Preview random rows of Parquet data in place from external object store using a foreign table:
The examples use a sample river flow data set. To use your own data, replace the table and column names, and authorization object. See Variable Substitutions for Examples for the credentials and location values for the sample data set.
- To run NOS-related commands, log on to the database as a user with the required privileges.
- If it does not exist, create the foreign table or ask your database administrator to create the foreign table called riverflow_parquet. See Setting Up to Run Parquet Examples.
To see sample records with the column names included before each string of values, issue the following command against the foreign table called riverflow_parquet:
SELECT TOP 2 * FROM riverflow_parquet;
Your result will be similar to this, reflecting your external object store location:
Location /S3/td-usgs.s3.amazonaws.com/PARQUETDATA/09394500/2018/07/01.parquet GageHeight2 4.81 Flow 0.00 site_no 9394500 datetime 2018-07-01 00:15 Precipitation 0.00 GageHeight 4.75 Location /S3/td-usgs.s3.amazonaws.com/PARQUETDATA/09394500/2018/07/01.parquet GageHeight2 4.82 Flow 0.01 site_no 9394500 datetime 2018-07-01 00:00 Precipitation 0.00 GageHeight 4.75For readability, the output is displayed vertically.