Pricing
- How many queried data on a monthly basis is free? 1TB
- What is the price for querying 1TB? $5
- What are two price models? On-demand pricing and flat-rate pricing
- What determines the data processed? Total data per column and column type
- To what degree does BigQuery round pricing? Nearest MB with minimum 10MB per table and 10MB per query
- Can you use the LIMIT clause to reduce processed data? No
- What is active storage? Any table that has been modified in the last 90 days
- What is long-term storage? Any table (or partition!) not modified for 90 days.
- How do long-term and activate storage compare in pricing? Long-term storage is 50% cheaper to store, it’s the price of nearline storage
- What storage is free on a monthly basis? 10GB
- How can you limit data processing costs? Don't SELECT *, partition tables on date, cluster tables, materialize query results in destination tables, denormalize data, use nested & repeated fields
- How can you limit storage costs? Expire large tables, expire partitions, make sure to activate long-term storage
Querying
- What is a slot? A virtual CPU used by BigQuery to execute SQL queries.
- How do slots work? When BigQuery executes a query job, it converts the declarative SQL statement into a graph of execution, broken up into a series of query stages, which themselves are composed of more granular sets of execution steps. BigQuery slots execute individual units of work at each stage of the query. For example, if BigQuery determines that a stage's optimal parallelization factor is 10, it requests 10 slots to process that stage.
- What happens when there are no more slots available? BigQuery queues up individual units of work and waits for slots to become available.
- What are jobs? Actions that BigQuery runs on your behalf
- What job actions exist? Loading, exporting, querying and copying data
- What are *wildcard* tables? They enable you to query multiple tables using concise SQL statements.