Bug #89793 INFORMATION_SCHEMA.STATISTICS field type change
Submitted: 23 Feb 2018 17:27 Modified: 20 Mar 2018 18:12
Reporter: Mark Guinness Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Information schema Severity:S3 (Non-critical)
Version:8.0 OS:Any
Assigned to: CPU Architecture:Any
Tags: schema

[23 Feb 2018 17:27] Mark Guinness 
Description:
INFORMATION_SCHEMA tables are now implemented as views on data dictionary tables (https://dev.mysql.com/doc/refman/8.0/en/data-dictionary-information-schema.html).

NON_UNIQUE column was BIGINT but is now VARCHAR which is a change from earlier versions of MySQL.

How to repeat:
Run following in both 5.7 and 8.0 to see differences (https://www.db-fiddle.com/f/fYuGmJXVjbRtNkKXmVnbYy/0).

SHOW COLUMNS 
FROM `INFORMATION_SCHEMA`.`STATISTICS`
WHERE Field = 'NON_UNIQUE'
[23 Feb 2018 22:23] MySQL Verification Team 
Thank you for the bug report.
[20 Mar 2018 18:12] Paul DuBois 
Posted by developer:
 
Fixed in 8.0.11.

The NON_UNIQUE column in the INFORMATION_SCHEMA.STATISTICS table had
type BIGINT prior to MySQL 8.0, but became VARCHAR in MySQL 8.0 with
the introduction of the data dictionary. The NON_UNIQUE column now
has an integer type again (INT because the column need not be as
large as BIGINT).