Hi,there.
Recently,I want to run a query in bigquery web UI by using "group by" over some tables(tables' name suits xxx_mst_yyyymmdd).The rows will be over 10 million. Unhappily,the query failed with this error:
Query Failed
Error: Resources exceeded during query execution.
I did some improvements with my query language,the error may not happen for this time.But with the increasement of my data, the Error will also appear in the future.So I checked the latest release of Bigquery,maybe there two ways to solve this:
1.After 2016/01/01,Bigquery will change the Query pricing tiers to satisfy the "High Compute Tiers" so that the "resourcesExceeded error" will not happen again.
2.BigQuery Slots.
I checked some documents in Google and didn't find a way on how to use BigQuery Slots.Is there any sample or usecase of BigQuery Slots?Or I have to contact with BigQuery Team to open the function?
Hope someone can help me to answer this question,thanks very much!
A couple of points:
I'm surprised that a GROUP BY with a cardinality of 10M failed with resources exceeded. Can you provide a job id of the failed query so we can investigate? You mention that you're concerned about hitting these errors more often as your data size increases; you should likely be able to increase your data size by a few more orders of magnitude without seeing this; likely you've encountered either a bug or something was strange with either your query or your data.
"High Compute Tiers" won't necessarily get rid of resourcesExceeded. For the most part, resourcesExceeded means that BigQuery ran into memory limitations; high compute tiers only address CPU usage. (and note, they haven't been enabled yet).
BigQuery slots enable you to process data faster and with more reliable performance. For the most part, they also wouldn't help prevent resourcesExceeded errors.
There is currently (as of Nov 5) a bug where you may need to provide an EACH keyword with a GROUP BY. Recent changes should enable BigQuery to automatically select the execution strategy, so EACH shouldn't be needed, but there are a couple of cases where it doesn't pick the right one. When in doubt, add an EACH to your JOIN and GROUP BY operations.
To get your project eligible for using slots you need to contact support.
Related
I noticed that running a SELECT count(*) FROM myTable on my larger BQ tables yields long running times, upwards of 30/40 seconds despite the validator claiming the query processes 0 bytes. This doesn't seem quite right when 500 GB queries run faster. Additionally, total row counts are listed under details -> Table Info. Am I doing something wrong? Is there a way to get total row counts instantly?
When you run a count BigQuery still needs to allocate resources (such as: slot units, shards etc). You might be reaching some limits which cause a delay. For example, the slots default per project is 2,000 units.
BigQuery execution plan provides very detail information about the process which can help you better understand the source of the delay.
One way to overcome this is to use an approximate method described in this link
This Slide by Google might also help you
For more details see this video about how to understand the execution plan
I would like to know how to increase my billing tier for only one Bigquery query in Redash (not the whole project).
I am getting this error, while trying to refresh the query in Redash:
"Error running query: Query exceeded resource limits for tier 1. Tier 29 or higher required".
According to Bigquery's documentation there are three ways to increase this limit (https://cloud.google.com/bigquery/pricing#high-compute). However, I am not sure which one is applicable to the queries that are written directly in the Redash's query editor. It would be great if you could provide an example.
Thanks for your help.
I'm trying to run a pretty simple query but it's failing with an Resources exceeded error.
I read in another post that the heuristic used to allocate the number of mixers could fail from time to time.
SELECT
response.auctionId,
response.scenarioId,
ARRAY_AGG(response) AS responses
FROM
rtb_response_logs.2016080515
GROUP BY
response.auctionId,
response.scenarioId
Is there a way to fix my query knowing that:
a response is composed of 38 fields (most of them being short strings)
the max(count()) of a single response is kind of low (165)
Query Failed
Error: Resources exceeded during query execution.
Job ID: teads-1307:bquijob_257ce97b_1566a6a3f27
It's a current limitation that arrays (produced by ARRAY_AGG or other means) must fit in the memory of a single machine. We've made a couple of recent improvements that should help to reduce the resources required for queries such as this, however. To confirm whether this is the issue, you could try a query such as:
SELECT
SUM(LENGTH(FORMAT("%t", response))) AS total_response_size
FROM
rtb_response_logs.2016080515
GROUP BY
response.auctionId,
response.scenarioId
ORDER BY total_response_size DESC LIMIT 1;
This formats the structs as strings as a rough heuristic of how much memory they would take to represent. If the result is very large, then perhaps we can restructure the query to use less memory. If the result is not very large, then some other issue is at play, and we'll look into getting it fixed :) Thanks!
This query runs fails with resources exceeded:
SELECT
*,
DAY(event_timestamp) as whywontitwork,
FROM
looker_scratch.LR_78W8A60O4MQ20L2U6OA5B_events_sql_doctor_activity
But this one works fine:
SELECT
*
FROM
looker_scratch.LR_78W8A60O4MQ20L2U6OA5B_events_sql_doctor_activity
The source table is 14m rows but I've run similar queries on much larger datasets before. We have large results enabled and have tried both flattened results and not (though there are no nested fields anyway). The error also occurs if you use the DATE() function instead of DAY(), or a REGEXP_EXTRACT() function
The job id is realself-main:bquijob_69e3a888_152f1fdc205.
You've hit an internal error in BigQuery. We tweaked our query engine's configuration at around 3pm (US Pacific Time) in an effort to prevent the error.
Update: After observing the error rate, it looks like this change has fixed the problem. If you see any other issues, please let us know. Note that StackOverflow is best for usage questions, but if you suspect a bug, you can file an issue at our public issue tracker.
I would like to receive a notification, ideally via email, when some threshold is met in Google BigQuery. For example, if the query is:
SELECT name, count(id) FROM terrible_things
WHERE date(terrible_thing) < -1d
Then I would want to get an alert when there were greater than 0 results, and I would want that alert to contain the name of each object and how many there were.
BigQuery does not provide the kinds of services you'd need to build this without involving other technologies. However, you should be able to use something like appengine (which does have a task scheduling mechanism) to periodically issue your monitoring query probe, check the results of the job, and alert if there are nonzero rows in the results. Alternately, you could do this locally using some scripting and leveraging the BQ command line tool.
You could also refine things by using BQ's table decorators to only scan the data that's arrived since you last ran your monitoring query, if you retain knowledge of the last probe's execution in the calling system.
In short: Something else needs to issue the queries and react based on the outcome, but BQ can certainly evaluate the data.