How come MySQL does not support window function, specifically lag in dataflows?

user084060 · February 2021

Hi,

I am currently building a dataflow and trying to get the best out of both sql dialect. I use Mysql to order my data (because redshift doesnt order properly) and then use another datflow in the redshift dialect to be able to use window function. What I am curious about is to know why Mysql does not support window function, specifically lag in dataflows? I have been googling and it seems that you are suppose to be able to use window functions with mysql: https://dev.mysql.com/doc/refman/8.0/en/window-function-descriptions.html

but why is it not possible in Domo?

Thank you

GrantSmith · February 2021

Hi @user084060

This is because the MySQL backend in Domo is based on MySQL 5.6 which doesn't have window functions. They were later added with MySQL 8.0.

I'd recommend you look into Magic ETL 2.0 which has a Rank & Window tile which you can use LAG functions and is typically much more performant than MySQL / Redshift if at all possible.

jaeW_at_Onyx · February 2021

+1 on @GrantSmith, use Magic 2.0 it'll be much easier and faster over large datasets.

But if you're hell bent on it, you can use variables.

SELECT col, day
       @running_total:=@running_total + amount as running_total
FROM
table t, (SELECT @running_total:=0) r
ORDER BY t.day;

https://popsql.com/learn-sql/mysql/how-to-calculate-cumulative-sum-running-total-in-mysql

mfed303 · April 18

Is there any word that DOMO has updated their mysql to 8.0? I'd like to use it in an adrenaline sql statement.

jaeW_at_Onyx · April 29

@mfed303 it probably won't happen. Domo are pushing more SQL functionality into MagicETL, which will be a much stronger push to making MySQL ETLs obsolete

https://www.youtube.com/watch?v=W4RLRyxnQ1o&pp=ygUWZG9tbyBtYWdpY2V0bCBkYXRhY3Jldw%3D%3D

How come MySQL does not support window function, specifically lag in dataflows?

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