Bug #71293 Manual page for P_S.FILE_INSTANCES table does not explain EVENT_NAME values
Submitted: 4 Jan 2014 18:35 Modified: 6 Jan 2014 12:12
Reporter: Valeriy Kravchuk Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Performance Schema Severity:S3 (Non-critical)
Version:5.6 OS:Any
Assigned to: Paul Dubois CPU Architecture:Any
Tags: event_name, file_instances, missing manual, performance_schema

[4 Jan 2014 18:35] Valeriy Kravchuk
Description:
This manual page, http://dev.mysql.com/doc/refman/5.6/en/file-instances-table.html, does not provide enough information about the table to use it efficiently. 

Specifically, it does not list possible values for EVENT_NAME column, even for the most typical MySQL instance with tables using storage engines available by default.

How to repeat:
Check this output:

mysql> select distinct(event_name) from performance_schema.file_instances;
+--------------------------------------+
| event_name                           |
+--------------------------------------+
| wait/io/file/sql/ERRMSG              |
| wait/io/file/mysys/charset           |
| wait/io/file/sql/FRM                 |
| wait/io/file/myisam/kfile            |
| wait/io/file/myisam/dfile            |
| wait/io/file/innodb/innodb_data_file |
| wait/io/file/innodb/innodb_log_file  |
| wait/io/file/mysys/cnf               |
| wait/io/file/sql/pid                 |
| wait/io/file/csv/metadata            |
| wait/io/file/csv/data                |
| wait/io/file/sql/dbopt               |
| wait/io/file/archive/data            |
| wait/io/file/sql/file_parser         |
+--------------------------------------+
14 rows in set (0,00 sec)

and try to find out in the manual what is the meaning of wait/io/file/sql/file_parser event (or when it is created), for example.

Suggested fix:
List all kinds of files MySQL instance may open, with correspondent EVENT_NAME values.
[6 Jan 2014 12:12] Umesh Shastry
Hello Valeriy,

Thank you for the bug report.

Thanks,
Umesh
[21 Jun 2:12] Paul Dubois
Posted by developer:
 
The setup_instruments table now has a DOCUMENTATION column that should say what wait/io/file/% instruments are for. However, all such instruments have an empty DOCUMENTATION column. Changing category to server bug. Devs should modify instrument definitions to define the documentation string.