This paper presents a low-overhead caching method called FaCE that utilizes flash memory as an extension to a DRAM buffer for a recoverable database. FaCE caches data pages in flash memory on exit from the RAM buffer. By basing its caching decision solely on the RAM buffer replacement, the flash cache is capable of sustaining high hit rates without incurring excessive run-time overheads for monitoring access patterns, identifying hot and cold data items, and migrating them between flash memory and disk drives. We have implemented FaCE and its optimization strategies within the PostgreSQL open-source database server and demonstrated that FaCE achieves a significant improvement in the transaction throughput.