To access the Memory Summary panel, navigate through Databases > Instance Homepage > Database Homepage, and then choose Memory > Memory summary.
To access the Buffer Pools panel, navigate through Databases > Instance Homepage > Database Homepage, and then choose Memory > Buffer Pools.
All database data is stored in a number of Tablespaces. There are different types of tablespaces, including catalog, regular, large, system-temporary, and user-temporary tablespaces. Tablespaces can be managed by the OS (System-Managed Space — SMS) or the database (Database-Managed Space — DMS). Each tablespace can have one or more containers. Each tablespace has a page size associated with it, which limits the row length and column count of tables that can be placed in the tablespace, meaning that a larger page increases the capacity of the tablespace. The utilization of the page size has an effect on the usage of overall tablespace resources. For example, having a small table with a large page size results in a significant amount of wasted space and inefficient I/O and buffering usage.
The Tablespaces panel shows the top ten tablespaces with the highest percentage of the space usage, along with individual table properties for each individual tablespace. Use this panel to quickly investigate the existing tablespace usage and look for parameters that can indicate potential performance issues.
To access the Tablespaces panel, navigate through Databases > Instance Homepage > Database Homepage, and then choose Storage > Tablespaces.
You can also access the Tablespaces panel for a database from the Databases Dashboard by clicking the icon at the far right of the database name cell and then selecting Tablespaces from the menu that appears.
The Tablespace Details view shows individual tablespace properties and metrics. This dashboard also provides space utilization and free space fragmentation charts that can give you insight in how well the system can perform based on the existing storage resources. For example, a high amount of fragmented disk space can lead to increased performance overhead. You drill down to this view by clicking a tablespace entry on the Tablespaces dashboard or clicking on the tablespace name in the Tablespace Summary section.
A buffer pool is memory that temporarily stores data and index pages from the database. If an application needs to read a data or index page and that page is already in the buffer pool, the application reads the page from the buffer pool, a process that is faster than retrieving the page from disk. Avoiding disk I/O is a critical issue when you are trying to improve database logical and physical read performance.
The Tablespaces Bufferpools Activities panel shows the top tablespaces with the highest percentage of the space usage, and for each tablespace, it displays its buffer pool usage, such as data reads and writes. Use this dashboard to quickly investigate the buffer pool usage for the top tablespace consumers, and to look at the overall buffer pool performance.
To access the Tablespaces Bufferpool Activities panel, navigate through Databases > Instance Homepage > Database Homepage, and then choose Storage > Tablespaces Bufferpool Activities.
The Diagnostic Log panel provides a graphic, color-coded representation of the notification log messages, sorted by their severity level, as detailed below. Informational messages and warnings are displayed here, but do not invoke alarms.
To access the Diagnostic Log panel, navigate through Databases > Instance Homepage > Database Homepage, and then choose Log.
To access the Initialization Parameters panel, navigate through Databases > Instance Homepage > Database Homepage, and then choose Configuration.