Also read Bigquery Partitioning Overview - Clustering versus Partitioning  and File Formats for Loading Data into BigQuery

BigQuery is designed to receive very large amounts of data efficiently.

There are three primary methods for ingesting data into BigQuery

  1. the BigQuery Jobs API
  2. streaming writes and
  3. writing query results into a table.

Other methods, such as loading CSV files from Cloud Storage and using BigQuery as a Cloud Dataflow sink, fall into one of the three primary ingestion methods.

Query Performance

Data Partitioning and Clustering are used to improve query performance. These are separate from the process of data ingestion.