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Category: Error Handling

System Views and Distributed Processing in Microsoft Fabric

Published 2024-06-10 by Kevin Feasel

Koen Verbeeck runs into an annoying error:

I have a metadata-driven ELT framework that heavily relies on dynamic SQL to generate SQL statements that load data from views into a respective fact or dimension. Such a task is well suited for generation, since the pattern to load a type 1 SCD, type 2 SCD or a fact table is always the same.

To read the metadata of the views, I use a couple of systems views, such as sys.views and sys.sql_modules. At some point, I join this metadata (containing info about the various columns and their data types) against metadata of my own (for example, what is the business key of this dimension). This all works fine in Azure SQL DB or SQL Server, but in my Fabric warehouse I was greeted with the following error:

The query references an object that is not supported in distributed processing mode.

Read on to learn more about why you get this error and one workaround for it.

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Power BI Command Memory Limit

Published 2024-06-04 by Kevin Feasel

Chris Webb is overdrawn at the memory bank:

Continuing my series on Power BI model memory errors (see part 1 and part 2), in this post I will look at the Command Memory Limit which restricts the amount of memory that XMLA commands like Create, Alter and most importantly Refresh and can use.

If you’ve ever been told that your semantic model should consume less than half the amount of memory available to it because memory consumption can double during a full refresh, then that is because of the Command Memory Limit. 

Read on to learn more about the Command Memory Limit and why this advice exists.

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Unhelpful Error Restoring Azure SQL MI Database

Published 2024-05-31 by Kevin Feasel

Kendra Little encounters an error:

What’s it like to be a Database Administrator for managed databases in Azure? Sometimes it’s a painful guessing game when a routine, core operation– restoring a database – fails with a most unhelpful error.

In this case, if the restore is run via PowerShell, following Microsoft guidance, the error message is:

Restore-AzSqlInstanceDatabase: Long running operation failed with status ‘Failed’. Additional Info: An unexpected error occured while processing the request. [sic]

Somehow the misspelling of ‘occurred’ stings a bit more. Did anyone review the PR for this code?

I’m trying to weigh in my mind whether this error is worse than “String or binary data would be truncated.” One the one hand, the spelling is correct in the latter error message. On the other hand, it uses passive voice. On the gripping hand, they’re both nigh-useless error messages. Hopefully the SQL MI team fixes Kendra’s error message at least as well as the database engine fixed the latter.

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Concatenating Strings and (N)VARCHAR Truncation

Published 2024-05-28 by Kevin Feasel

Vlad Drumea troubleshoots a common problem:

The code in this case is the GetStatsInfoForWholeDB.sql script that’s part of PSBlitz’s resources.
This script is used for, you wouldn’t believe by the name alone, getting statistics information for a specific database.

Due to the fact that it might be ran on Azure or on older versions of SQL Server, as well as on databases with incremental statistics, the best option for it was to use dynamic SQL.

In this case it uses a variable @SQL defined as NVARCHAR(MAX) to store the query that’s built at runtime and execute it via EXEC.

Read on for one of the most common issues you may run into around generating dynamic SQL.

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Dangling Images with Oracle 23ai Free Edition

Published 2024-05-10 by Kevin Feasel

Kellyn Gorman runs into an issue:

When I tried to connect via SQLPlus as SYSDBA, I received an EXTPROC error. It pointed clearly to the listener.ora file, which I discovered a path listed still to ora23c for the extproc, corrected it, started the Listener, but to no avail- an ORA-12547 error, realizing I had a make file issue on the binaries for Oracle.

I contacted Geral Venzl, who was very gracious and after some quick research, he came back that his folks said everything was fine with the images, so I thanked him and dug into the issue deeper.  I quickly discovered this problem could happen to others, so decided I better document here for anyone who does happen upon it.

Click through for the high-level explanation and a bit more detail on dangling images.

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Missing Log Information after a VM Rollback

Published 2024-05-07 by Kevin Feasel

Jonathan Kehayias (via Paul Randal) advises caution:

Recently I received an email with a very vague description of a problem that went something along the lines of:

“After some issues with Windows patching and rolling back from snapshots, our cluster resources won’t come online. In the process of troubleshooting the issue and validating the fix, we rolled back a few times. We can’t find any details about the issue in the cluster logs, Windows event logs, or SQL Server error log to investigate further.”

Read on for more information about the immediate problem, the root cause, and the actual issue the customer ran into before compounding the problem.

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Max Offline Semantic Model Size Error

Published 2024-05-06 by Kevin Feasel

Chris Webb continues a series on Power BI semantic model memory errors:

In the Power BI Service, Import mode models are stored offline and paged into memory only when they are needed – for example because someone runs a report that uses the model as its source. As discussed in my last post, though, there’s a limit on the amount of memory that a model can use which varies by the size and type of capacity you’re using using. There’s also an extra complication in that Import mode models are stored offline in a compressed format that means the Power BI Service doesn’t know exactly how much memory will be needed if the entire model needs to be held in memory. As a result there is an additional limit enforced on the size of the offline copy of Import mode models to ensure they don’t use too much memory when they are eventually paged in.

Read on to learn more about this setting and what it looks like if you trigger the error.

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