In spite of SQL standardization by SQL-89 and SQL-92, there are still considerable differences in the extent of the SQL language between the SQL systems available on the market. For the portability of an application program, essential parts (e.g., the most important return messages to be dealt with by the application program) have not yet been sufficiently taken into account by the standardizations currently available.
To provide more options to our users, ADABAS supports the most important SQL dialects by selecting an SQLMODE:
- ADABAS
- ANSI
- ORACLE
The SQLMODE determines the extent of the SQL language, the structure and significance of SQLCA and SQLDA, data types supported, as well as the numbering of the most important return messages. The aim is to be able to take over existing application systems which were written for another SQL system without modifying them by selecting the suitable SQLMODE. The SQLMODE can be set for each session.
ADABAS
This is the most attractive SQLMODE because it is the most powerful. Facilities exceeding the standard and performance spectrum of other SQL systems are only available in this SQLMODE. For the user, this means maximum productivity combined with optimal performance.
ANSI
For users who want to achieve the highest possible portability of their applications, the restriction to the entry level of SQL-92 can be selected with this SQLMODE. ADABAS will then only accept SQL statements which conform to the ANSI standard. The fulfillment of the ANSI standard by ADABAS is assured by the United States National Institute of Standards and Technology (NIST) test suite against which ADABAS D was certified in October 1994.
This option is particularly interesting for software companies which have to make their products available on various relational database systems and for whom the standardized facilities suffice.
ORACLE
With this SQLMODE, ADABAS understands ORACLE-specific SQL extensions; e.g., for built-in functions or dynamic SQL. The point of reference for ORACLE compatibility is ORACLE7.
This option is interesting for software companies that have developed a program on the basis of ORACLE and want to make it available on ADABAS. The porting of the application in this case requires only that the application sources be precompiled.
For users who want to introduce a two-company policy for database suppliers in their organization, this is an interesting perspective.