A key item cannot be a group item or a field item containing a group of Boolean items.

When specifying the section boundaries for a random XE data set, the Enterprise Database Server automatically adds one additional section to store any records whose key values are higher than the boundary for the last section specified (or lower than the boundary for the last section specified if the key is descending).

When specifying the section boundaries for an XE direct data set, the Enterprise Database Server does not add an additional section. The key value specified for the last section indicates the highest value that is intended to be stored in the data set. A limit error can occur at run time if the real key value exceeds this highest value. This is true unless a large enough file size has been specified for the data set using AREAS, AREASIZE, and BLOCKSIZE if AREASIZE is given in blocks. However, the Enterprise Database Server does not enforce this limit.

For direct data sets, the Access can specify a group item. However, the section bounds specification must be specified using the subitems of the group key. It is recommended that the specification for the last section include specifications for all subitems of a group key.

There is always a last section that contains all values outside the last user-specified range.

The following example includes specifications for all subitems of a group key:

D DIRECT DATA SET
   (G GROUP (
             G1  NUMBER(2);
             G2  NUMBER(4);
            );
   INFO          ALPHA(300);
   )EXTENDED=TRUE;
A ACCESS TO D KEY IS G

                SECTIONS (G1 = 50;
                          G1 = 75, G2 = 500
                         );

Ascending Keys

Using ascending keys, the first key value represents the upper boundary for the first section. If the first key value is the lowest value specified, the system assigns records to sections according to the principles listed in the following table.

The section key values must be specified in ascending key value order. The following example assumes DS is a random data set and K1 is an integer:

A ACCESS TO DS KEY IS K1
     SECTIONS (K1 = 99; % 1st section (#1), <=99
              K1 = 199; % 2nd section (#2), 100-199
              K1 = 299; % 3rd section (#3), 200-299
              K3 = 399; % 4th section (#4), 300-399
             );%K1 > 399 go into a 5th section (#5)

Descending Keys

Using descending keys, the first key value represents the lower boundary for the first section. If the first key value is the highest key value specified, the system assigns records to sections according to the principles listed in the following table.

The section key value must be specified in descending key value order. The following example assumes DS is a random data set and K1 is an integer:

A ACCESS TO DS KEY IS K1
   SECTIONS (K1 = 400; % 1st section (#1), >=400
             K1 = 300; % 2nd section (#2), 300 - 399
             K1 = 200; % 3rd section (#3), 200 - 299
             K1 = 100; % 4th section (#4), 100 - 199
            );%K1< 100 go into a 5th section (#5)

Multiple Key Items

If a set contains multiple keys items, you can specify values for the additional key items. The characteristics of multiple key items are as follows:

For example, suppose that DS is a random data set and has Access A with keys K1, K2, K3, and K4. The following two examples are of a key specification for Access A. The first example is valid; the second example is invalid.

Valid Example

A ACCESS (K1,K2,K3,K4) 
    SECTIONS (K1=10, K2=050, K3=300, K4=30;             % 1st section
              K1=10, K2=100, K3=200, K4=100             % 2nd section
              K1=10, K2=100, K3=100, % K4=anything      % 3rd section
              K1=20, K2=100, K3=100, K4=200;            % 4th section
              K1=30; %K1=21-30, K2, K3, &K4 = anything  % 5th section
             );% K1>30 and K2, K3, & K4 = anything      % last section

Invalid Example

A ACCESS (K1,K2,K3,K4)
    SECTIONS (K2=100, K1=10, K3=100, K4=1000 % Keys out of order
              K1=100,        K3=200, K4=2002 % Key skipped
              K1=5                           % Key value for ascending
             )                               % Key not ascending

Alpha Key Value

Field Key Value

Numeric Key Value

The following table illustrates numeric and real key values.