In this section, we will analyze the performance of the system using SQL query commands. The use of Amazon Athena will be charged when we query, based on the amount of data scanned (scan) which is data recorded monthly and files in parquet format. This data has been compressed and fragmented to minimize costs when using Amazon Athena. However, when querying, you should still limit the number of records returned with the LIMIT keyword at the end of the statement.
SQL SELECT statement : SELECT is used to select data from a database. The data returned is stored in a result table.
SQL SELECT DISTINCT statement: SELECT DISTINCT is used to return distinct (different) values. Inside a table, a column often contains many duplicate values; and sometimes you only want to list the different (distinct) values.
WHERE clause in SQL: The WHERE clause is used to filter records. It is used to extract only those records that fulfill a specified condition.
SQL GROUP BY statement: GROUP BY is used to group rows that have the same values into summary rows.
SQL ORDER BY statement: ORDER BY is used to sort the result-set in ascending or descending order.
SQL LIKE operator: The LIKE operator is used in a WHERE clause to search for a specified pattern in a column.
LIMIT keyword: limits the number of records returned