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Description File Elements
Description file elements must appear in a particular order. Table A-1 lists the description file elements in the appropriate order. For each element, the table specifies the required format and the range of acceptable values.
- An asterisk (*) indicates that the element is optional.
- A pound sign (#) indicates that it is not applicable in the current MicroKernel version but is retained for backward compatibility with previous MicroKernel versions.
- A percent sign (%) indicates that the element is applicable only to the current MicroKernel version.
Table A-1 Summary of Description File Elements Element Keyword and Format Range Comments File Specification Information Comment Block* /*. . . . . . . . . . . . */ 5,120 bytes None. Record Length record=nnnn 4 - 4,088 None. Variable-Length Records variable=<y|n> N/A Not applicable to key-only files. Reserved Duplicate Pointer* dupkey=<nnn> 0-119 Applicable only to files for which you plan to add linked-duplicatable keys. Blank Truncation* truncate=<y|n> N/A Not applicable for files that use data compression. Data Compression* compress=<y|n> N/A Not applicable to key-only files. Key Count key=nnn 0 -119 Specify 0 to create a data-only file. Page Size page=nnnn 512- 4,096 Must be a multiple of 512. Page Preallocation* allocation=nnnnn 1- 65,535 None. Replace Existing File*# replace=<y|n> N/A None. Include Data* data=<y|n> N/A Specify n to create a key-only file. Cannot create a key-only file that both allows duplicates and uses a system-defined key. Free Space Threshold* fthreshold=<5|10|20|30> N/A Applicable only for files that have variable-length records. The default is 5. Variable-Tail Allocation Tables (VATs) huge=<y|n> #
vats=<y|n> N/A Applicable only for files that have variable-length records. Balanced Index* balance=<y|n> N/A None. Use Key Number * usekeynum=<y|n> N/A Used with the Key Number element. 1Use System Data*% sysdataonrecord=
<n|loggable> N/A If no element specified, MicroKernel configuration is used. If creating a key-only file, MicroKernel configuration is used and this element is ignored. Also, you cannot create a key-only file that both allows duplicates and uses a system-defined key. Key Specification Information Key Number * keynum=nnn 0-118 Must be unique to the file, specified in ascending order, and valid for the file's Page Size. Applicable only when creating a file. Key Position position=nnnn 1- 4,088 Cannot exceed the Record Length. Key Length length=nnn key type limit Cannot exceed the limit dictated by the Key Type. For binary keys, the key length must be an even number. The total of the Key Position and Key Length cannot exceed the file's Record Length. Duplicate Key Values duplicates=<y|n> N/A Cannot create a key-only file that allows duplicates and uses a system-defined key. Modifiable Key Values modifiable=<y|n> N/A None. Key Type type=
validMKDEKeyType N/A Can enter the entire word (as in float) or just the first three letters (as in flo). Descending Sort Order* descending=<y|n> N/A None. Alternate Collating Sequence alternate=<y|n> N/A Applicable only for case sensitive STRING, LSTRING, WSTRING, WZSTRING, or ZSTRING keys. When creating an additional index for an existing file, if you want the index to use an ACS other than the first one in the data file, use withcaseinsensitive=y
. Case-Insensitive Key* caseinsensitive=<y|n> N/A Applicable only for STRING, LSTRING, or ZSTRING keys that do not use an ACS. Repeating Duplicates* repeatdup=<y|n> N/A If creating a key-only file, use repeating duplicates. If using this element, you must use duplicates=y. Null Segments* nullkey=<allsegs | n | anyseg |> N/A None. Null Key Value value=nn 1-byte hex Used with the Null Segments element. Segmented Key segment=<y|n> N/A None. Alternate Collating Sequence File Name/ID name=sequenceFile or countryid=nnn and codepageid=nnn
isr=table name (%) valid path or values valid to operating system or
-1 Used with the Alternate Collating Sequence element.
1When the MicroKernel adds a system key, the resulting records may be too large to fit in the file's existing page size. In such cases, the MicroKernel automatically increases the file's page size to the next accommodating size.
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