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Category: Bugs

How To Create A Connect Entry

Kenneth Fisher shows how to create a Microsoft Connect entry:

I recently wrote a blog about how to tell why your SQL login isn’t working. There were a lot of good comments and several of them suggested that I create a connect entry to make the error easier to understand. There was also a question of how to create a connect entry, and it wasn’t the first time I’d heard that, this week. So I’m going to give a quick demo on how to create a connect entry. I’m not going to create it using that particular login error because, as another person pointed out, this error is actually by design. We don’t want to make it easier for someone trying to hack in right?

There are also feedback forums for Power BI and Azure.

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Replication And Date Conversion

Jeffrey Verheul digs up a strange replication bug:

After a lot of different variables in the test-setup, I found out that it’s probably an old bug that wasn’t properly patched when upgrading the SQL Server engine to a newer version. Let me elaborate on that:

– The bug is reproducible on the test server, which is an upgraded engine from SQL 2012 or 2014 to SQL 2016 RTM
– The bug is reproducible on the production server, which is an upgraded engine from SQL 2014 to SQL 2016 RTM
– The bug is not reproducible on a clean install of SQL 2014
– The bug is not reproducible on a clean install of SQL 2016 RTM
– The bug is not reproducible on a clean install of SQL vNext CTP

There’s a lot of good investigative work here, so check it out.

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Most-Voted Connect Items

Adam Machanic peruses the top-rated Connect items:

Magic numbers! That sounds cool. Except it’s not. It’s a horrible drain on readability and a pox on the manageability of your code. But we need them, because every database out there has “lookup tables” with specific values that we need to predicate on throughout the code base. SQL Server could solve this problem once and for all by allowing users to promote these values to named enumerators. How cool would that be?!? 220 votes, nine years.

And finally, one more from Mr. Ben-Gan, a clever idea for improving TOP with the OVER clause. I love the OVER clause. I love TOP. Their offspring would be beautiful indeed… 180 voters over the past nine years have shared in this sentiment.

This is an interesting list.

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String Or Binary Data

Lori Edwards wants to fix one of the most annoying error messages in SQL Server history:

The Connect item that I’m promoting today is Connect #339410 : Please fix the “String or binary data would be truncated” message to give the column name. This Connect item was opened in 2008 and has 1,328 upvotes. If we can create virtual realities, we should be able to add a column name to an error message. Help us Microsoft, you’re our only hope.

This error message is incredibly annoying, particularly because it seems the engine should know which record has an error and on which column that error is.  We finally got information on which row caused a primary or unique key constraint violation, and that was helpful; this would be at least as helpful.

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Connect Items Galore

Aaron Bertrand has a series of Connect items of interest:

There are so many active Connect items, it’s difficult to choose just one, but after spending some time looking at the generate_series function in PostgreSQL, the one at the top of my list right now is this suggestion from Erland Sommarskog (blog):

Connect #258733 : Add a built-in table of numbers

I think it would be cheap and easy for SQL Server to provide a defaut table of numbers, always in memory, just like any other catalog view or DMV. This thing can use compression now, regardless of edition, so even a table with 2 billion rows will only take 13 MB, and should be easy to populate either at start-up or on first use. I could list out all of the potential uses for a numbers table, but they’re fairly well documented in the following sources (and most use cases don’t need anywhere near 2 billion values, so maybe the range could be defined using a sys.configurations or database-level SCOPED CONFIGURATION setting)

Click through for additional Connect items, and please vote on any Connect items which catch your eye.

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The Halloween Problem

Kenneth Fisher explains the Halloween Problem:

What is The Halloween Problem?
This is a bit more complicated. Let’s say you are trying to give a 10% raise to everyone who makes less than $25k.

Couple of quick notes here. This is a common example because this in fact the problem that exposed the issue. Also, while UPDATEs are probably the easiest way to explain what’s going on, it can affect any type of write.

So back to our update statement. There are several ways this could be implemented. I’m going to use pseudo T-SQL to demonstrate a couple and explain each.

This has certain implications as you can see in the linked Paul White series.  These implications typically mean slower performance (e.g., by forcing spooling) but getting rid of a potentially nasty problem.

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Stretch Database Authentication Failures

Jack Li walks through a bug in Stretch database:

The message provided enough directions.  It says either you have a bad login or firewall setting on the Azure DB Server side is not configured correctly.     The very first thing is to ensure the Firewall was configured correctly.   We even tried 0.0.0.0. to 255.255.255.255. But it didn’t resolve the issue.

Next we created a brand new database on the same server and tried on that one.  It worked.  But customer just couldn’t get the old database to work even she made sure that she could use the login/password to log in using SSM on the same server to the Azure DB server.

On the same server, brand new database worked but the old database didn’t.   So that made me wonder what happens if I manually cause an failure and later retry.

Read on for the repo and solution.

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Threads Need Memory Too

Arun Sirpal notices a bug with fn_dump_dblog():

Using this command creates more threads and hidden schedulers (these will only go after a restart). Depending on what version of SQL Server you are on and what Service Pack you may or may not have this issue. It was fixed in SQL 2012 SP2 onwards. So be on the cautious side when running these sorts of commands.

Also I noticed Memory bloat for the sqlservr.exe. Nothing else was running on this server, just my fn_dump_dblog script.  Threads need memory too.

It’s good advice.  Undocumented functions are probably more likely than documented functions to contain bugs.

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Emoji In SQL Server

Daniel Janik wants to have a ninja cat riding a T-Rex for a database name:

There it is! The ninja cat database! You can see that even IntelliSense shows the ninja cat. Cool, right? How does it show in Object Explorer?

DOH! There’s obviously something strange going on here. Let’s validate the sys.databases table:

If full emoji support is the thing keeping you from moving to SQL Server, you might have to wait until the next version.

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