Is it reasonable for the process "Determining the location of DBIO file fragments." to take me 7 hours?

[Dicer]

I only have 1000 columns. Each column has 252 rows, so there are only 252000 data points.

How come it can route tasks for the best-cached locality for 7 hours?

[Kaniz]

Hi @Cheuk Hin Christophe Poon​, Can you please run this command and check again?

%sql Optimize [table name]

[Dicer]

I tried the following one and it still took more than 10 hours until Fatal error: The Python kernel is unresponsive.

%sql
 
--Enable Auto Optimization
set spark.databricks.delta.properties.defaults.autoOptimize.optimizeWrite = true;
set spark.databricks.delta.properties.defaults.autoOptimize.autoCompact = true;

[Dicer]

@Kaniz Fatma​ Is there any way to shorten the process "Determining the location of DBIO file fragments." runtime?

[Anonymous]

Hi @Cheuk Hin Christophe Poon​ 

Hope all is well! Just wanted to check in if you were able to resolve your issue and would you be happy to share the solution or mark an answer as best? Else please let us know if you need more help. 

We'd love to hear from you.

Thanks!

[Noopur_Nigam]

Hi @Cheuk Hin Christophe Poon​ have you optimize your table anytime since it's creation? If not, then optimize may take some time depending on the no of underlying files.

Please try to run optimize manually as described in below document:

https://docs.databricks.com/sql/language-manual/delta-optimize.html

If this doesn't help, you can try disabling DBIO cache by setting below in your notebook:

spark.conf.set("spark.databricks.io.cache.enabled", "false")