A table contains a timestamp representing the date and time that a write occurred to a column.
Using the WRITETIME function in a SELECT statement returns the timestamp that the column was written to the YugabyteDB database.
The output of the function is microseconds.
Example:
[root@localhost ~]# ycqlsh -u cassandra
cassandra@ycqlsh> CREATE TABLE test.stuff(c1 INT PRIMARY KEY, c2 TIMESTAMP);
cassandra@ycqlsh> INSERT INTO test.stuff (c1, c2) VALUES (1, currenttimestamp());
cassandra@ycqlsh> SELECT c2, writetime(c2) FROM test.stuff;
c2 | writetime(c2)
---------------------------------+------------------
2022-10-03 19:45:17.175000+0000 | 1664826317176027
(1 rows)
The timestamp we get is actually the number of microseconds since midnight on January 1, 1970.
What if you wanted to see that converted to a human readable format?
We could use a Linux command like this…
[root@localhost ~]# date +"%m/%d/%Y %I:%M:%S.%N" -d @`echo "1664826317176027/1000000" | bc -l`
10/03/2022 07:45:17.176027000
Or we can make use of YugabyteDB’s other API, YSQL!
[root@localhost ~]# ysqlsh -c "SELECT TO_TIMESTAMP(1664826317176027 / 1000000.000)::TIMESTAMP WITH TIME ZONE;"
to_timestamp
-------------------------------
2022-10-03 19:45:17.176027+00
(1 row)
Have Fun!