e.g. https://druid.apache.org/docs/latest/querying/sql-array-functions.html does not have Array_Agg

can you share the query you were trying to run?

CASE WHEN CAST(ARRAY_QUANTILE(ARRAY_AGG( OURCOLUMN, 500000), 0.10) AS BIGINT) = 'NaN' THEN NULL ELSE ARRAY_QUANTILE(ARRAY_AGG(OURCOLUMN, 500000), 0.10) END ) AS "OURCOLUMN_10_percentile"

This is the query we're trying now, and we're getting 504 (timeout) errors

Regarding the documentation...I feel kinda dumb! I looked into the Array Functions for...an array function...which I thought was where it would go! Thanks for finding the relevant information for me @Gian Merlino and @Hellmar Becker

I think I have found a solution! Since we're calculating what value is for a ranked percentile, the distinct values are what matter--not the frequency of the values. Thus, if I use the

ARRAY_AGG(DISTINCT expr, [size])

then the query returns a value without a 504 timeout. I'll report back with any updates, but for now this seems to be resolved!

about the docs, yeah, it would make sense for us to link from 'array functions' to the aggregate section too