Viewing and Modifying Table Properties

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In PCC, it is very easy to view the properties of a table. You can view and modify table properties as needed.

To view the properties of an existing table within a database

Click on the Tables Namespace node under the database whose table you wish to view.

Right-click on the desired table in the table list in the Control Center's right pane.

Select Properties in the shortcut menu. The properties dialog box appears.

Figure 3-21 Table Properties Window

The Table Properties dialog box presents the following information:

Table 3-4 Existing Table Properties
Statistic Name	Description
Table Name	Shows the name of the table as it appears in the database schema.
Table Location	Shows the physical location of the data file associated with the table.
Dictionary Path	Displays where the database's DDF files are located.
File Version	Shows the earliest Btrieve engine version that can read the file format.
Record Length	Shows the length of the data file's records.
Page Size	Shows the page size (in bytes) of the data file. The page size determines the maximum number of index segments that can be defined in a table.
Number of Records	Shows the number of records currently contained in the data file.
Number of Indexes	Shows the number of indexes defined for the table.
Number of Duplicate Pointers	Shows the number of linked duplicate indexes that can be added.
Number of Unused Pages	Shows the number of pre-allocated pages available. If pre-allocation is enabled, the MicroKernel pre-allocates a specified number of pages when it creates the data file. Pre-allocation guarantees that disk space for the data file is available when the MicroKernel needs it.
Variable Records	Shows whether the data file contains variable-length records.
Variable Record Blank Truncation	Shows whether blank truncation is enabled. If it is, the MicroKernel truncates the blanks in variable-length records. Blank truncation is applicable only if the Variable Records statistic is Yes and Data Compression is set to No.
Data Compression	Shows whether data compression is enabled. If it is, the MicroKernel compresses each record it inserts into the data file.
Index Balancing	Shows whether balanced indexing is enabled.
Free Space Threshold	Shows a percentage (5%, 10%, 20% or 30%) if the data file has a free space threshold. The MicroKernel stores the variable-length portions of records on their own pages (called variable pages), separate from the fixed-length portions (which are stored on data pages). The MicroKernel uses the threshold to determine whether to add data to an existing variable page or to create a new one. A higher free space threshold reduces fragmentation of variable-length records across several pages but uses more disk space.
Use Alternate Collating Sequence	Shows whether the table uses an alternate collating sequence for sorting.
System Data Key	Shows whether the data file has system data keys enabled.

Occasionally, a table requires modifications to its list of columns or indexes. The Table Information Manager provides a mechanism through which such changes can be made. See the Table Designer .