As a DataWarehouse Solution Google Bigquery is meant more for Large Data Analysis then real time Write/Update. You can go with BigTable instead of BigQuery but be prepare for the hight cost. Also, in most of the Data solution if you are looking for heavy real time Wrire/Update you have to put some cost on the solution. For more detail you can check this link https://cloud.google.com/blog/products/gcp/in-memory-query-execution-in-google-bigquery