In a DBT (Data Build Tool) project, seed-paths configuration in the dbt_project.yml file is used to specify the directory or directories where seed data files are located. Seed data is a set of initial data used to populate a database table or view, and is often used as a starting point for a data pipeline.
Here’s a detailed explanation of seed-paths in DBT:
- Syntax: In the
dbt_project.ymlfile,seed-pathsis specified as a list of directories or a string containing a single directory path. For example, the following configuration sets theseed-pathsto a single directory nameddata/seed:
seed-paths: "data/seed"
If you have multiple directories containing seed data files, you can specify them as a list:
seed-paths:
- "data/seed1"
- "data/seed2"
- Placement: The
seed-pathsconfiguration should be placed in thedbt_project.ymlfile, typically near the top of the file. - File formats: Seed data files can be in various formats such as CSV, JSON, or YAML. DBT supports a wide range of file formats, including Excel, Google Sheets, and XML.
- File naming convention: DBT expects seed data files to be named in a specific format, where the filename matches the name of the table or view that the seed data is intended to populate. For example, if you have a table named
customerin your database, your seed data file should be namedcustomer.csv,customer.json, orcustomer.ymldepending on the file format. - Column headers: Seed data files should contain column headers that match the column names of the table or view that the seed data is intended to populate. This ensures that the data is correctly mapped to the table or view columns.
- Seed data updates: When you make changes to the seed data files, you need to run the
dbt seedcommand to update the database with the new data. DBT uses a checksum to determine if the data has changed since the last time it was loaded, and if it has, DBT will reload the data. - Error messages: If the
seed-pathsconfiguration is set to an invalid directory path or the seed data files are not in the correct format, DBT will produce an error message indicating that the seed data files could not be loaded.
The seed-paths configuration in the dbt_project.yml file is an important component of a DBT project that specifies the directory or directories containing the seed data files. By following the guidelines for syntax, placement, file formats, file naming convention, and column headers, you can ensure that your seed data files are correctly loaded into the database and improve your DBT project workflow.
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