Re: Questions about btree_gin vs btree_gist for low cardinality columns

From: "Peter J(dot) Holzer" <hjp-pgsql(at)hjp(dot)at>
To: pgsql-general(at)lists(dot)postgresql(dot)org
Subject: Re: Questions about btree_gin vs btree_gist for low cardinality columns
Date: 2019-05-31 08:11:36
Message-ID: 20190531081136.e3cmqyrji4edyxve@hjp.at
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On 2019-05-30 21:00:57 +0200, Peter J. Holzer wrote:
> Firstly, the GIN index doesn't generally index single characters. It
> uses some rule to split the field into tokens. For example, for a text
> field, it might split the field into words (possibly with some
> normalization like case-folding and stemming) for an int array it might
> use the values in the array, etc.

That was misleading: For a full text index you don't actually index the
column. You index ts_vector(columne). It is ts_vector which does the
tokenization, not the access method itself.

hp

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