This paper presents the design of a read-optimized relational DBMS that contrasts sharply with most current systems, which are write-optimized. Among the many differences in its design are: storage of data by column rather than by row, careful coding and packing of objects into storage including main memory during query processing, storing an overlapping collection of columnoriented projections, rather than the current fare of tables and indexes, a non-traditional implementation of transactions which includes high availability and snapshot isolation for read-only transactions, and the extensive use of bitmap indexes to complement B-tree structures. We present preliminary performance data on a subset of TPC-H and show that the system we are building, C-Store, is substantially faster than popular commercial products. Hence, the architecture looks very encouraging. EMP1 (name, age) EMP2 (dept, age, DEPT.floor) EMP3 (name, salary) DEPT1(dname, floor) Example 1: Possible projections for EMP and DEPT Name Age Dept Salary Bob 25 Math 10K Bill 27 EECS 50K Jill 24 Biology 80K