## Kernel Variant

Kernel variants are different variants of the kernel of the database system. They differ in terms of which logs and runtime checks the database system performs during operation.

When the database is started, restarted, transferred to the ADMIN operational state, or transferred to the ONLINE operational state, you can specify explicitly which kernel variant you want the database instance to use.

You can choose from the following kernel variants:

Kernel Variant | Properties
fast | System default value Fastest kernel variant, with minimum logging and runtime checks.
slow | Variant of the kernel with extensive logging and runtime checks

Do not use the slow kernel variant during production operation of the database. The additional logging and runtime checks make this kernel variant much slower than the fast variant, so it should be used by support only.

See also:

Database Manager CLI, db_speed