# H2
Activate H2 as storage, set storage provider to **H2** In-Memory Databases by default in the distribution package.
Please read `Database URL Overview` in [H2 official document](http://www.h2database.com/html/features.html).
You can set the target to H2 in **Embedded**, **Server** and **Mixed** modes.

Setting fragment example
```yaml
storage:
  selector: ${SW_STORAGE:h2}
  h2:
    driver: org.h2.jdbcx.JdbcDataSource
    url: jdbc:h2:mem:skywalking-oap-db
    user: sa
    maxSizeOfBatchSql: ${SW_STORAGE_MAX_SIZE_OF_BATCH_SQL:100}
    asyncBatchPersistentPoolSize: ${SW_STORAGE_ASYNC_BATCH_PERSISTENT_POOL_SIZE:1}
```