My IT career began back in 1997 with Experian UK Ltd working with mainframe languages such as PL/1, SAS, JCL etc. and the IBM DB2 database. A few years later I had a brief stint as a VB6 programmer before moving into Oracle in 2001.
Picking up a large Oracle 9i project migrating Mainframe batch into Oracle with an online application interacting to define the batch options, successful implementation was rolled out and the business entered serious Oracle use. Future developments mitigated the mainframe at a time when Barclays entered the scene and I took on a lead role designing and building the database to support Barclays as they combined their many business to build one marketing database.
Barclays demands were high, expecting blistering performance from the OLTP (web based) application and the overnight batch process, I spent many an hour tuning and tweaking code, indexes, execution plans etc. to get the most out of the database.
Following completion of Barclays and a brief spell on some work for HBOS and Argos I moved onto a smaller business utilising Oracle Forms & Reports. With an online and batch system running on the same server, same schemas I quickly picked up the necessary DBA skills to make the most of the machine and Oracle 10g database. Passing on my knowledge via training developers both new or experienced using Oracle.
From the smaller firm it was back to the corporate world taking on a role with E.ON to bring into a line a 2Tb database with access to several application databases and used for MI reporting, workflow and adhoc web applications. Taking on 700+ batch jobs and 300+ users with many queries exceeding 12 hours to complete it didn’t take long to make a big difference in run times and database availability and reliability.
More recently I have been in a team supporting a 16Tb Oracle Data Warehouse specifically looking into performance bottlenecks and developing an OBI+EE reporting suite opening the users eye to how busy the database is, when the quieter periods are, how the user affects the database in terms of CPU, Temp Table Space, Memory etc. Users can see all queries run in the last 30 days or so and compare the query performance over time where a query is repetitive. Other work has included further batch developments and additional reporting suites via OBE+EE Answers and Dashboards.
Over the various roles I have picked up a wealth of experience in the different database environments from on-line to batch and combining the two on the same machines and databases. Working with large tables, many in excess of 100Gb using any combination of data types including CLOB’s and XML Types I have managed to work many queries down from 12+ hours to just a few minutes, in some cases seconds.
I’m no Tom Kyte, Steven Feuerstein or Jonathan Lewis buy I’m happy to look at any Oracle problem and provide some help on how to resolve the problem.