Description File Examples
The sample description files shown in this section describe a data file. This data file has a page size of 512 bytes and 2 keys. The fixed-length portion of the record is 98 bytes long. The file allows variable-length records but does not use blank truncation.
The file uses record compression, allows for Variable-tail Allocation Tables (VATs), and has the free space threshold set to 20 percent. The MicroKernel Database Engine preallocates 100 pages, or 51,200 bytes, when it creates the file. The file has two keys: Key 0 and Key 1. Key 0 is a segmented key with two segments.
In Figure 44, both keys use the same ACS file name (upper.alt). In Figure 45, both keys use the same country ID (-1) and code page ID (-1). In Figure 46, Key 0 and Key 1 use different ACS file names (lower.alt and upper.alt, respectively). In Figure 47, the file has no keys except the system-defined key used for logging.
Figure 44 Sample Description File Using Alternate Collating Sequence File Name
Figure 45 Sample Description File Using Alternate Collating Sequence ID
Figure 46 Sample Description File Using Alternate Collating Sequence File Name on a Key Segment
Figure 47 Sample Description File Using System-Defined Key for Logging