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_path. See: Filtering External Parquet Data From a Foreign Table.
Combine path and column filtering (GageHeight > 5) to find how many times the gauge height was greater than 5 in July 2018 at river site 09394500:
SELECT COUNT(*) FROM riverflow_parquet_path WHERE GageHeight > 5 AND $path.$siteno = 09394500 AND $path.$year = '2018' AND $path.$month = '07';
Count(*) -------- 834