<p>I've been working with RDBMs since the mid 1980s, over many different platforms from IBM Mainframes to embedded systems. Although I predominantly describe myself as a developer I've performed a DBA role, both formally and informally, on many occassions.</p>
<p>I developed a considerable expertese in management, design, and optimisation, and I'm particularly good at designing systems for efficient access and optimising queries. For example one recent client has a PostGres database containing large volumes of geographical data (biggest table size would be over 500 million records). A crucuial feature of the project was a complicated query which provided the user with a geographical analysis of their data: when the client first came to me this query was taking over five minutes to run in the worst cases, but by a series of optimizations I reduced this down to generally under 2 seconds, and 5 at most, and hence made the product commercially viable.</p>
<p>I mainly use MySQL, MSSQL and PostGres, currently about equally and I'll happily consult on any of these. I also have specialist experience of the Geographical extensions for these, particularly on PostGres (PostGIS). I've also used SQLLite extensively, and historically many other systems such as Oracle, DB2 and Firebird, so happy to answer more general SQL questions on those if you can't find a specialist for those databases online.</p>
