(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
A prior student emailed me yesterday about some strange behavior of the sample_ms column in sys.dm_io_virtual_file_stats. It’s supposed to be the number of milliseconds since the SQL
(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
(The Curious Case of… used to be part of our bi-weekly newsletter but we decided to make it a regular blog post instead so it can sometimes be more
Earlier this year I was sent an interesting question about why the person was seeing lots of VLFs in the log with status = 2
At least since I started working on the SQL Server team (just after 7.0 shipped) and since then there have only been two VLF status
A question came up on the Data Platform MVP email list last night asking what the FCB_REPLICA_SYNC spinlock is. I answered the question and then
A while back I was involved in an email thread where people were wondering about some ‘weird’ behavior from SQL Server. The problem was occurring on
SQLskills has an ongoing initiative to blog about basic topics, which we’re calling SQL101. We’re all blogging about things that we often see done incorrectly, technologies used the wrong
As Kimberly blogged about recently, SQLskills is embarking on a new initiative to blog about basic topics, which we’re calling SQL101. We’ll all be blogging about things that
An interesting question came up in class yesterday: how is a default column value stored, and what if some rows exist when a column is added and then
Last week there was a short discussion on Twitter about why PFS pages (damaged header, not individual PFS bytes) can’t be repaired (prompted by a
Last week I was sent an email question about the cause of LOGMGR_RESERVE_APPEND waits, and in Monday’s Insider newsletter I wrote a short explanation. It’s
In Monday’s Insider newsletter I discussed an email question I’d been sent about how to identify the transactions that had rolled back because of a crash, and
This is something that came up recently on the Microsoft Certified Master DL, and is something I discuss in our IEPTO1 class because of the
The pages at each level of an index are linked together in a doubly-linked list (using the m_nextPage and m_prevPage fields in their page headers)
Over the weekend there was a discussion on the MVP distribution list about the sys.dm_tran_database_transactions DMV and how one cannot use it to accurately determine
An interesting corruption problem cropped up on the MCM distribution list yesterday and after I figured it out, I thought it would make a good
Last weekend there was a suggestion on the MVP distribution list about having temporary nonclustered indexes on AG readable secondaries, in the same way that
Back in 2009 I blogged about how checkpoints work (see How do checkpoints work and what gets logged) and I received a question in email
Since SQL server 2014 was released back in April last year, there have been some rumblings about changes to how many VLFs are created when
It’s been a bit light on technical posts here over the last few months but now that summer’s over I’ll be ramping up again with
This is a question that came up this morning during our IE1 class that I thought would make an interesting blog post as there are
It’s been a long time since I’ve written a post about pure internals, but every so often I get asked how an allocation unit ID
All kinds of little bits of information have been added to the output of various DMVs, functions, and commands in SQL Server 2012. One which
In my previous post I explained how the sp_configure settings are stored in a special page in the master database called the CONFIG block. Sometimes
Earlier today I blogged on our SQL Server Pro magazine blog about false-alarm corruptions you will *definitely* see if you restore a backup of the
Earlier today there was a question on the MVP mailing list asking how SQL Server keeps track of per-column modification counts. From 2008 onwards, the
This is a question that came up today on Twitter, and is actually something I’ve been meaning to blog about. One of the biggest space
We're teaching on-site with a financial client in New York for two weeks and in a session this morning on log file architecture I was
There was an interesting discussion on Twitter this morning (started by my good friend Erin Stellato (blog|twitter)) about in-place updates for index records where the
(Look in the Misconceptions blog category for the rest of the month’s posts and check out the 60-page PDF with all the myths and misconceptions
(Look in the Misconceptions blog category for the rest of the month’s posts and check out the 60-page PDF with all the myths and misconceptions
(Look in the Misconceptions blog category for the rest of the month’s posts and check out the 60-page PDF with all the myths and misconceptions
(Look in the Misconceptions blog category for the rest of the month’s posts and check out the 60-page PDF with all the myths and misconceptions
Way back in the mists of time, at the end of the last century, I wrote DBCC SHOWCONTIG for SQL Server 2000, to complement my
I've blogged about ghost records and the ghost cleanup task a couple of time before (the only place it is really explained AFAIK), but one
One of the things I love teaching is how the transaction log and logging/recovery work. I presented a session on this at both PASS and
Last week I posted in-depth about how checkpoints work and what exactly goes on (see How do checkpoints work and what gets logged). About a
(Check out my Pluralsight online training course: SQL Server: Logging, Recovery, and the Transaction Log.) This is a blog post I’ve been meaning to do
I'm constantly surprised by the number of people that don't follow the CSS SQL blog – some of the best SQL people in the industry
Here’s a question that came up recently: if I’ve upgraded a database from SQL 2000 or before, how can I tell if the data purity
This is a question that comes up every so often, most recently this morning while teaching a private class (and Kimberly's teaching now): how large
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