SQL Server was originally developed by Sybase in the mid-
1980s and licensed to Microsoft until 1997. Even today,
most of the core technology in SQL Server is the same as
Sybase Adaptive Server Enterprise. Architecturally, Sybase
and Microsoft are very similar, and both use the Transact-
SQL dialect of SQL that is copyrighted by Sybase. To this
day, Sybase receives a royalty for every copy of SQL Server
sold.
Key architecture points:
1. Multi-threaded, scales to multiple processors
2. Main databases are master, model, tempdb
3. Each database has at least one data segment and one
log segment
4. Transaction log is used for rollback and recovery