dbt opening multiple connections to target database - how to restrict number of parallel connections

[josepaul1988]

Tested with different versions of dbt-bigquery as well as dbt-postgres adapters. It seems like even with threads=1 dbt is initating one master connection and another set of connections for each schema defined in the dbt_project.yaml. In our project we cannot use more two connections concurrently to target database. is there a way or configuration that we can use to ensure strictly the number of connections made to the target database. From logs we could see the connections are initiated like below

[0m16:42:27.610328 [debug] [MainThread]: Acquiring new bigquery connection 'master'
[0m16:42:27.671724 [debug] [ThreadPool]: Acquiring new bigquery connection 'list_gdp-project-id'
[0m16:42:27.674011 [debug] [ThreadPool]: Opening a new connection, currently in state init
[0m16:42:32.247486 [debug] [ThreadPool]: Acquiring new bigquery connection 'list_project-id_staging'
[0m16:42:32.249455 [debug] [ThreadPool]: Opening a new connection, currently in state init
[0m16:42:32.250455 [debug] [ThreadPool]: Acquiring new bigquery connection 'list_project-id_pre_consumption'
[0m16:42:32.252455 [debug] [ThreadPool]: Acquiring new bigquery connection 'list_project-id_consumption'