| bqschemaupdater is a tool for adding and updating BigQuery table schema. |
| |
| # Usage |
| |
| schemas should be written in .proto format. |
| |
| Bqschemaupdater uses protoc found in $PATH. Please make the latest |
| [protobuf library](https://github.com/google/protobuf) available in $PATH. |
| |
| More information can be had with: |
| |
| ``` |
| bqschemaupdater --help |
| ``` |
| |
| ## Supported Uses |
| |
| The operations supported by this tool include: |
| |
| * Creating a new table |
| * Adding NULLABLE or REPEATED columns to an existing table |
| * Making REQUIRED fields NULLABLE in an existing table |
| |
| # Standard Practices |
| |
| Table IDs and Dataset IDs should be underscored delimited, e.g. `test_results`. |
| |
| ## Schema Definitions |
| |
| Columns in BigQuery tables cannot be modified or deleted once they have been |
| created. However, it is easy to add columns, so err on the side of not adding a |
| column if you are unsure. |
| |
| BigQuery provides useful types such as RECORD and TIMESTAMP. It is a good idea |
| to take advantage of these types. |
| |
| Events usually have an associated timestamp field recording the time the event |
| took place. |
| |
| BigQuery discourages JOINs and encourages denormalizing data. |
| |
| Flattening repeated fields can be costly. If you know that a repeated field |
| will only ever contain 0 or 1 value, consider not making that field repeated. |
| |
| # BigQuery Limits |
| |
| Please see [BigQuery |
| docs](https://cloud.google.com/bigquery/quotas#datasettableupdates) for the most |
| updated limits for creating and modifying tables. It is not expected that we |
| will exceed these limits through bqschemaupdater usage. If you are planning |
| a project which might, please contact the Monitoring Team. |
