Hello guys:

I noticed that the column 'qty_available' in the list view of the module product is NOT sortable, and some other columns such as 'cost' 、'forecasted quantity' either.  

I looked into the relevant snippet in list_renderer.js  ,there is a function 'isSortable()' to check with one of properties named 'sortable':

isSortable(column) {
    const { hasLabel, name } = column;
    const { sortable } = this.fields[name];
    const { options } = this.props.list.activeFields[name];
    return (sortable || options.allow_order) && hasLabel;

And then I checked the field's properties in the console log and found the value of 'sortable' is 'false' :

I knew that computed fields which not stored in database can not be sorted,  but I'm wondering where is the source code determining a field's property 'sortable' ? 

Thanks in advance!