Scientific computing has two parallel data needs, one the physical values of the data itself, and the other is Database systems to manage the data. In this document links are provided only to database resources on the net and free Database systems. I personally do not use databases to manipulate the data generated by my codes. gawk, sed, and other basic Unix commands like grep, head and tail seem sufficient to manipulate any data I generate. I thought I should include this section for the large data generators. Hopefully a person with experience in databases will make this section better.
ACM SIGMOD: Index of publicly available database software.
MySQL: A relational Database management system.
PostgreSQL As the link above describes it ...PostgreSQL is a sophisticated Object-Relational DBMS, supporting almost all SQL constructs, including subselects, transactions, and user-defined types