Bulk Loading into an OODB: A Performance Study

Abstract

Object-oriented database (OODB) users bring with them large quantities of legacy data (megabytes and even gigabIn addition, scientific OODB users continually generate new data. All this data must be loaded into the OODB. Every relational database system has a load utility , but most OODBs do not. The process of loading data into an OODB is complicated by inter-object references, or relationships, in the data. These relationships are expressed in the OODB as object identifiers, which are not known at the time the load data is generated; they may contain cycles; and there may be implicit system-maintained inverse relationships that must also be stored. W e introduce seven algorithms for loading data into an OODB that examine different techniques for dealing with circular and inverse relationships. W e present a performance study based on both an analytic model and an implementation of all seven algorithms on top of the Shore object repository . Our study demonstrates that it is ortant to choose a load algorithm carefully; in some cases the best algorithm achieved an improvement of one to two orders of magnitude over the naive algorithm