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)