Tableau Output error - date field causes output to hang

Question

Hi everyone - I've recently come across an issue when attempting to update an existing tableau datasource when adding a new date field. I'm not sure if it's a known problem, but it's the first time I've encountered it. I'm using Designer 2024.1.1.209 Patch: 7 with Tableau Tools v1.5.2.

Adding a new date field from a salesforce input to my workflow (which, given that it is new to the salesforce object is almost entirely populated with NULL) causes my tableau output to fail - it just hangs forever and fails to complete. There's approx. 3.1m records in the data - so it's not a huge dataset but it's big enough.

De-selecting the field from the output resolves the problem. Overwriting the NULL date values with a dummy date also resolves the issue. Outputting the date field as a string resolves the problem - but that's not what I need. I need a fix, and when I add further new date fields I don't want a repeat of the same issue (I have more new date fields to add to the workflow).

I've tried lots of resolutions:

* deleting and re-adding a new tableau output tool
* copying the entire workflow to a new file
* clearing all caches
* outputting to a local hyper has the same issue
* adding a dummy record with populated default date values as the first record in the data in case there's some internal type sampling going on
* adding 5k dummy records to the start of the data set in case the sampling is proportionately based
* forced date field typing
* forcing date > string > date type coercion
* adding a formula field and creating a secondary date field from within the workflow (i.e. not sourced from Salesforce) presents the same error.
* uninstalling/reinstalling the output tools.
* creating a new tableau datasource doesn't fix it
* switching to datetime doesn't fix it.

I'm now kinda stuck and mostly out of ideas except using string outputs. I'd appreciate any other suggestions that I've not yet tried or just confirmation that I'm not as dumb as a bag of rocks and I've missed something super simple.

Thanks in advance!

leehinchcliffe · Answer

Hi Rhys - apologies for the long delay for this reply...unfortunately, your proposed solution didn't work - I'm not sure that any "proper" proposal would to be honest. But on carried on testing idea after idea.

I have found a further workaround without being able to understand further what the underlying issue is.

I've discovered that placing the following tools in this sequence - before my tableau output tool - sidesteps the issue (or at least I can output with no errors):
1) use a multi field formula tool to force all date fields to strings and cast them back again to dates YYYY-MM-DD and force the output type to date;
2) immediately follow that multi-field tool with a select tool and ensure that all the date fields are defined as date (10);
3) immediately follow that select tool with a second select tool and ensure that all the date fields are again defined as date (10);
4) finally, output to tableau

It seems there's some internal typing going on that,  I would imagine, when using multiple select tools in sequence forces output types in a way that a single tool doesn't. Otherwise, I'm at a loss as to any rational explanation.

¯\_(ツ)_/¯

Many thanks for your input!

Rhys_Cooper · Answer

No problemo @leehinchcliffe let me know if works.

leehinchcliffe · Answer

Thanks Rhys - I'll give that a whirl.