Part of umbrella issue 177274.
Less indexes => less IO => better performance.
Tomas, when we have implemented index repository for C++ we have made due diligence and our conclusion was:
it is very slow to have index per file
in our case we have index file per namespace => less indexes
=> you can try to merge indexes per package
>it is very slow to have index per file
Currently we have an index per source root not for file (package).
The goal of this issue is to put all documents for given root into single index.