topic Question regarding ZORDER option of OPTIMIZE in Data Engineering

Question regarding ZORDER option of OPTIMIZE

leos1 — Thu, 13 Oct 2022 10:48:17 GMT

Is the order of the columns in ZORDER important? For example, does ZORDER BY (product, site) and ZORDER BY (site, product) produce the same results?

Re: Question regarding ZORDER option of OPTIMIZE

-werners- — Thu, 13 Oct 2022 14:25:29 GMT

It is not important, or at least way less important than with a linear order by.

I cannot guarantee that the resulting files will be exactly the same, but z-ordering is not the same as a classic order by where we first order by col1 and then col2 etc. It will interleave the order columns and aim for locality on this 'combined' column.

Re: Question regarding ZORDER option of OPTIMIZE

leos1 — Thu, 13 Oct 2022 15:06:38 GMT

thanks for the quick reply