A "Bit" Larger Database

Michael A. Kappler
Daylight CIS



THORTM database size has become an issue because Daylight users have reached the 2GB file size limit. This presentation will feature an overview of the database scheme, the reason for the current capacity limitation, and the way we are increasing the limit to 16GB.


What are we doing?

Why are we doing it?

How are we doing it?

Database Scheme

32-bit Addressing

Each entry in the primary data file, called a data record, contains three 4-byte unsigned integers, called a data header, plus the data itself.

Quantized 32-bit Addressing

64-bit Addressing

What do we get?

The pros and cons of various methods for increasing the database size limit are summarized below:

Daylight Chemical Information Systems, Inc.