How to find all tables whose integer columns have reached max values? - mysql

Question

My primary key is an integer.
I get the error #1062 - Duplicate entry '4294967295' for key 'PRIMARY' on next insert.
Reason: Obviously maximum value is reached.
Is there any way i can find all tables whose integer columns have reached max values or close to reaching max values to avoid such errors

Answer 1

Query:
SELECT
id, IF(max(id)<4294967295, 'true', 'false') as insert_flag
FROM Table
Note: I have checked in above query, whether max id's value is less
then Int Range (4294967295). Query returns true and false in
insert_flag column. You can check this in your code before insertion.

Answer 2

If you were talking about id as some kind of AUTO_INCREMENT field, then you can get this information for all tables with show table status (please use help show table status for more details).
e.g.
mysql> show table status \G
*************************** 1. row ***************************
Name: test_table
Engine: InnoDB
Version: 10
Row_format: Compact
Rows: 0
Avg_row_length: 0
Data_length: 16384
Max_data_length: 0
Index_length: 65536
Data_free: 0
Auto_increment: 2
Create_time: 2014-11-07 13:17:16
Update_time: NULL
Check_time: NULL
Collation: latin1_swedish_ci
Checksum: NULL
Create_options:
Comment:
1 row in set (0.00 sec)

Answer 3

Here's a way to check all the auto-increment columns to see how close they are to their maximum:
SELECT c.TABLE_SCHEMA, c.TABLE_NAME, c.COLUMN_NAME,
(#max_auto_increment_size := CASE
WHEN c.COLUMN_TYPE like 'tinyint% unsigned' THEN 255
WHEN c.COLUMN_TYPE like 'tinyint%' THEN 127
WHEN c.COLUMN_TYPE like 'smallint% unsigned' THEN 65535
WHEN c.COLUMN_TYPE like 'smallint%' THEN 32767
WHEN c.COLUMN_TYPE like 'mediumint% unsigned' THEN 16777215
WHEN c.COLUMN_TYPE like 'mediumint%' THEN 8388607
WHEN c.COLUMN_TYPE like 'int% unsigned' THEN 4294967295
WHEN c.COLUMN_TYPE like 'int%' THEN 2147483647
WHEN c.COLUMN_TYPE like 'bigint% unsigned' THEN 18446744073709551615
WHEN c.COLUMN_TYPE like 'bigint%' THEN 9223372036854775807
ELSE 127
END) AS MAX_AUTO_INCREMENT_SIZE,
ROUND(#max_auto_increment_size - t.AUTO_INCREMENT) AS Headroom,
(CASE
WHEN ROUND(#max_auto_increment_size - t.AUTO_INCREMENT) < 1000 THEN 'CRITICAL'
WHEN ROUND(#max_auto_increment_size - t.AUTO_INCREMENT) < 10000 THEN 'LOW'
ELSE 'OK'
END) AS Remark
FROM information_schema.columns c
JOIN tables t ON (t.TABLE_SCHEMA = c.TABLE_SCHEMA AND t.TABLE_NAME = c.TABLE_NAME)
WHERE c.TABLE_SCHEMA NOT IN('information_schema','mysql','performance_schema')
AND c.EXTRA = 'auto_increment'
ORDER BY c.TABLE_SCHEMA, c.TABLE_NAME, c.COLUMN_NAME;