A data analyst wants to retrieve only records from a database that have matching values in two different tables. Which JOIN function should they use?

The data analyst should use the INNER JOIN function to retrieve only records that have matching values in two different tables. Here are the steps:

1. Identify the two tables you want to join. Let's call them Table1 and Table2.

2. Determine the common field between the two tables. This is the field that contains the matching values. Let's call this field 'CommonField'.

3. Use the INNER JOIN function in your SQL query. The basic syntax is as follows:

   SELECT column_name(s) FROM Table1 INNER JOIN Table2 ON Table1.CommonField = Table2.CommonField;

4. Run the query. The result will be a new table that includes only the records from Table1 and Table2 where the value in 'CommonField' is the same in both tables.

Remember, INNER JOIN returns rows from both tables where there is a match. If there is no match, the result is NULL.