Is there a way to get and store the execution time of a select?
select * from table1
Thank you,
Radu.
Oracle provides TIMING command to check the execution time taken for a query.
http://infolab.stanford.edu/~ullman/fcdb/oracle/or-nonstandard.html#timing%20sql%20commands
Tom Kyte has developed a pretty simple test harness called runstats that gives you great timing information.
All SQL statements are stored in V$SQL, but they will age out eventually. ELAPSED_TIME/EXECUTIONS will get you the average time to run the query.
Related
I have a sql file running many queries. I want to see the accumualted sum of all queries. I know that if I turn on timing, or call
\timing
query 1;
query 2;
query 3;
...
query n;
at the beginning of the script, it will start to show time it takes for each query to run. However, I need to have the accumulate results of all queries, without having to manually add them.
Is there a systematic way? If not, how can I fetch the interim times to throw them in a variable.
The pg_stat_statements is a good module that provides a means for tracking execution statistics.
First, add pg_stat_statements to shared_preload_libraries in the
postgresql.conf file. To know where this .conf file exists in your
filesystem, run show config_file;
shared_preload_libraries = 'pg_stat_statements'
Restart Postgres database
Create the extension
CREATE EXTENSION pg_stat_statements;
Now, the module provides a View, pg_stat_statements, which helps you to analyze various query execution metrics.
Reset the contents of stat collected before running queries.
SELECT pg_stat_statements_reset();
Now, execute your script file containing queries.
\i script_file.sql
You may get all the timing statistics of all the queries executed. To get the total time taken, simply run
select sum(total_time) from pg_stat_statements
where query !~* 'pg_stat_statements';
The time you get is in milliseconds, which may be converted to desired format using various timestamp related Postgres functions
If you want to time the whole script, on linux or mac you can use the time utility to launch the script.
The measurement in this case is a bit more than the sum of the raw query times, because it includes some overhead of starting and running the psql command. On my system this overhead is around 20ms.
$ time psql < script.sql
…
real 0m0.117s
user 0m0.008s
sys 0m0.007s
The real value is the time it took to execute the whole script, including the aforementioned overhead.
The approach in this answer is a crude, simple client side way to measure the runtime of the overall script. It is not useful to measure milli-second precision server side execution times. It still might be sufficient for many use-cases.
The solution of Kaushik Nayak is a way more precise method to time executions directly on the server. It also provides much more insight into the execution (eg. query level times).
I need to measure the execution time in a query in the ALTIBASE DBMS.
For example, I need to now in ms the time it took a SELECT * FROM example;
I tried to use the methods that have some traditional DBMS like MySQL or Oracle and doesn't work.
There are some method. The first one you can use the log from altibase to analyze. And the other method is to coding some program that recording time from using the SELECT to get result. Now, I also learn to use altibase - We can together.
I found the solution
After entering to the client with next command isql -u sys -p manager -sysdba you need to execute the next query
SET TIMING ON;
Next the following queries will have the execution time.
I want to get the query plan in Exasol database to check the total execution time, memory and cpu usage. Profiling in Exasol is so complex and difficult to understand.
Is there any way to get the query plan like explain analyze in PostgreSQL or any other simple way?
Please explain how to read the query plan in Exasol without executing the query?
You can check the EXASOL User Manual about profiling a query. I agree it's a bit cumbersome :)
Or you can use the scripts I wrote to have an explain like command: exasol-explain
Maybe it will be useful for someone who will try to use EXASOL Explain. There is a script with one missed field in select statement in exasol-explain/scripts/sqlprofile.lua, after temp_db_ram_peak field should follow:
max(PERSISTENT_DB_RAM_PEAK) as PERSISTENT_DB_RAM_PEAK
Otherwise "explain" and "explain_this" return an error "incorrect numbers of result column"
I'm making an ETL using Talend, which should permit to create an Excel file with some informations resulting from a tNetezzaInput component in Talend, executing a dynamic query.
It works perfectly. However, some queries finish after 2 hours, depending of the table size ( I have more than 1000 queries to execute ).
I would like to set a timeout (30seconds/1 minute) on my tNetezzaInput.
Is that possible?
Thank you
Not sure about Talend/tNetezzaInput. But you can address this issue at Netezza side using query timeout limits along with runaway query event.
Secondly, how big tables are that query taking 2 hours. Hope its not some query/join issue.
Thanks,
Sanjit
A query on 200 millions records with 100+ columns tables should not take 2 hrs, unless there is some issue with data distribution, join, statistics or workload manager.
Have you checked the pg, dbos logs, planfile about this query?
Thanks,
Sanjit
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?
In vsql type:
\timing
and then hit Enter. You'll like what you'll see :-)
Repeating that will turn it off.
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.
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.