How to become a good conference speaker, from a year of 18 international conferences in 14 countries. Know which room you are in, treat demos like production, protect your health, say no with a ranking list, and speak for the love of it, not for business.
Nonclustered Columnstore Index on a Temp Table in SQL Server
A nonclustered columnstore index works on a temp table but not on a table variable. This post loads a temp table, builds the index, and measures the same aggregate query before and after. It also shows the error a table variable raises and when the build cost pays off.
NEWID vs NEWSEQUENTIALID: What Each Does to Your Index
NEWID vs NEWSEQUENTIALID decides whether new uniqueidentifier keys land at random in your clustered index or in order at the end. This post loads 20,000 rows with each default, measures pages, fullness and fragmentation, and shows the limits of NEWSEQUENTIALID. It also answers what happens when you switch the default on a table that already has rows.
A Daily Streak in SQL: Finding the Longest Run of Consecutive Days
Find consecutive days with gaps and islands, rank the longest streak per user, and define a current streak using the right business date.
Get the Second Row From a Table in SQL Server
To get the second row from a table, first decide what second means, because a table has no order until you give it one. This post builds a small demo and compares ROW_NUMBER, OFFSET and FETCH, and TOP inside TOP. It also covers every second row, the second row in each group, ties and the cost of each method.
Why Query Store Actual Operation Mode is Not Same as Requested? – Interview Question of the Week #248
Question: Why Query Store Actual Operation Mode is Not Same as Requested? Query Regression (poor performing queries, once working great)
Session Wait Stats: Find the Query Behind a Wait Type
Session wait stats tell you which session produced a wait type, and the input buffer tells you which query that session ran. This post shows how to see who waits right now, how to read the wait history of each session, and how to join them to the query text. It also explains the THREADPOOL wait.