Flash in a DBMS: Where and How?

Over the past decade, new solid state storage technologies, with flash being the most mature one, have become increasingly popular. Such technologies store data durably, and can alleviate many handicaps of hard disk drives (HDDs). Nonetheless, they have very different characteristics compared to HDDs, making it challenging to integrate such technologies into data intensive systems, such as database management systems (DBMS), that rely heavily on underlying storage behaviors. In this paper, we ask the question: Where and how will flash be exploited in a DBMS? We describe techniques for making effective use of flash in three contexts: (i) as a log device for transaction processing on memory-resident data, (ii) as the main data store for transaction processing, and (iii) as an update cache for HDD-resident data warehouses.