Add a median measure

[toohsk]

Description & motivation

Hi @stumelius,

I would like to add a median measurement in profiler because it would be a good indicator when you want to know the skewness simply.
Feel free to discard the PR if you think it not so useful.

Checklist

• [x] I have verified that these changes work locally on the following warehouses (Note: it's okay if you do not have access to all warehouses, this helps us understand what has been covered):
  • [x] Postgres
  • [x] BigQuery
  • [ ] Snowflake
  • [ ] Redshift
  • [ ] SQL Server
  • [ ] Databricks
• [x] I have written tests for new macros (either as dbt schema tests in integration_tests/models, dbt data tests in integration_tests/tests or integration tests in the CI workflow)
• [x] I have updated the README.md (if applicable)

[stumelius]

@toohsk The code looks good, great work! There are errors when running the models in BigQuery:

12:30:32  Database Error in model profile (models/profile.sql)
12:30:32    SELECT list expression references column id which is neither grouped nor aggregated at [36:27]

To me it looks like the issue is with using the percentile_dict window function in a group by select statement. What do you think?

[toohsk]

@stumelius Thanks for checking this PR 😄 ! I hadn't tested BigQuery, so I didn't realize this error, but it seems you're right. I fixed the query for bigquery so could you run it on my behalf?

[stumelius]

@toohsk All the automated tests are now passing. Well done and thanks for your contribution @toohsk :) Merging this now

[stumelius]

@toohsk Here's the release https://github.com/data-mie/dbt-profiler/releases/tag/0.7.0

[toohsk]

Thank you so much @stumelius ! I'm happy to have contributed to this project.