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Oracle® Database Appliance Getting Started Guide
Release 2.9 for Linux x86-64

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C Database Sizing for Oracle Database Appliance

This appendix provides information about database sizing and other configuration options. This appendix contains the following topics:

Using Templates for Consolidation with Instance Caging

You are able to consolidate multiple databases using Oracle Database Appliance. Oracle Database provides a method for managing CPU allocations on a multi-CPU server running multiple database instances. This method is called instance caging. Instance caging and Oracle Database Resource Manager (the Resource Manager) support the desired levels of service across multiple instances. Consolidation can minimize idle resources, maximize efficiency, and lower costs.

Oracle Database Appliance templates are pre-tuned for the size of each database instance workload and designed by default to run on a specific number of cores. Caging assures that each database workload is restricted to the set of cores allocated by the template, enabling multiple databases to run concurrently with no performance degradation, up to the capacity of Oracle Database Appliance. You may select database template sizes larger than your current needs to provide for planned growth, which you accommodate later by adjusting System Global Area (SGA) and Program Global Area (PGA) sizes as well as the number of cores.

Note:

Oracle strongly recommends that you use the Oracle Database Appliance templates, because they implement best practices and are configured specifically for Oracle Database Appliance.

You may use either Oracle Appliance Manager or Database Configuration Assistant (DBCA) to create databases on Oracle Database Appliance. The templates are available with both utilities.

Tip:

The Oracle Appliance Manager Configurator refers to the database sizing templates as classes of databases.

Use tables 4, 4, and 4in this section to help select the best templates for your databases. When using these tables remember:

  • The CPU_COUNT values are not core count values. If you use this table to determine Oracle Database Appliance licensing requirements, then divide the CPU_COUNT value by two to find the minimum number of cores you will need to license. For a Very Small database, which only needs one core, your minimum license would depend on your configuration as follows:

    • License two cores on Oracle Database Appliance X3-2 or Oracle Database Appliance X4-2 Virtualized Platforms

    • License four cores on Oracle Database Appliance X3-2 or Oracle Database Appliance X4-2 bare metal installations

    • License two cores on Oracle Database Appliance, either bare metal or Virtualized Platform.

  • The information in the tables assume that you are creating disk backups. With external tape backups, database size can be up to 3.2 TB.

  • I/O per second (IOPS) values are derived from an 8K random read/write response time of 5 milliseconds to service an OLTP I/O request. The rates are not based on the number of CPUs and assume that the system is running at capacity. For example, on as Oracle Database Appliance X4-2 system with no expansion storage shelf and 12 small databases all running, each database would experience about 275 IOPS. With only one database running on the system, IOPS should be 3,300. Similarly, on an Oracle Database Appliance system with one large and six very small databases all running, the very small databases would experience about 300 IOPS each and the large database would experience about 2,000 IOPS.

  • Throughput, in MB/second (MBPS). is based on a1 MB sequential read/write for a data warehousing system. As with IOPS, the MBPS is a measure of throughput when the system is at capacity. With just a single small database running, the MBPS would be the maximum available on the system for a large database.

  • The log file size assumes four redo log groups for each instance with a log switch every 15 minutes when the system is running at full capacity.

Refer to the information that is appropriate to your hardware:

  • Use Table C-1 if your database is on Oracle Database Appliance X4-2.

  • Use Table C-2 if your database is on Oracle Database Appliance X3-2.

  • Use Table C-3 if your database is on Oracle Database Appliance.

Table C-1 Oracle Database Appliance X4-2 Database Template Sizes

System Component Very Very Small Very Small Small Medium Large Extra Large Extra Extra Large Extra Extra Extra Large

CPU_COUNT (for each instance)

2

2

4

8

12

24

32

48

SGA (GB)

2

4

8

16

24

48

64

96

PGA (GB)

1

2

4

8

12

24

32

48

Processes

200

200

400

800

1200

2400

3200

4800

Log file size (GB)

1

1

1

2

4

4

4

4

Number of databases using this template that you can deploy

24

24

12

6

4

2

1

1

I/O per second (IOPS) with single storage shelf

137

137

275

550

825

1650

3300

3300

Throughput (MB/second) with single storage shelf

145

145

292

583

875

1750

3500

3500

I/O per second (IOPS) with storage shelf plus storage expansion shelf

275

275

550

1100

1650

3300

6600

6600

Throughput (MB/second) with storage shelf plus storage expansion shelf

230

230

458

917

1375

2750

5500

5500

Log generation (MB/second)

6.83

6.83

6.83

13.65

27.30

27.30

27.30

27.30


Table C-2 Oracle Database Appliance X3-2 Database Template Sizes

System Component Very Very Small Very Small Small Medium Large Extra Large Extra Extra Large

CPU_COUNT (for each instance)

2

2

4

8

12

24

32

SGA (MB)

2048

4096

8192

16384

24576

49152

65536

PGA (MB)

1024

2048

4096

8192

12288

24576

32768

Processes

200

200

400

800

1200

2400

3200

Log file size (GB)

1

1

1

2

4

4

4

Number of databases using this template that you can deploy

24

16

8

4

2

1

1

I/O per second (IOPS) with single storage shelf

206

206

412

825

1650

3300

3300

Throughput (MB/second) with single storage shelf

146

219

438

875

1750

3500

3500

I/O per second (IOPS) with storage shelf plus storage expansion shelf

275

413

825

1650

3300

6600

6600

Throughput (MB/second) with storage shelf plus storage expansion shelf

230

344

688

1375

2750

5500

5500

Log generation (MB/second)

6.83

6.83

6.83

13.65

27.30

27.30

27.30


Table C-3 Oracle Database Appliance Database Template Sizes

System Component Very Very Small Very Small Small Medium Large Extra Large

CPU_COUNT (for each instance)

2

2

4

8

12

24

SGA (MB)

2048

4096

8192

16384

24576

49152

PGA (MB)

1024

2048

4096

8192

12288

24576

Processes

200

200

400

800

1200

2400

Log file size (GB)

1

1

1

2

4

4

Number of databases using this template that you can deploy

24

12

6

3

2

1

I/O per second (IOPS)

167

333

666

1333

2000

4000

Throughput (MB/second)

125

250

500

1000

1500

3000

Log generation (MB/second)

6.83

6.83

6.83

13.65

27.30

27.30


For each database, select the template that best fits your expected workload on the hardware that you are using. Or select a template that fits the growth that you expect for your databases.

Note:

Disk hardware capacity is measured using 1 KB = 1,000 bytes whereas software storage requirements are based on 1 KB = 1,024 bytes. This means that a disk with a rated capacity of 900 GB has only about 860 GB of space for software storage.

Enabling Instance Caging for Oracle Database Appliance

By default, instance caging is not enabled on Oracle Database Appliance. To enable instance caging, enable Oracle Database Resource Manager by setting the RESOURCE_MANAGER_PLAN initialization parameter for each database on Oracle Database Appliance, so that you allocate core resources among databases. The Resource Manager parameter specifies the top plan, identifying the plan to be used for the current instance. If no plan is specified with this parameter, then the Resource Manager is not enabled.

On Oracle Database Appliance, instance caging allocation of core resources is enabled in accordance with the Oracle Database Appliance database template size that you select for each database. The CPU_COUNT initialization parameter is set in the template. Use the CPU_COUNT setting that matches the size of each database to consolidate, and follow the standard instructions for configuring instance caging.

See Also:

Oracle Database Administrator's Guide for more information about enabling and configuring instance caging

How to Choose a Database Class

Resources in Oracle Database Appliance are finite. When deciding which database class to use, determine how your applications use these finite resources:

  • Storage—Database size

  • Workload—CPU, Memory, and storage performance (IOPS/MBPS)

Caution:

Only use the database sizing examples that are provided with this document as a guideline. The actual performance that you achieve can depend on other factors. Test your system's performance after deployment to ensure that the performance meets your needs.

Database Classes for Oracle Real Application Clusters (Oracle RAC)

Use the numbers in Table C-3 or Table C-2 as guidelines to choose the most appropriate database class for Oracle RAC deployments. Remember that only cores are licensed components. Other resources, such as memory and storage, are available, regardless of how many cores are active. After you have deployed a database using one of the pre-tuned Oracle Database Appliance templates, you may use remaining resources on Oracle Database Appliance for additional deployments.

Caution:

Actual performance may depend on other factors. Test your system's performance after deployment to ensure that the performance optimal.

Example 1: Choosing a Database Size Option

The sizing guidelines provided in Table C-3 show that a single Oracle Database Appliance can support one Extra Large database that uses twelve cores (for each node), or twelve Very Small databases that each use one core (for each node). The guidelines also show that a single Oracle Database Appliance can support one Extra Large database capable of 3000 IOPS, or six Small databases each of which are capable of 600 IOPS.

Assume that you have the following three databases to consolidate on Oracle Database Appliance:

  • The first database, D1, is 800 GB with 300 IOPS.

  • The second database, D2, is 200 GB with 500 IOPS.

  • The third database, D3, is 75 GB with 600 IOPS.

Based on the minimum IOPS and size requirements, you may deploy the three databases as follows:

  • D1 as Large

  • D2 as Small

  • D3 as Small

To support the three databases, license ten cores for each node (20 cores for Oracle Database Appliance).

Example 2: Choosing a Database Size Option

Assume that you have two databases to deploy on a new Oracle Database Appliance.

  • The first database, DB1, is 2 TB with 3000 IOPS.

  • The second database, DB2, is 1 TB with 3000 IOPS.

Because you plan to send your backups to tape, this deployment is possible because the combined size of the two databases is 3 TB, and Oracle Database Appliance can support up to 3.2 TB.

Next consider the I/O requirements. DB1 and DB2 each generate 3000 IOPS, which means that Oracle Database Appliance must support a total of 6000 IOPS. However, 6000 IOPS is greater than Oracle Database Appliance can support while maintaining a five millisecond response time. An Extra Large database only supports up to 3000 IOPS.

The Large size can support two databases, each generating 2000 IOPS. Based on database size and IOPS, you may deploy only one of your databases. In this case, to obtain 6000 IOPS, license six cores for each node and deploy the database with a Large configuration.