Extremely slow Power Query and Power BI Desktop

[Ramakko]

Hello everyone, I work on a DB that doesn't have much data inside, but it's a rather ramified DB because it collects data from company survey questionnaires and the different dimensions connected to them... The problem is that, by now, even when I simply modify the name of a field of a query, both power query and, even more, the upload of the changes in Power BI Desktop has become exhaustingly long: half hours pass!!!! I read another forum post where you talked about cleaning the data already knows Sql, but I don't use it: my sources are mostly excel sheets... I've already split the main query into several concatenated queries, with max 5 -6 passes each, but nothing has changed!!!!

[Ramakko]

Thank you @lbendlin for your answer, it was really a data source problem: I had to replace the import from folder to reduce processing times

[lbendlin]

Every little change in the structure of your data sources will be used by Power Query as an excuse to refresh the meta data (the dreaded "Evaluating"  black hole).  Try to keep your sources stable.