Be
thankful things have changed since then.
Client Connections with the SQL Native Access Client
Although database mirroring has value regardless of how you connect to the server
(there??™s always the possibility of a manual or automated client-side failover process),
the only way to achieve truly seamless failover from a client perspective is to use SNAC.
SNAC is technically just the SQL Server 2005 OLE DB driver, but it requires installation
on all client machines for database mirroring automated failover to work as advertised.
When a client using SNAC connects to a principal database participating in a mirror
operation, it immediately receives information about the location of both the
CHAPTER 8 n DATABASE MIRRORING 204
mirror and the server. Should the principal fail, the SNAC-enabled client will automatically
redirect further database requests to the mirror (which should now be the principal).
You don??™t need to rename any servers, change any database connections, or
modify any DNS entries.
As Figure 8-10 illustrates, the client immediately learns the following facts:
??? Server A and Server B are in a mirroring session.
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