You have to assume that there will be replication lag. Having said that, chopping up long queries into smaller ones (if using replication) is a good rule of thumb.

Quoted: And the final advice - do not assume very short lag time when planning your application. Having application which can adapt to lag time rather than break is very good idea. Especially it will be handy when you will be reaching replication capacity and will need to buy time to fix things, during which replication lag can be higher than normally.

Looking for a free profiler for .Net

Quoted: ProfileSharp® is an open source .NET code, performance and memory profiling software that helps you pinpoint performance bottlenecks in your .NET code and optimize memory usage.

Quoted: Today I would like to share practical example when you may use long primary key with value distribution far from sequential.
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This table is getting much more reads than writes so transactional overhead of for writes is small price to pay for number of benefits - caching data and index in memory -so cached lookups are very fast, clustering by primary key

Quoted: For instance, you may want your cache to be varied based on some internal state and/or property of your application. I'll use an example to demonstrate...

Some great tips in here.

Quoted: Web App Follies: Keep Sites Running Smoothly By Avoiding These 10 Common ASP.NET Pitfalls -- MSDN Magazine, July 2006
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LoadControl and Output Caching
Sessions and Output Caching
Forms Authentication Ticket Lifetime
View State: The Silent Perf Killer
SQL Server Session State: Another Perf Killer
Uncached Roles
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We're using 1.0.7 -- making these changes has helped our performance in our test environment.

Quoted: The 2 I'm mainly interested in are CacheServerConfig and ResetPooledConnections, as in 1.0.7 these made such a difference that (for our application) the connector went from unusable to very efficient. Now, with the 1.0.9 source, it looks like the 3 accepted options for connection reset ("reset pooled connections", "resetpooledconnections", "reset connections") have been replaced with 1: "connection reset". As for CacheServerConfig, it simply doesn't exist any more. The code where it came into play has been changed (if my quick interpretation is correct) to always behave as if it were set to TRUE in 1.0.7. What's the logic of *removing* configurability?

Quoted: Looking at how people are using COUNT(*) and COUNT(col) it looks like most of them think they are synonyms and just using what they happen to like, while there is substantial difference in performance and even query result.

Quoted: Now as new MySQL Storage engine - Falcon is public I can write down my thought about its design, which I previously should have kept private as I partially got them while working for MySQL.

Quoted: In this article, I'm going to present 10 tips for writing high-performance Web apps. I'm not limiting my comments to ASP.NET applications because they are just one subset of Web applications. This article won't be the definitive guide for performance-tuning Web applications—an entire book could easily be devoted to that. Instead, think of this as a good place to start.