When I use Add Folder to Workspace, codebase indexing is triggered repeatedly

Let’s assume my project structure is as follows:

root/
root/fold1/
root/fold1/■■■/fold1_1/
root/fold1/■■■/fold1_2/

Because fold1 contains useful memory.md files that guide the work within fold1_1, I need to keep fold1 accessible in my workspace, rather than just opening fold1_1 directly. Additionally, I need to primarily focus my work within fold1_1 (which represents a specific experiment folder).

To achieve this, I have set up a VS Code multi-root workspace where I’ve added both fold1 and fold1_1 as separate root folders.

The problem is that now, the codebase indexing feature indexes the contents of fold1_1 twice: once as a subdirectory scanned under the fold1 root, and again as its own separate fold1_1 root added to the workspace. This duplicate indexing is causing a severe performance loss.

Codebase indexing should first verify deduplication of file paths and then perform indexing.

If you index root first and then add fold1_1 to the working area, the indexing will be very fast and will not trigger duplicate indexing. After fold1_1 is added to the working area, if you delete the index and perform indexing again, the indexing will be very slow at this time.