Calculating the Logical Record Length

You must supply the logical record length to the Create operation (14). The logical record length is the number of bytes of fixed-length data in the file. To obtain this value, calculate how many bytes of data you need to store in the fixed-length portion of each record.

For example, the following table shows how the data bytes in the example Employees file are added together to obtain a logical record length:


Field	Length (in Bytes)
Last Name	25
First Name	25
Middle Initial	1
Employee ID	4
Phone Number	13
Pay Rate	4
LOGICAL RECORD LENGTH	72

In calculating the logical record length, you do not count variable-length data, because variable-length information is stored apart from the fixed-length record in the file (on variable pages).

The maximum logical record length depends on the file format as defined in Table 16.

Table 16

Maximum Logical Record Length by File Format

Pervasive PSQL Version

Example

9.5

page size minus 10 minus 2 (record overhead)

8.x through 9.x

page size minus 8 minus 2 (record overhead)

6.x through 7.x

page size minus 6 minus 2 (record overhead)

Pre-6.x

page size minus 6 minus 2 (record overhead)

Note: The record overhead in these examples is for a fixed-length record (not a variable record) without record compression.