We introduce a prewrite operation before a write operation is performed on design databases, a database that consists of objects as engineering designs. A prewrite operation does not actually make a design but it only makes available the model of the design that the transaction will produce in future. Once the prewrite design by a transaction is announced, the transaction executes a pre-commit operation. After the pre-commit, read operations can access the prewrite design even before the pre-committed transaction has finally made the design and committed. Therefore, our algorithm increases the potential concurrency as compared to the algorithms that permit only read and write operations on the design objects. In our algorithm, a user explicitly makes available a prewrite model of the design to be finally produced. Similarly, a read transaction also mentions whether it wants to read a prewrite version or the final version of the design. Locking protocols using two phase locking are given to control concurrent operations

Meeting Name

1997 International Conference on Information, Communications and Signal Processing, 1997


Computer Science

Keywords and Phrases

Database Management Systems; Database Theory; Design Database Concurrency; Design Engineering; Engineering Designs; Locking Protocols; Multiprocessing Programs; Pre-Commit Operation; Prewrite Design; Prewrite Model; Prewrite Operation; Protocols; Read Operations; Read Transaction; User Defined Prewrites; Write Operation

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 1997 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 1997