Excel Type mismatch error when adding Pivot Table.

When creating a pivot table from an Excel ListObject, it is important to use the R1C1 format when passing the range information to Excel's PivotCaches.Add method. Failure to do so will cause the method call to fail with the message "Type Mismatch" when the number of rows exceeds 65,536.

Performance counters to monitor ASP.NET web site performance.

I found it useful to track the following performance counters when monitoring the performance of a web application.

\.NET CLR Interop(WebDev.WebServer)\# of marshalling
\.NET CLR Jit(WebDev.WebServer)\% Time in Jit
\.NET CLR LocksAndThreads(WebDev.WebServer)\Contention Rate / sec
\.NET CLR Memory(WebDev.WebServer)\# Bytes in all Heaps
\.NET CLR Memory(WebDev.WebServer)\Large Object Heap size
\.NET CLR Security(WebDev.WebServer)\% Time in RT checks
\ASP.NET Applications(__Total__)\Requests/Sec
\ASP.NET\Request Execution Time
\ASP.NET\Requests Queued
\Distributed Transaction Coordinator\Transactions/sec
\Memory\Available MBytes
\Memory\Pages/sec
\PhysicalDisk(_Total)\Avg. Disk Queue Length
\Process(sqlservr)\% Processor Time
\Process(WebDev.WebServer)\% Processor Time
\Processor(_Total)\% Processor Time
\SQLServer:Exec Statistics(Average execution time (ms))\DTC calls
\SQLServer:Locks(Database)\Lock Waits/sec
\System\Context Switches/sec
\System\Processor Queue Length
\Web Service(Default Web Site)\Anonymous Users/sec
\Web Service(Default Web Site)\ISAPI Extension Requests/sec

Caching in Outlook

A very informative KB article on Offline Address books in Outlook. Must read for anyone designing offline support in an application.

Outlook.sharing.xml.obi contains RSS subscription names.
extend.dat is an internal cache file used by Outlook to store paths to all DLL files used for Outlook extensions.