Remote computing gets a boost with replication technology. (Inside SQLWindows)(Column)(Tutorial)

If all the database applications on the planet ran on one computer--using one database--and all users were always connected to it, data replication technology would have no reason to exist. The unlikelihood of the above scenario, given current software and hardware limitations (not to mention social, political, economic, and religious concerns), means data replication technology will stick around--at least for now. Until software vendors make distributed computing worth the time, data replication is your next best option.

This issue's column provides an underlying look at why replication technology is a hot topic, and gives a sneak preview into the way Gupta Corporation is implementing it--including the benefits for remote users who want to replicate data to a network from a laptop.

Distributed transactions

Replication technology gets its origins from relational databases and client-server computing, which gained momentum in the early- to mid-1980s. At that time, developers began discussing the differences between remote requests, remote transactions, distributed requests, and distributed transactions.

A remote request refers to a single SQL statement, typically a SELECT, which is sent to a single database server for processing. A remote transaction consists of multiple SQL statements, representing one logical transaction, that is being processed by a single server. Distributed requests and transactions are the same as remote requests and transactions with respect to the distinction between single and multiple SQL statements. However, they're different where the server is …