In Business Central SaaS, Indexes are created automatically by suggestion of automatic Azure SQL performance recommendations, referencing article Database advisor performance recommendations - Azure SQL Database | Microsoft Learn, by creating missing indexes, with the goal of the automation being to improve overall performance of the application.

Referencing the article on the logic behind the creation of indexes in Terms of used up database space  -  “If the available storage will be below 10% after the index is created, the recommendation goes into an error state. If after a couple of days automatic tuning still believes that the index would be beneficial, the process starts again.

This process repeats until there's enough available storage to create an index, or until the index isn't seen as beneficial anymore.“ - as of right now there is no possibility to monitor exactly what indexes are being created for the performance improvement, which in turn leads to gigabites of used up limited database space to hold Index attributes.

If indexes are removed, the AL code paths which are affected by their removal with slow performance will trigger the automation to recreate said indexes.

It is essential that partners are able to locate to understand what indexes are taking most of the space and/or have a tool which helps them see the names of the created indexes, their size, information on if they are standard indexes or created by the automation system or if they are custom indexes from an ISV solution which they work with, which can be managed and improved from their side.