Portfolio     Data Migration Challenge: Customer had two versions of database: production and development. There was a big difference between these two databases in database structure and stored procedures. The customer wanted to migrate data from development database to previously updated production database.Solution: At first glance task seemed quite simple, but the challenge was that the database structures (hundreds of tables) were quite heterogeneous and that some of data existed in both databases. We developed universal data migration solution that allows merging data from one database with data from another database. The restriction was that database structures should be the same version.Results: Final solution consists of a command file and SQL scripts which could be run by one press.Technologies and tools: PL-SQL, SQL Plus, Oracle 9i. System Response Increase  Challenge: Our customer has very low system response due to huge amount of data in Oracle database. Their system collected more than 6 gigabytes of data monthly, so every month their application has been becoming slower and slower.Solution: We have analyzed customer's data and suggested two-step solution. First step was renormalization of some tables' structure and rewriting the application query according with new database structure. Implementation of this step increased system performance twice holds. Second step was tables partitioning which has allowed us to improve system response extremely. Results: It takes now seconds to execute queries that had taken hours before.Technologies and tools: Oracle 9i, Oracle 10g, Oracle Partitioning Load Tool Challenge: Customer wanted to develop utility which would load files from server file system to database. Files should be loaded from the same server where database is installed. This restriction was specified because loading solution should have been written on PL/SQL only.Solution: We developed PL/SQL packages which load files into database using Oracle UTL API. It is the fastest loading solution comparing with loading BLOB data into database from JAVA or .NET applications developed by our company.Technologies and tools: Oracle 10g, PL/SQL, UTL API.