They say better not to use UNDOCUMENTED stored procedures, which is true in the aspect when any Service Pack or version is released that may not be included and your task might have issues in working out. Similar to this I was going through various methods to get information on login mapping name since SQL Server 2000, by using PROFILER and so on. Found that using undocumented stored procedure called sp_MSloginmappings you can get login information that is mapped. If you do not provide a Login Name,...(
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Read the complete post at http://sqlserver-qa.net/blogs/perftune/archive/2007/12/24/3030.aspx