Example:
dbadmin=> SELECT *
dbadmin-> FROM (SELECT "HOUR", "Total IO (GB)", "Read IO (GB)", "Write IO (GB)"
dbadmin(> FROM (SELECT MIN(TRUNC(start_time)) start_time,
dbadmin(> DATE_TRUNC('hour', start_time) as "HOUR",
dbadmin(> (SUM(read_kbytes_per_sec) + SUM(written_kbytes_per_sec)) * 60/1024/1024 as "Total IO (GB)",
dbadmin(> SUM(read_kbytes_per_sec) * 60/1024/1024 as "Read IO (GB)",
dbadmin(> SUM(written_kbytes_per_sec) * 60/1024/1024 as "Write IO (GB)"
dbadmin(> FROM v_monitor.io_usage
dbadmin(> GROUP BY 2) foo
dbadmin(> WHERE start_time >= TRUNC(SYSDATE) - 5 -- LAST 5 DAYS!
dbadmin(> LIMIT 1 OVER (PARTITION BY start_time ORDER BY start_time, "Total IO (GB)" DESC)) foo2
dbadmin-> ORDER BY "HOUR" DESC;
HOUR | Total IO (GB) | Read IO (GB) | Write IO (GB)
---------------------+------------------+---------------------+------------------
2019-08-02 10:00:00 | 7.31542510986328 | 1.28464279174805 | 6.03078231811523
2019-08-01 23:00:00 | 13.6195484161377 | 10.5460218429565 | 3.07352657318115
2019-07-31 23:00:00 | 13.6010026931763 | 10.5195688247681 | 3.0814338684082
2019-07-30 12:00:00 | 104.669023132324 | 6.8077428817749 | 97.8612802505493
2019-07-29 14:00:00 | 1.92557315826416 | 0.00724811553955078 | 1.91832504272461
(5 rows)
Helpful Link:
https://www.vertica.com/docs/latest/HTML/Content/Authoring/SQLReferenceManual/SystemTables/MONITOR/IO_USAGE.htmHave fun!
About the Author
James Knicely
Vertica Field Chief Technologist
I've had the privilege of working with many database technologies in my career. But after being introduced to Vertica in May of 2011 as a client, I was hooked on the new technology after witnessing a query run in milliseconds that had previously ran for hours on the legacy database we had in place. It was then that I knew I wanted to eventually join the Vertica team, and 4 years later I did! I am currently a Vertica evangelist and am ready to help you get on board! Please feel free to reach out to me with any questions you have about Vertica and make sure to follow my Vertica Quick Tips!
