Overview

There are a number of calls available to use the Texis engine directly, without using SQL. Typical applications might be writing data loaders or dumpers, which do not need to perform queries.

Access is provided directly to the data in the tables. The API is broken out into a number of areas. There are certain advantages and disadvantages that occur using this form of access.

The primary advantage is that you are linked directly into the Texis library. This means that there is no communication method between a client and server, so there is less overhead. Another result of being linked directly into the library is that you are in complete control of the access methods to the data.

This can also be considered a disadvantage as there is no use of indices, or any optimizations done to the query. Another point to consider is that in general any program that has been written that is linked with the Texis library for direct access must be executed on the machine that holds the database. This is because there is no communications layer, and the concurrency control on some systems does not work on a networked file.

All of these functions have declarations in the header "dbquery.h". This header in turn depends on <stdio.h> and <sys/types.h>, so the top of a program including these calls should include the following lines.

#include <stdio.h>
#include <sys/types.h>
#include "dbquery.h"

The calls available are broken into a number of layers.

1. Opening, creating and closing the data dictionary.

2. Opening, creating and closing tables.

3. Reading and writing rows from the table.

Within each layer the calls available are as follows.

• Data Dictionary functions
• Table functions
• Row and Field functions