CSV

Read the files

read_csv(glob_paths)
read_csv(glob_paths, delimiter)
read_csv(glob_paths, delimiter, infer_records)

Beacon infers the schema from the file contents. The first row must be a header row.

• delimiter: the field separator, one character (default: ,)
• infer_records: the number of rows that Beacon samples for the column types (default: 128000)

SELECT * FROM read_csv('metadata/*.csv')

-- Tab-separated, sample 500 rows for type inference
SELECT * FROM read_csv(['data/*.tsv'], '\t', 500)

Inspect the schema

Check the columns and the types before you write a query:

SELECT * FROM read_csv('stations/*.csv') LIMIT 0;

Inspect a schema compares the _schema functions, SUMMARIZE, DESCRIBE and LIMIT 0, and says what each one costs.

Format details

• The first row must be a header row with the column names.
• A file must use UTF-8 encoding.
• Beacon infers the schema from the file contents.

As an external table

CREATE EXTERNAL TABLE station_metadata
STORED AS CSV
LOCATION 'metadata/stations/'

See Create External Tables for the full DDL. See Data Sources for the full read model.