To determine what software and hardware you need, you must first categorize your planned use of the database manager as one or more of the following:
Each of these environments is described in detail below, including the DB2 Server for VSE functions supported, and options that are either recommended or required for the associated program products.
Batch processing, as shown in Figure 1, is used for submitting jobs to run in a non-interactive mode. A job is submitted using job control (JCL) with or without the VSE/ICCF facilities. The only requirement beyond the base prerequisites is one of the supported programming languages.
Batch facilities are useful for job-preparation tasks like preprocessing and compiling host language programs, or for running applications. Application programs that do not require end-user access can be run in batch. Batch processing places minimal demands on system resources (real storage and processor power).
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Online transaction processing, as shown in Figure 2, requires installation of the online support, and of CICS/VSE, or an equivalent product to support double-byte character set (DBCS) characters and to provide the terminal management and transaction-processing support. Online programs can be written in any of the supported programming languages. You can install ISQL, but its use is limited to data administration functions. Consider this environment for preplanned business applications where end user access to the system is managed through CICS/VSE transactions programmed for specific end user tasks.
For this environment, configure the system as follows:
Figure 2. Online Transaction Processing Configuration
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An application development environment, as shown in Figure 3, involves a large amount of data design, application coding, and testing. Such activities typically involve less SQL activity in the form of data definition, catalog queries, and program preprocessing. Correspondingly there is greater demand for real storage and processor resources than that demanded by application or transaction processing.
Figure 3. Interactive Application Development Configuration
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The configuration requirements are the same as those described for online transaction processing.
The query/report writing environment, as shown in Figure 4, supports dynamic SQL query and report writing by end users. This environment places a relatively high demand on system resources, because user requests must be dynamically interpreted, the number of requests is not limited, and sorting may be very frequent.
Figure 4. Query/Report Writing Configuration
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The configuration requirements are the same as those described for the online transaction processing environment.
Figure 5 depicts a typical configuration with one database, one batch partition user, and a CICS(R) partition with several interactive users.
Figure 5. Basic Components of the RDBMS in VSE
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The database is composed of :
The database manager is the program that provides access to the data in the database. It is loaded into the database partition from the DB2 Server for VSE library.
The application server is the facility that responds to requests for information from and updates to the database. It is composed of the database and the database manager.
The application requester is the facility that transforms a request from an application into a form suitable for communication with an application server.
This section summarizes the program products required or recommended for the DB2 Server for VSE functions and environments available with this release. Unless otherwise stated, the database manager works with all subsequent versions, releases, and modification levels of the products listed in this section as well as with equivalent non-IBM products.
When installing this product on a VSE system, you require an environment provided by VSE/Enterprise Systems Architecture (VSE/ESA) Version 2 Release 3 Modification 1 or later. DB2 Server for VSE requires VSE/VSAM which is included with this operating system.
Table 1 summarizes the components needed for the usage environments,
as well as the languages supported by each environment.
| DB2/VSE Environments | DB2/VSE Components 1 | Supported Languages | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Base | ORA | ISQL | PL/I | COBOL | COBOL II | FOR- TRAN | C | ASM | |||
| Batch | X | X | X | X | X | X | X | ||||
| Online | X | X | X | X | X | X | X | X | |||
| Interactive application development | X | X | X | X | X | X | X | X | X | ||
| Query/Report Writing | X | X | X | ||||||||
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The size of the partition running the database manager is your primary design consideration for determining virtual storage requirements. Virtual storage requirements of other components are less significant as they are smaller or transient in nature.
Several factors contribute to the virtual storage requirements of the partition. The dominant ones are the sizes of the buffer pools (used for directory and data), the number of concurrent users to be supported, the complexity of the SQL requests, and the additional storage required for the optional DRDA support. (The DRDA support makes DB2 Server for VSE data accessible to users equipped with the DRDA remote unit of work application requester function. For more information, see Chapter 14, Using a DRDA Environment.)
The recommended minimum partition size is 5MB, plus 204KB times the maximum number of concurrently active users. However, this is only a guideline; detailed formulas for calculating virtual storage requirements are provided in Appendix A, Processor Storage Requirements.
Hardware requirements include real storage, DASD space, tape, and display terminals.
You need not allocate any real storage for the database manager over and above what is already defined for the partition. However, if more real storage is available, there is less paging, thus improving performance.
The VSE guest sharing facility requires 40 kilobytes of real storage for each database communication link.
DASD space requirements are discussed under the following categories: libraries, database data sets, and starter database. If you use the accounting facility, you can direct its output to DASD or tape. For guidelines on estimating DASD space requirements for the accounting facility, see Chapter 10, Using the Accounting Facility.
Table 2 shows the requirements of the DB2 Server for VSE library
on various devices.
Table 2. DASD Storage Requirements for DB2 Server for VSE Library
| APPROXIMATE SPACE REQUIREMENT: 28,735 LIBRARY BLOCKS | ||
|---|---|---|
| DASD Device Type | Approximate Library Space Required | MSHP History File Space Required |
| 3375 | 93 cylinders | 15 tracks |
| 3380 | 60 cylinders | 15 tracks |
| 3390 | 59 cylinders | 15 tracks |
| 9345 | 69 cylinders | 15 tracks |
| FB-512 | 54,672 blocks | 900 blocks |
Notes:
A database requires a minimum of three VSAM datasets:
The directory and log extents are described in Chapter 2, Planning for Database Generation, and database extents are described in Chapter 7, Managing Database Storage.
The A-type member ARISDBG, which comes with this product, contains IBM-supplied specifications for generating a starter database. This database consists of one directory data set, one log data set, and one user-data dbextent. You can later add more dbextents, up to a logical maximum size of about 4.6 gigabytes, using the information in Adding Dbextents to a Storage Pool.
It is recommended that you generate the starter database at the time of installation, and experiment with it in order to familiarize yourself with the database manager. You may then keep it as your production database. However, as your needs grow, you may find it necessary to transfer its contents to another database, which can be a major undertaking. Thus, once you are familiar with how it works, it is best to discard it and generate your own database by following the guidelines in Chapter 2, "Planning for Database Generation".
The initial physical size of the starter database is predefined and will be about the same on all IBM storage devices. Figure 6 shows the approximate cylinder allocations (or block allocations, in the case of FB-512) on various devices.
Figure 6. Recommended Starter Database DASD Sizes
This starter database must be able to fit in a single dbextent. If you do not have enough DASD, you will not be able to use the IBM-supplied specifications, and will have to generate your own database at the time of installation. If you want to define the equivalent of the starter database on the devices shown in Figure 6, you must define multiple dbextents on multiple volumes.
If you are migrating from a previous release of the database manager, you already have at least one database, so generating the starter database is optional. The advantage of doing so is that you can use it as a test database to verify your installation, but the disadvantages are the work involved and the necessary DASD allocations. Thus to deal with migration needs, the database manager provides allocations for generating a starter database that is large enough to hold the initial database components (for example, HELP text, catalog tables, and FORTRAN packages), but not much else. Figure 6 also shows the data set sizes for a minimum starter database.
The database manager must have a VSAM master catalog and optionally, a VSAM user catalog. Each of the database data sets (the directory, the logs, and the dbextents) must be cataloged in either a user catalog or the master catalog.
One tape drive is required for installation. Once the database manager is running, tape drives are only required for the following activities:
For all of these facilities except archiving, you can use DASD instead of tape.
Also, with the exception of accounting output, the database manager does not require the continuous use of any tape drive: tape mounts are requested when needed. If you are using tape drives, you should have at least two to cover all your needs.
The database manager supports all tape drives that are supported by the operating system.
A variety of display terminals are supported, including the larger screen sizes offered by some models of the 3278 and 3279 (or equivalent) devices. Since CICS is needed to provide terminal support for DB2 Server for VSE online applications, the terminal must be one that is supported by CICS.
You can direct ISQL-printed output to a terminal printer rather than the system printer. To use terminal printers with ISQL, update the CICS tables as described in the DB2 Server for VSE Program Directory manual.
Terminals and workstations that follow the line disciplines represented on VSE/Power remote job entry are also supported by ISQL.
| Note: | To display and print DBCS characters (for example, Japanese HELP text), a DBCS terminal and printer (for example, the IBM 5550 terminal) are required. |
The DBNAME directory is a required directory of all DBNAMEs accessible from the VSE system. It identifies:
The DBNAME directory is contained in A-type source member ARISDIRD. IBM-supplied defaults are provided, but these can be changed. For more information, see Setting Up the DBNAME Directory.
When running on VSE/ESA 2.5, DB2 Server for VSE is key-enabled. For information on setting up the DB2 key, see the DB2 Server for VSE Program Directory.