SET HIPERFOCUS = {ON|OFF}

where:

ON

Activates HiperFOCUS. This is the default.

OFF

Deactivates HiperFOCUS.

? SET HIPERFOCUS

If HiperFOCUS is installed, the command displays the message HIPERFOCUS ON or HIPERFOCUS OFF.

The following parameters can be set only in the FOCPARM ERRORS file. On z/OS, this file is member FOCPARM of the data set allocated to ddname ERRORS. On CMS, it is the file named FOCPARM ERRORS.

The following parameters can be set only in the z/OS console or during IBI Subsytem installation. See your FOCUS installation guide for information.

The ? HBUDGET query shows the Hiperspace limits specified and actual utilization statistics, including: limits set at the system, server, user and file levels; the number of busy pages; the number of hiperextents allowed; and the ddnames and sizes of files allocated in hiperspace or spilled to disk.

>? HBUDGET
Total system     limit is not set
Total server     limit is not set
Total hiperspace limit is not set
Single file size limit is   524288 pages
Total amount of busy pages is  616 pages
Number of extents is set to    127
 
DDname :Reserved :Hiperspace : Spilled :Spill DDn

When FOCUS allocates a temporary file in a hiperspace, it first verifies that the file's primary extent does not exceed your site's hiperspace limit. If the primary extent is too large, the file is automatically allocated to disk instead.

To determine if the allocation for a temporary file is within your site's hiperspace limit, you can calculate the file's size, in 4096-byte pages, using a formula. A hiperspace can be up to two gigabytes. However, your site may have specified smaller limits in one of the following ways:

• System exit. In the z/OS IEFUSI site-defined system exit.
• Installation. When installing HiperFOCUS.

pages=(primary_extent * 12) + ((secondary_extent * operations) * 12)

pages=(primary_extent * 12 * 15) + ((secondary_extent * operations) * 12 * 15)

DYNAM ALLOC FILE TEMPDSN SP 5 5 CYL UNIT NOHIPER

DYNAM ALLOC FILE TEMPDSN SP 5 5 CYL UNIT SYSDA HIPER OFF

On z/OS, you can determine where a temporary file is allocated by issuing a query command. The query command returns information including the following:

• DEVICE, which has the value HIPERFILE or DISK depending upon where the file was allocated.
• DSNAME, which has the value FOCUS.HIPERFILE.NOT.OPENED if the file was allocated in a hiperspace but has not yet been opened; otherwise, its value is the data set name. If the first qualifier of the data set name is HIPER, this file was created in a hiperspace.

? {MVS|TSO} DDNAME ddname

In some situations you may wish to copy a file from a hiperspace to disk. For example, if you create a series of HOLD files, you may need to save one of them to a permanent data set.

You can copy a file from a hiperspace to disk using the DYNAM COPY command, as described in the Overview and Operating Environments manual.

FOCUS can write pages to disk after exhausting the expanded storage allocation with the HiperFOCUS Spill to Disk feature. This feature, which eliminates error messages associated with inadequate storage, is activated by setting the TRACKIO parameter to ON.

To check on how many pages are in expanded storage and how many were spilled to disk, issue the ? HBUDGET query command described in How to Query HiperBUDGET Limits and Usage.

Note: To preserve performance gains achieved through HiperFOCUS, we recommend that you allow only 10% of the pages to spill to disk. If you find that over 10% are on disk, ask your system administrator to allocate additional space for expanded storage.

Issue the following command at the FOCUS command prompt:

CMS CP Q SPACES

Hiperspaces can be up to two gigabytes. However, your site may have specified a smaller limit in the following ways:

• XCONFIG. By including the XCONFIG ADDRSPACE statement in the z/VM directory entry for a user's virtual machine.
• Installation. By setting a limit when HiperFOCUS is installed.

With HiperFOCUS activated, the default cache buffer size is 256 pages (that is, one megabyte). This differs from standard cache, where the default is 0 pages (that is, cache is turned off). You can change the default for HiperFOCUS cache when HiperFOCUS is installed. You can also control HiperCache in the following ways:

• Activation. You can turn HiperCache on and off using the CACHE parameter, described in How to Set Cache.

  If you turn cache on (SET CACHE = n), but HiperFOCUS is turned off (SET HIPERFOCUS = OFF), the buffer is allocated as standard cache.

• Status. You can check how many cache reads were done by issuing the ? STAT command.
• Size. You can change the size of the HiperCache buffer using the CACHE parameter, described in How to Set Cache.

  When resizing cache (either HiperCache or standard cache), you may wish to wait until all applications have completed. Changing size while cache is active reallocates the cache buffer, discarding all data currently stored there.

SET CACHE = {0|n}

A rule is a sequence of rule statements. A rule statement can be:

• A condition. Allows a user to access HiperFOCUS. The condition is represented as an expression that is evaluated as true or false. A condition can be of two types: ACCEPT (sufficient conditions) and REQUIRE (necessary, but not sufficient conditions).
• A temporary field definition. Subsequent rule statements can refer to the temporary field.

A rule must have at least one ACCEPT statement, and can contain an unlimited number of ACCEPT, REQUIRE, and temporary field statements.

REQUIRE = expression;

ACCEPT = expression;

tempfield[/format] = expression;

ACCEPT = USERID IS 'FOCSYS';
REQUIRE = (HOUROFDAY LE '09') OR (HOUROFDAY GE '17');

The HiperRule facility evaluates rule statements sequentially, beginning with the first statement:

• It terminates the evaluation process if it encounters a true ACCEPT statement or a false REQUIRE statement.
• All expressions following a true ACCEPT statement or a false REQUIRE statement are not evaluated.

The HiperRule facility permits a user to access HiperFOCUS if all of a rule's evaluated REQUIRE statements are true and at least one of its ACCEPT statements is true. A statement is true when its expression is true.

In some situations, you may find it helpful to create a rule statement that is always true or always false. Because the value 1 represents true, and the value 0 represents false, the following statement is true under all conditions:

ACCEPT = 1;

The following statement is false under all conditions:

REQUIRE = 0;

ACCEPT  = USERID IS 'HFUSER1';
REQUIRE = TODAYSDATE GE '20010425';
REQUIRE = TODAYSDATE LE '20010525';
ACCEPT  = USERID IS 'PGM030';
ACCEPT  = USERID IS 'PGM040';

The way in which you store a rule depends upon your operating system:

• In z/OS, create the rule as member HIPERULE of the ERRORS partitioned data set.
• In CMS, create the rule as file HIPERULE ERRORS. Only one file with this name may exist on the FOCUS production disk; otherwise, the Resource Governor is disabled.