Thank you all for prompt replies. I've added logging to Go's stdlib and confirmed that this is really a database/sql behaviour to create more connections, as suggested by anonymous (5). Code in question doing this is here: https://golang.org/src/database/sql/sql.go?s=47934:48006#L1303. Thank you Keith for explaining, now I understand the tx/connection mechanics a bit better. Thanks Holger for suggesting working with bare sqlite, I'll keep that in mind with further experiments.