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Category: Bugs

Bug in fn_xe_file_target_read_file

Published 2023-07-17 by Kevin Feasel

Erik Darling notes a bug:

SQL Server has had the fn_xe_file_target_read_file function for a while, but starting with SQL Server 2017, a column called timestamp_utc was added to the output.

Somewhat generally, it would be easier to filter event data out using this column… if it worked correctly. The alternative is to interrogate the underlying extended event XML timestamp data.

That’s… not fun.

Erik shows us the problem and also provides a workaround, as well as the Microsoft Feedback issue you can vote on to get this done sooner.

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Bugs in SQL Server 2022 CU4

Published 2023-05-29 by Kevin Feasel

Brent Ozar facepalms:

<sigh> Okay, so, the last few Cumulative Updates have had known issues around broken remote queries using the generic ODBC connector and errors with contained availability groups, but I couldn’t really care less about those. If you use those features, I give you bombastic side eye anyway.

However, in the last few days, two more known issues have surfaced.

And those two issues are definitely bad. Click through to see what they are and what the workarounds are until fixes come in.

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PolyBase Generic ODBC Bug in 2019 CU19 and 2022 CU2

Published 2023-04-06 by Kevin Feasel

Nathan Schoenack warns us of a bug in SQL Server:

After you install SQL Server 2019 CU19 or SQL Server 2022 CU2, external data sources using generic ODBC connector may no longer work. When you try to query external tables that were created before installing the cumulative update, you receive the following error message:

Msg 7320, Level 16, State 110, Line 68

Cannot execute the query “Remote Query” against OLE DB provider “MSOLEDBSQL” for linked server “(null)”. Object reference not set to an instance of an object.

If you try to create a new external table, you receive the following error message:

Msg 110813, Level 16, State 1, Line 64

Object reference not set to an instance of an object.

Click through to learn the cause of the issue and a workaround to resolve it.

2 Comments

Notes on DBATools’s Get-DecryptedObject

Published 2023-01-26 by Kevin Feasel

Sean Gallardy explains an issue:

Let me start off by saying that DBATools is a great tool that is immensely helpful to the community, if you haven’t heard about it or tried it, please give it a shot! I personally believe that the SQL Server community is truly the best out there, with so many people helping each other and developing great, free, tools that benefit all. Having said that, I’ve been asked quite a few times to look into a “SQL Server Bug” decrypting data.

This is not an issue with SQL Server nor is it a bug/feature/whatever. It is, in fact, a bug in the source material for DBATools.

Read the whole thing.

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Tracking Database Errors with Extended Events

Published 2022-12-07 by Kevin Feasel

Eitan Blumin is watching you:

But interestingly enough – we would be getting an added benefit here. Even if there is no SQL injection attack, it’s still possible that such errors would be raised by the application – simply due to bugs.

Furthermore, these errors in the database may be happening without anyone even noticing! How could that be, you ask? Well, it could be due to bad error handling that “swallows” the error entirely, or because the errors are logged but no one is bothering to look at the logs, or maybe because the errors are caught but an undetailed error message is logged/displayed to the user (I can’t even count how many times I encountered “general database error” messages in applications), or because the developers simply decided to mark this as a “known issue” that they didn’t bother to fix and they didn’t think to ask their DBA about it… The reasons are numerous and varying.

Click through for the scripts. I had built something similar about a decade ago, a simple WPF app which watched for errors. I messaged him with something like “You missed a comma in that IN clause” and I saw him pop up from his cubicle and look around, trying to figure out how I could peek over his shoulder and see the query.

1 Comment

Debugging Code in R

Published 2022-10-06 by Kevin Feasel

Cosima Meyer explains how debugging works in R with RStudio:

Three basic commands in RStudio let you do the debugging: debug(function_name), browser(), and undebug(function_name).

With debug(function_name) you start the debugging of your function – it’s basically like a mole that digs in. When you’re in debug mode, you can also call the objects in your function.

Read the whole thing to learn the power of debugging beyond the print() statement. H/T R-Bloggers.

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Triggering Dumps for Specific Errors and States

Published 2022-09-29 by Kevin Feasel

Bob Dorr has a plan:

I had an inquiry about dbcc dumptrigger today and realized that state filtering was added to dbcc dumptrigger but not well known.

You can collect a process dump (SQL Dumper) when a specific error occurs using XEvent (error_reported/ex_raise2 events with dump capture action) or dbcc dumptrigger.

The common use of dbcc dumptrigger is: dbcc dumptrigger(‘set’, 208) to produce a dump when error 208 is encountered.

This is pretty useful, especially if you’re troubleshooting a bug in the database engine.

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Breaking Changes in Azure Data Explorer Window Functions

Published 2022-09-07 by Kevin Feasel

Gabi Lehner announces an upcoming bugfix:

This is a Breaking change when using window functions inside partition operator sub-query scope.

Window functions require a serialized/ordered input.

There is a bug in Azure Data Explorer logic that allows using window functions inside the partition operator when the ordering is performed outside the partition query scope like this:

Click through for what currently works as well as its future replacement.

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