text: Title: Database Connection per Schema
  Body: * GINO version: 0.8.6
  * Python version: 3.7.0
  * asyncpg version: 0.20.1
  * aiocontextvars version: 0.2.2
  * PostgreSQL version: 11 
  
  ### Description
  
  We're trying to implement our database logic to be a single connection to a schema in a database, meaning that we use schemas as databases themselves to maintain our connection pool. We need this since we don't want to connect to different databases as this affects our performance, but we still need to separate the information between different schemas as its client specific.
  
  Currently we are doing this for each new request (because each request could be related to a different client and we need to set a new client schema):
  ```
  async def adjust_schemas(self):
          """Adjust schemas on all model tables."""
  
          for table_name, table_dict in self.__db.tables.items():
              table_dict.schema = self.__schema
  ```
  but most probably you can already guess that this messes up with requests that have still not finished giving a response, since the schema could change from a different request and data would go into the wrong client schema.
  
  We can't find any straightforward solution for this. Do you think we can achieve this with Gino?
  
  