:
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histogram: �.E\s����
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hex(histogram): 162E455C738BA2B9D0E8
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1 row in set (0.00 sec)
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|
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MariaDB [test]> set histogram_size=20;
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Query OK, 0 rows affected (0.00 sec)
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MariaDB [test]> analyze table t1 persistent for all;
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+---------+---------+----------+-----------------------------+
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| Table | Op | Msg_type | Msg_text |
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+---------+---------+----------+-----------------------------+
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| test.t1 | analyze | status | Table is already up to date |
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+---------+---------+----------+-----------------------------+
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1 row in set (0.01 sec)
|
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MariaDB [test]> select *, hex(histogram) from mysql.column_stats\G
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*************************** 1. row ***************************
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db_name: test
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table_name: t1
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column_name: a
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min_value: 0
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max_value: 403
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nulls_ratio: 0.0000
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avg_length: 4.0000
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avg_frequency: 1.0000
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hist_size: 20
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hist_type:
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histogram:
|
�$0<HT`my���������
|
hex(histogram): 0C1824303C4854606D7985919EAAB6C2CEDAE6F2
|
1 row in set (0.00 sec)
|