There are various name-brand databases that are available in the IT market. The most common database products are Oracle, Microsoft SQL-Server, IBM's DB2 and MySQL.
Rather than using one of these name-brand commercial databases to store Google's search data, as you pointed out, they chose to write their own database called Big Table and GFS or "Google File System".
why? Why would they have done this? Isn't that like reinventing the wheel? Why did they not use a commercial database?
Thoughts?