- 2015 Views
- 1 replies
- 1 kudos
Does running OPTIMIZE on a delta table destroy the transaction history of table?
If I run OPTIMIZE on a Delta Lake table, will it prevent me from time travelling to a version before OPTIMIZE was run?
- 2015 Views
- 1 replies
- 1 kudos
- 1 kudos
No, you will still be able to time travel to versions previous to the OPTIMIZE command. OPTIMIZE is just another transaction like MERGE, UPDATE, etc. Check out these docs to learn more about retention periods and the VACUUM command.
- 1 kudos
- 2439 Views
- 1 replies
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How do I find the users in workspaces
Looking to pull a list of all the users in their workspaces (including the ones who have never done anything), is there a way to do that? This for AWS
- 2439 Views
- 1 replies
- 0 kudos
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You can use the SKIM APIs. Endpoint: https://docs.databricks.com/dev-tools/api/latest/scim/scim-users.html#get-users Or you can use the Workspace API. The workspace API does not have a direct list users command, but you can use the workspace API to l...
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- 14230 Views
- 2 replies
- 4 kudos
Resolved! Max Columns for Delta table
Is there an upper limit/recommended max value for no. of columns for Delta table?
- 14230 Views
- 2 replies
- 4 kudos
- 4 kudos
Original answer posted by @Gray Gwizdz​ This was a fun question to try and find the answer to! Thank you for that I reviewed some of the most recent issues/bugs reported with Delta Lake and was able to find a similar issue where a user was running i...
- 4 kudos
- 2104 Views
- 0 replies
- 1 kudos
Databricks Autoloader Best practice
Databricks Autoloader is a popular mechanism for ingesting data/files from cloud storage into Delta; for a very high throughput source, what are the best practices to be following while scaling up an autoloader based pipeline to the tune of millions ...
- 2104 Views
- 0 replies
- 1 kudos
- 2371 Views
- 3 replies
- 0 kudos
Resolved! How to resuse Pandas code in PySpark?
I have single threaded Pandas code that is both not yet supported by Koalas nor easy to reimplement in PySpark. I would like to distribute this workload using Spark without rewriting all my Pandas code - is this possible?
- 2371 Views
- 3 replies
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This is for a specific scenario where the code is not yet supported by Koalas. One approach to consider is using a Pandas UDF, and splitting up the work in a way that allows your processing to move forward. This notebook is a great example of taking ...
- 0 kudos
- 8282 Views
- 2 replies
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Trigger.once mode recommendation
When is it recommended to use Trigger.once mode compared to fixed processing intervals with micro batches?
- 8282 Views
- 2 replies
- 0 kudos
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Also note, the configurations like maxFilesPerTrigger, maxBytesPerTrigger are ignored with Trigger.Once. Streaming queries with significantly less throughput can switch to Trigger.Once to avoid the continuous execution of the job checking the availab...
- 0 kudos
- 3476 Views
- 2 replies
- 0 kudos
VACUUM during read/write
Is it safe to run VACUUM on a Delta Lake table while data is being added to it at the same time? Will it impact the job result/performance?
- 3476 Views
- 2 replies
- 0 kudos
- 0 kudos
In the vast majority of cases, yes, it is safe to run VACUUM while data is concurrently being appended or updated to the same table. This is because VACUUM deletes data files no longer referenced by a Delta table's transaction log and does not effect...
- 0 kudos
- 3788 Views
- 2 replies
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How does running VACUUM on Delta Lake tables effect read/write performance?
If I don't run VACUUM on a Delta Lake table, will that make my read performance slower?
- 3788 Views
- 2 replies
- 0 kudos
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VACUUM has no effect on read/write performance to that table. Never running VACUUM on a table will not make read/write performance to a Delta Lake table any slower.If you run VACUUM very infrequently, your VACUUM runtimes themselves may be pretty hig...
- 0 kudos
- 1728 Views
- 1 replies
- 1 kudos
Can I have a Databricks Cluster that is only 1 node?
Yes you can create a "Single Node" Cluster, https://docs.databricks.com/clusters/single-node.html . It is currently not recommended to use "Single Node" cluster for streaming workloads
- 1728 Views
- 1 replies
- 1 kudos
- 1 kudos
Single Node clusters should not be used for production workloads involving streaming queries, or complex computations. The intention here is to bring up the Spark cluster for all kinds of workloads
- 1 kudos
- 1072 Views
- 1 replies
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- 1072 Views
- 1 replies
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Not yet but it is on the roadmap. Currently, only available in Databricks SQL
- 0 kudos
- 894 Views
- 0 replies
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- 894 Views
- 0 replies
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- 1568 Views
- 1 replies
- 1 kudos
- 1568 Views
- 1 replies
- 1 kudos
- 1 kudos
https://docs.databricks.com/dev-tools/api/latest/scim/scim-users.html#create-user
- 1 kudos
- 2717 Views
- 1 replies
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Resolved! What is the difference between spark.sessionState.catalog.listTables vs spark.catalog.listTables
I see a significant performance difference when calling spark.sessionState.catalog.list compared to spark.catalog.list. Is that expected?
- 2717 Views
- 1 replies
- 0 kudos
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spark.sessionState.catalog.listTables is a more lazy implementation.. it does not pull the column details when listing the tables. Hence it's faster. Whereas catalog.listTables will pull the column details as well. If the database has many Delta tabl...
- 0 kudos
- 6362 Views
- 1 replies
- 0 kudos
Resolved! How to list all Delta tables in a Database?
I wanted to get a list of all the Delta tables in a Database. What is the easiest way of getting it.
- 6362 Views
- 1 replies
- 0 kudos
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Below code, the snippet can be used to list down the tables in a databaseval db = "database_name" spark.sessionState.catalog.listTables(db).map(table=>spark.sessionState.catalog.externalCatalog.getTable(table.database.get,table.table)).filter(x=>x....
- 0 kudos
- 35587 Views
- 3 replies
- 1 kudos
- 35587 Views
- 3 replies
- 1 kudos
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This is by design and working as expected. Spark writes the data distributedly. use of coalesce (1) can help to generate one file, however this solution is not scalable for large data set as it involves bringing the data to one single task.
- 1 kudos
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