Vincent J. Carey RDBMS in Bioinformatics: The Bioconductor Experience **************************************************** Bioconductor (http://www.bioconductor.org/) is an open source collection of resources aimed at transparently advancing the theory and practice of bioinformatics, with a focus on expression arrays and the R statistical computing environment. I will sketch the key data structures and data flow processes addressed in Bioconductor thus far. I will review the role played by RDBMS in the development and curation of packaged annotation networks and in the analysis of Serial Analysis of Gene Expression (SAGE) libraries. Non-relational database technologies such as BerkeleyDB and HDF5 have also played a role in tools for archiving and navigating expression array data. At present the role of RDBMS in Bioconductor is less pronounced than had been anticipated. This will change as requirements for query optimization, data structure standardization, and greater volumes of data and metadata emerge.