add data type and time zone considerations #6335
Open
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Adding clarifying information about time zones and data types per [internal slack thread](https://dbt-labs.slack.com/archives/C03KHQRQUBX/p1729278831684459?thread_ts=1729023422.431269&cid=C03KHQRQUBX)
github-actions
bot
added
content
|
The latest updates on your projects. Learn more about Vercel for Git ↗︎
|
mirnawong1
commented
Oct 22, 2024
mirnawong1
commented
Oct 22, 2024
courtneyholcomb
approved these changes
Oct 22, 2024
|
|
||
| - Consistent data types — Both your dimension column and the time spine column should use the same data type to allow accurate comparisons. Functions like `DATE_TRUNC` don't change the data type of the input in some databases (like Snowflake). Using different data types can lead to mismatches and inaccurate results. | ||
|
|
||
| We recommend using `DATETIME` or `TIMESTAMP` data types for your time dimensions and time spine, as they support all granularities. The `DATE` data type may not support higher granularities like hours or minutes. |
There was a problem hiding this comment.
nit: higher -> smaller
|
|
||
| We recommend using `DATETIME` or `TIMESTAMP` data types for your time dimensions and time spine, as they support all granularities. The `DATE` data type may not support higher granularities like hours or minutes. | ||
|
|
||
| - Consistent time zones — Ensure that all your time-related data uses the same time zone. MetricFlow supports UTC and currently doesn't perform any timezone manipulation. This means inconsistent time zones can cause unexpected results during aggregations and comparisons. |
There was a problem hiding this comment.
I would change this section slightly:
Time zones — MetricFlow currently doesn't perform any timezone manipulation. When working with timezone-aware data, inconsistent time zones may lead to unexpected results during aggregations and comparisons.
Reasons for the change:
- MF doesn't support UTC per se, it just ignores timezones entirely. UTC is just the most common way that people are likely to store their data for timezone consistency.
- I don't think we should ask them to ensure all their data uses the same timezone since they might have a valid reason for not doing that. We just want to warn them that there might be weird interactions in that case.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Adding clarifying information about time zones and data types per internal slack thread
🚀 Deployment available! Here are the direct links to the updated files: