Measures reported by MariaEvtStmtTest
The Performance Schema is a feature for monitoring the database server performance and it is implemented as a storage engine on the Maria Database server. The storage engine contains a database called performance_schema, which in turn consists of a number of tables that can be queried with regular SQL statements, returning specific performance information. Whenever there is a dip in the performance of the Maria Database server, it is necessary for the administrators to check the performance schema tables for any discrepancies. Administrators can use the MariaEvtStmtTest test to perform such a check on the performance schema tables.
This test monitors the performance schema tables of the target Maria Database server and reports the number of digest statements executing on the database server. This test also throws light on the SQL statements that are running on the performance schema tables, the statements waiting for locks and the rows affected and examined. Using this test, administrators can also figure out the FLUSH commands executed on the tables as well as the temporary tables.
Outputs of the test : One set of results for the Maria database server being monitored.
| Measurement |
Description |
Measurement Unit |
Interpretation |
| Digest_statement_count |
Indicates the number of digest statements executing on the database server. |
Number |
The Performance Schema digest is a hashed, normalized form of a statement with the specific data values removed. It allows statistics to be gathered for similar kinds of statements. |
| Lock_waiting_Statements |
Indicates the number of statements that were waiting for a lock on the database server. |
Number |
The detailed diagnosis of this measure lists the Thread ID, Event ID, name of the event, the start time, end time, the duration of the event, the lock time of the event and the SQL statement that created the event. |
| Rows_affected |
Indicates the number of rows that were affected by the statements on the database server. |
Number |
|
| Rows_sent |
Indicates the number of rows sent by the statements on the database server. |
Number |
|
| Rowsamined |
Indicates the number of rows that were read during the statement execution. |
Number |
|
| Statement_errors |
Indicates the rate at which FLUSH commands were executed. |
Number |
|
| Statements_running |
Indicates the number of statements running on the database server. |
Number |
The detailed diagnosis of this measure lists the Thread ID, Event ID, name of the event, the start time, end time, the duration of the event, the lock time of the event and the SQL statement that created the event. |
| Statements_waited |
Indicates the number of statements that were waiting on the database server for execution. |
Number |
|
| Statements_warning |
Indicates the number of statements that were waiting on the database server for execution. |
Number |
|
| Temporary_disk_tables |
Indicates the number of implicit temporary tables that were created on the disk, while executing statements during the last measurement period. |
Number |
If the value of this measure is high, consider increasing the ‘tmp_table_size’ configuration setting for the server. |
| Temporary_tables |
Indicates the number of implicit temporary tables that were created in the memory created while executing statements during the last measurement period. |
Number |
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