MariaDB [(none)]> set histogram_size=10;
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Query OK, 0 rows affected (0.00 sec)
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MariaDB [(none)]> set histogram_type='double_prec_hb';
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Query OK, 0 rows affected (0.00 sec)
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MariaDB [(none)]> show variables like 'histogram%';
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+----------------+----------------+
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| Variable_name | Value |
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+----------------+----------------+
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| histogram_size | 10 |
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| histogram_type | DOUBLE_PREC_HB |
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+----------------+----------------+
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2 rows in set (0.00 sec)
|
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MariaDB [(none)]> use test;
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Database changed
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MariaDB [test]> create table t21 ( a int);
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Query OK, 0 rows affected (0.01 sec)
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MariaDB [test]> insert into t21 values (1),(2),(3),(4),(5);
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Query OK, 5 rows affected (0.01 sec)
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Records: 5 Duplicates: 0 Warnings: 0
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|
MariaDB [test]> analyze table t21 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.t21 | analyze | status | OK |
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+----------+---------+----------+----------+
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1 row in set (0.00 sec)
|
|
MariaDB [test]> select *, hex(histogram),length(histogram) from mysql.column_stats where db_name='test' and table_name='t21'\G
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*************************** 1. row ***************************
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db_name: test
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table_name: t21
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column_name: a
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min_value: 1
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max_value: 5
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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: SINGLE_PREC_HB
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histogram: �?�����
|
hex(histogram): 0000FF3FFF7FFFBFFFFF
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length(histogram): 10
|
1 row in set (0.00 sec)
|