general query log

The design of a data warehouse differs from relational design. Data warehouses are often designed according to the concept of the star schema.

When building a data warehouse, you usually put the cart before the horse:

Das Design eines Data Warehouses unterscheidet sich vom relationalen Design. Data Warehouses designt man oft nach dem Konzept des Star Schemas.

Üblicherweise zäumt man beim Bau eines Data Warehouses das Pferd von hinten auf:

The MariaDB Connection ID exists since long ago. So why bother about the Connection ID? Because it is interesting and you can do some interesting things with the Connection ID like tracking statements in your connections and find where they come from your application code.

The MariaDB Connection ID is a strictly monotonic increasing number starting with 1 at server restart:

The General Query Log in MariaDB is a Log (file or table) that logs every statement sent from the Application to the MariaDB Database Server from the Connect Command to the Quit Command. A simple example you can find here:

Unsere Präsentation von der CeBit 2015: MySQL Performance Tuning für Entwickler kann jetzt heruntergeladen werden.

Inhalt: Datenbank Performance, Profiling, General Query Log, des Admins Bazooka, Slow Query Log, Query Analyzer, Query Execution Plan, EXPLAIN, Indexieren, ...

... The question is, does enabling the general query log affects the MySQL performance ?
Also, it is possible to record the output of this log into either file or table in the mysql database (mysql.general_log), what is the performance impact of each one?

Let's do some simple benchmark for those scenarios to measure the actual impact on the mysql performance.

Früher, lange, lange ist's her, konnte man den folgenden Trick verwenden um MySQL Queries in der Applikation zu taggen:

SELECT /* My Application Tag */ * FROM test;

Im Slow Query Log und im General Query Log ist das SQL Query dann wie folgt erschienen:

# Time: 111020 22:03:33
# User@Host: root[root] @ localhost []  Id:  1335
# Query_time: 17.873938  Lock_time: 0.007952 Rows_sent: 12048576  Rows_examined: 12048576
use test;
SET timestamp=1319141013;
SELECT /* My Application Tag */ * FROM test;

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