On May 7, 2024, we will push a change to Qlik Cloud Analytics that will add a new safeguard for apps containing section access tables.
Background:
It is currently possible to specify up to 1 000 000 distinct values per user for the reduction and OMIT fields. After reaching 1 000 000, the table is truncated.
As of now, there is no indication that the truncation happened. Users might make business decisions based on an incomplete or incorrect set of data without realising that. This a rare scenario, given the large number of values, but we want to prevent this from happening.
What will change?
During the reload of apps, we will execute an additional Section Access evaluation: if the number of distinct values in either the OMIT or any reduction field per table exceeds the number of 1 000 000, the reload will fail. Currently reloads are succeeding without any indication of the truncation.
Why the change?
This is a safeguard to prevent users from getting a truncated section access table when viewing the data, preventing them from seeing too much, or too little.
How can we recognise Section Access evaluation from standard reload failures?
Errors related to Section Access evaluation failures will look like this:
Error during section access evaluation. Field (NAME_OF_THE_FIELD) contains 1000002 unique values. Max allowed is 1000000 unique values.
Is the new safeguard stricter than before?
Yes. The new safeguard is stricter: 1 000 000 unique values per table as opposed to the 1 000 000 unique values per user of the standard Section Access limitation.
There are reasons for this: adding per-user evaluation would cause a performance impact on reloads, and having stricter safeguard will allow administrators to keep an eye on apps that are at risk of showing an incorrect set of data.
Will some of the reloads that are currently safe within the limit fail?
Yes. Because of the stricter guardrail, a very limited set of reloads that are currently showing data as expected will fail. Qlik Support will reach out via proactive cases to customers who are currently in that scenario according to our logs. However, we encourage every customer to review section access tables with a large number of values that are currently at risk of being truncated.
Can we go back to the old behaviour?
Yes. To disable this evaluation in a particular script, add “SET EnableSectionAccessEvaluation = 0”; to the script. This variable can already be added before the change is in place, without impact on current reloads. Adding the variable will revert to the old behaviour, where reloads succeed ad section access distinct values are truncated after the limit of 1 000 000 per user.
Note: Disabling this evaluation carries the risk of getting a truncated section access table for particular users after a reload, which is what we aim to avoid with the new safeguard.
Daniele - Principal Technical Support Engineer & SaaS Support Coordinator at Qlik
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