Re: GIN Index for low cardinality

> 17 окт. 2018 г., в 13:46, Ravi Krishna <srkrishna1(at)aol(dot)com> написал(а):
>
> In https://www.cybertec-postgresql.com/en/ideas-for-scaling-postgresql-to-multi-terabyte-and-beyond/ <https://www.cybertec-postgresql.com/en/ideas-for-scaling-postgresql-to-multi-terabyte-and-beyond/>
>
> it is mentioned:
>
> "GIN, the most know non-default index type perhaps, has been actually around for ages (full-text search) and in short is perfect for indexing columns where there are lot of repeating values – think all kinds of statuses or good old Mr/Mrs/Miss. GIN only stores every unique column value only once as for the default B-tree you’ll have e.g. 1 millon leaf nodes with the integer “1” in it."
>
>
> Does it mean that GIN is a very good choice for low cardinality columns.

Not necessary. There is other index which also don’t keep column value in an every leaf. Hash, for instance.