How do I display the query time when a query completes in Vertica? - sql

Question

When using vsql, I would like to see how long a query took to run once it completes. For example when i run:
select count(distinct key) from schema.table;
I would like to see an output like:
5678
(1 row)
total query time: 55 seconds.
If this is not possible, is there another way to measure query time?

Answer 1

In vsql type:
\timing
and then hit Enter. You'll like what you'll see :-)
Repeating that will turn it off.

Answer 2

Regarding the other part of your question:
is there another way to measure query time?
Vertica can log a history of all queries executed on the cluster which is another source of query time. Before 6.0 the relevant system table was QUERY_REPO, starting with 6.0 it is QUERY_REQUESTS.
Assuming you're on 6.0 or higher, QUERY_REQUESTS.REQUEST_DURATION_MS will give you the query duration in milliseconds.
Example of how you might use QUERY_REQUESTS:
select *
from query_requests
where request_type = 'QUERY'
and user_name = 'dbadmin'
and start_timestamp >= CURRENT_DATE
and request ilike 'select%from%schema.table%'
order by start_timestamp;
The QUERY_PROFILES.QUERY_DURATION_US and RESOURCE_ACQUISITIONS.DURATION_MS columns may also be of interest to you. Here are the short descriptions of those tables in case you're not already familiar:
RESOURCE_ACQUISITIONS - Retains information about resources (memory, open file handles, threads) acquired by each running request for each resource pool in the system.
QUERY_PROFILES - Provides information about queries that have run.

Answer 3

I'm not sure how to enable that in vsql or if that's possible. But you could get that information from a script.
Here's the psuedocode (I used to use perl):
print time
system("vsql -c 'select * from table'");
print time
Or put time into a variable and do some subtraction.
The other option is to use some tool like Toad to connect to Vertica instead of using vsql.