What is transction log in exchange server.

Question

What is transction log in exchange server.

Answer 1

The Information Store (IS) and Directory form the core of Microsoft Exchange Server. Systems administrators expend a great deal of effort to protect these databases. Administrators use RAID 5 or RAID 0+1 disk configurations to protect data; perform frequent backups; and carefully plan the stores' location on their servers' available disk volumes. I applaud systems administrators who take these precautions—the IS and Directory need as much protection as possible. But administrators mustn't limit data protection for Exchange Server to the databases. The databases' transaction logs (the IS and Directory each have a set) need protection too.

The IS and Directory use a write-ahead transactional model to protect data. Before Exchange Server commits data to one of the stores, it writes the data to a log file. Exchange Server logs every IS and Directory transaction from every source. After a transaction occurs, Exchange Server records it in the current log and writes the modified database pages to a memory cache. When system load permits, Exchange Server commits the pages in the cache to the appropriate store. . . .