Bug #78123 reading from innodb_trx returning warnings when non-utf8 chars in trx_query.

• Submitted: 18 Aug 2015 11:09
• Reporter: Shane Bester (Platinum Quality Contributor)
• Status: Verified
• Category: MySQL Server: Information schema
• Severity: S3 (Non-critical)
• Version: 5.6.26
• OS: Any
• CPU Architecture: Any

[18 Aug 2015 11:09] Shane Bester

Description:
The issue is that trx_query is not expected to contain only valid utf8 characters.  It might be legitimate binary data for a query.

This leads to unnecessary warnings,  even when we are NOT querying trx_query:

mysql> \W
Show warnings enabled.
mysql> select trx_id from information_schema.innodb_trx;
+---------+
| trx_id  |
+---------+
| 8206952 |
| 8206951 |
| 8206950 |
| 8206949 |
| 8206948 |
| 8206947 |
| 8206946 |
| 8206945 |
| 8206944 |
+---------+
9 rows in set, 1 warning (0.00 sec)

Warning (Code 1366): Incorrect string value: '\xC1D\xFF\x12\xD3\x1A...' for column 'trx_query' at row 1
mysql> select version();
+---------------------------------------+
| version()                             |
+---------------------------------------+
| 5.6.26-enterprise-commercial-advanced |
+---------------------------------------+
1 row in set (0.00 sec)

How to repeat:
run any workload that contains non-utf8 characters in the query.  In another thread:

select trx_id from information_schema.innodb_trx;
show warnings;

Suggested fix:
Previous fix for https://bugs.mysql.com/bug.php?id=55397 does not seem complete.
I think trx_query should be BLOB or VARBINARY data type.