You're seeing just the function
field_schema_keyword, go back to ExAliyunOts.Search module for more information.
:index, specifies whether to set as index, by default it is true;
:enable_sort_and_agg, specifies whether to support sort and statistics, by default it is true;
:store, specifies whether to store the origin value in search index for a better read performance, by default it is true;
:is_array, specifies whether the stored data is a JSON encoded list as a string, e.g.