global_status_diff_clean

NAME

global_status_diff_clean: Status variables difference over time, with spaces where zero diff encountered

TYPE

View

DESCRIPTION

global_status_diff_clean is a visual presentation case for global_status_diff

It presents with same data from global_status_diff, except that when no difference encountered (value unchanged for the sampling duration), the zero value is replaced with empty text.

It is merely a visualization aid, allowing the eye to more easily catch changed values. Automated reads should keep to global_status_diff.

STRUCTURE

mysql> DESC common_schema.global_status_diff_clean;
+------------------------+---------------+------+-----+---------+-------+
| Field                  | Type          | Null | Key | Default | Extra |
+------------------------+---------------+------+-----+---------+-------+
| variable_name          | varchar(64)   | YES  |     | NULL    |       |
| variable_value_0       | longtext      | YES  |     | NULL    |       |
| variable_value_1       | varchar(1024) | YES  |     | NULL    |       |
| variable_value_diff    | varbinary(23) | YES  |     | NULL    |       |
| variable_value_psec    | varbinary(23) | YES  |     | NULL    |       |
| variable_value_pminute | varbinary(23) | YES  |     | NULL    |       |
+------------------------+---------------+------+-----+---------+-------+

SYNOPSIS

The structure of this view is identical to that of global_status_diff, except:

  • variable_value_diff: difference between the two samples, or empty text when difference is zero
  • variable_value_psec: average change in value per second of execution, or empty text when difference is zero
  • variable_value_pminute: estimated (via extrapolation) average change in value per minute of execution, or empty text when difference is zero

EXAMPLES

Get status difference for various InnoDB write metrics:

mysql> SELECT * FROM common_schema.global_status_diff_clean WHERE variable_name LIKE 'innodb_%write%';
+-----------------------------------+------------------+------------------+---------------------+---------------------+------------------------+
| variable_name                     | variable_value_0 | variable_value_1 | variable_value_diff | variable_value_psec | variable_value_pminute |
+-----------------------------------+------------------+------------------+---------------------+---------------------+------------------------+
| innodb_buffer_pool_write_requests | 1000933916       | 1000934526       | 610                 | 61                  | 3660                   |
| innodb_data_pending_writes        | 0                | 0                |                     |                     |                        |
| innodb_data_writes                | 100388839        | 100389001        | 162                 | 16.2                | 972                    |
| innodb_dblwr_writes               | 603346           | 603346           |                     |                     |                        |
| innodb_log_write_requests         | 338954473        | 338954531        | 58                  | 5.8                 | 348                    |
| innodb_log_writes                 | 69347559         | 69347618         | 59                  | 5.9                 | 354                    |
| innodb_os_log_pending_writes      | 0                | 0                |                     |                     |                        |
+-----------------------------------+------------------+------------------+---------------------+---------------------+------------------------+

ENVIRONMENT

MySQL 5.1 or newer

SEE ALSO

global_status_diff, global_status_diff_nonzero

AUTHOR

Shlomi Noach
 
common_schema documentation