A Smart Pointer Technique for Distributed Spatial Databases

Abstract

We are developing a distributed object oriented spatial database prototype. We are extending the GIDB prototype (developed at NRL for using and querying OVPF databases) to support distribution. GIDB is a Geographical Information System coupled with an object oriented spatial database, which is implemented using the GemStone Object Database. We are currently exploring alternatives to add distribution to the prototype.

We tried GemEnterprise as our distributed OODB, but needed to add a different model of distribution to it. In order to do so, we used a smart pointer technique, taking advantage of the dynamic capabilities of the SmallTalk language.

Also, we did several experiments comparing performance of returning a smart pointer from a remote method, or returning a copy of the remote object. The smart pointer usually is smaller, so the transmission cost is smaller, but future messages have to be done remotely instead of locally.