topic Re: Delta Optimistic Transactions Resolution and Exceptions in Data Engineering

Delta Optimistic Transactions Resolution and Exceptions

User16783853501 — Thu, 24 Jun 2021 01:55:35 GMT

What is the best way to deal with concurrent exceptions in Delta when you have multiple writers on the same delta table ?

Re: Delta Optimistic Transactions Resolution and Exceptions

aladda — Thu, 24 Jun 2021 03:08:17 GMT

Delta operations that can result in a conflict with multiple writers can be found here - https://docs.databricks.com/delta/concurrency-control.html#write-conflicts.In all cases marked “can conflict”, whether the two operations will conflict depends on whether they operate on the same set of files. You can make the two sets of files disjoint by partitioning the table by the same columns as those used in the conditions of the operations

As a general rule the ideas would be the defined your predicates in such a way that concurrent writers operate on different partitions/files of a delta table to avoid concurrent write exceptions

Re: Delta Optimistic Transactions Resolution and Exceptions

sajith_appukutt — Thu, 24 Jun 2021 04:22:18 GMT

While you can try-catch-retry , it would be expensive to retry as the underlying table snapshot would have changed. So the best approach is to avoid conflicts using partitioning and disjoint command conditions as much as possible.