An error occurred while processing the data in the semantic model.

[sudheer1437]

We have a powerbi report pulling data from MySql tables/views.

we are using bunch of views. and we refresh the symantic model every 1hr to refresh the data.

Every other run, sometimes continuously 3 to 4 runs, the refresh fails with below error

has failed to refresh.
Failure details: The last refresh attempt failed because of an internal service error. This is usually a transient issue. If you try again later and still see this message, contact support. 
{"error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","pbi.error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","parameters":{},"details":[{"code":"DM_ErrorDetailNameCode_UnderlyingErrorCode","detail":{"type":1,"value":"-2147467259"}},{"code":"DM_ErrorDetailNameCode_UnderlyingErrorMessage","detail":{"type":1,"value":"<ccon>MySQL: The table 'E:\\Mysql\\temp\\#sqlbe8_13b890_13' is full</ccon>"}},{"code":"DM_ErrorDetailNameCode_UnderlyingHResult","detail":{"type":1,"value":"-2147467259"}},{"code":"Microsoft.Data.Mashup.ValueError.DataSourceKind","detail":{"type":1,"value":"MySql"}},{"code":"Microsoft.Data.Mashup.ValueError.DataSourcePath","detail":{"type":1,"value":"<ccon>server1;schema1</ccon>"}},{"code":"Microsoft.Data.Mashup.ValueError.ErrorCode","detail":{"type":1,"value":"-2147467259"}},{"code":"Microsoft.Data.Mashup.ValueError.Message","detail":{"type":1,"value":"<ccon>The table 'E:\\Mysql\\temp\\#sqlbe8_13b890_13' is full</ccon>"}},{"code":"Microsoft.Data.Mashup.ValueError.Reason","detail":{"type":1,"value":"DataSource.Error"}}],"exceptionCulprit":1}}} Table: view1.

Any help to fix the above issue is highly appreciate.

PS: i am fairly new to PowerBI and in learning phase. 

[rajendraongole1]

Hi @sudheer1437 - The error message you’re encountering is not strictly a Power BI issue. It relates to your MySQL database, specifically regarding a temporary table (#sqlbe8_13b890_13) being full. This happens when MySQL runs out of disk space or cannot allocate more temporary storage.

A. Check and Free Up Disk Space
Log into the MySQL server and check the disk space on the E: drive.
Use tools like df (Linux) or check File Explorer (Windows) to identify files consuming space.
Clean up unused files, logs, or large temporary files from the E:\Mysql\temp directory.
Tip: Use SELECT @@tmpdir; in MySQL to check the current temporary directory.

B. Move the MySQL Temporary Directory
If E:\ is running out of space, consider moving the temporary directory to a larger disk:

Edit the MySQL configuration file (my.cnf or my.ini):

[mysqld]
tmpdir = "D:/Mysql/temp"

Replace D:/Mysql/temp with a path to a disk with sufficient space.

Restart the MySQL service for the changes to take effect.

C. Optimize Your Views
Power BI queries may trigger large, inefficient MySQL operations:

Review Views: Simplify the SQL logic in the views to avoid excessive joins, sorts, and calculations.
Add Indexes: Ensure that views are querying indexed columns to speed up performance and reduce temp table usage.
Split Queries: Break large queries or views into smaller, incremental ones.

By addressing the disk space and optimizing your MySQL views, you can resolve this error and ensure reliable data refreshes in Power BI.