Determining time-to-live for a column

Steps for creating a table, inserting data into two columns, and calling the TTL function to retrieve the date/time of the writes to the columns.

This procedure creates a table, inserts data into two columns, and calls the TTL function to retrieve the date/time of the writes to the columns.

Procedure

Create a users table named clicks in the excelsior keyspace.

CREATE TABLE excelsior.clicks (
  userid uuid,
  url text,
  date timestamp,  //unrelated to WRITETIME discussed in the next section
  name text,
  PRIMARY KEY (userid, url)
);

Insert data into the table, including a date in yyyy-mm-dd format, and set that data to expire in a day (86400 seconds). Use the USING TTL clause to set the expiration period.
```
INSERT INTO excelsior.clicks (
  userid, url, date, name)
  VALUES (
    3715e600-2eb0-11e2-81c1-0800200c9a66,
    'http://apache.org',
    '2013-10-09', 'Mary')
    USING TTL 86400;
```
Wait for a while and then issue a SELECT statement to determine how much longer the data entered in step 2 has to live.
```
SELECT TTL (name) from excelsior.clicks
  WHERE url = 'http://apache.org' ALLOW FILTERING;
```
Output is, for example, 85908 seconds:
```
 ttl(name)
-----------
 85908
                    
(1 rows)
```