Using Flex slots

[kk2die4]

Hello

I have a query that breaks with a "billing tier exceeded" error in BigQuery. It processes a very small amount of data,  but is very computationally intensive.

I am currently on an on-demand pricing rate. If I were to buy say 2000 slots : 

1. Will my query use all the 2000(on demand) + 2000 (flex) whilst running or just the 2000 ? 

2. If I were to use the flex slots, will the CPU minutes cap go away ?

Thank you.

[nwipfli]

Hello,

If you make a slot commitment with flex slots, you then assign these slots to a reservation which can have projects to it. In that case, these projects will only use your flex slot and no on-demand slots.

Not all the 2000 flex slots might be consumed for your query. It really depends on the complexity of your query, you need to test and monitor.

What CPU minutes cap are you talking about ?
With flex slots (which is part of the flat rate), you only pay for the slots you reserved. And BigQuery uses part or all these slots (depending on the query).

Regards
Nicolas

[kk2die4]

Hi Nicholas,

Thank you for your response.

My error looks like this : 

Query exceeded resource limits. This query used 33819 CPU seconds but would charge only 114M Analysis bytes. This exceeds the ratio supported by the on-demand pricing model. Please consider moving this workload to the flat-rate reservation pricing model, which does not have this limit. 33819 CPU seconds were used, and this query must use less than 29100 CPU seconds.

Sorry it was CPU seconds. If I were to buy flex slots, would this CPU limit go away ?

Also, the documentation does not talk about the relationship between the number of CPU seconds and the slots. So, how many CPU seconds would be, say , 100 slots ?

Thank you. 

[nwipfli · Accepted solution]

Hello,

The error states the following:

"Please consider moving this workload to the flat-rate reservation pricing model, which does not have this limit"

Flat-rate includes the following options (see here) :

• Monthly flat-rate
• Annual flat-rate
• Flex slots

Therefore, flex slots are not affected by this limit.

Regards
Nicolas

[kk2die4]

Thank you.