"database is locked"

[rdflib]

"database is locked"

[mwatts15]

It's difficult for me to say without a small, self-contained example of the issue you are experiencing, but it looks like SQLite isn't designed for a high degree of write concurrency which may be important to consider for your use-case.

With regard to pooling, rdflib-sqlalchemy creates one SQLAlchemy Engine for every instantiation of the store, so if you want to take advantage of connection pooling at that level, then you'd probably want to reuse the same RDFLib Store/Graph. Also note that you can pass arguments to create_engine if needed to tune connection pooling parameters.