Use few analyzers in GIN index in Postgres - sql

Question

I want to create GIN index for Postges full text search and I would like to ask is it possible if I store analyzer name for each row in table in separate column called lang, use it to create GIN index with different analyzer for each row taken from this field lang?
This is what I use now. Analyzer – ‘english’ and it is common for each row in indexed table.
CREATE INDEX CONCURRENTLY IF NOT EXISTS
decription_fts_gin_idx ON api_product
USING GIN(to_tsvector('english', description))
I want to do something like this:
CREATE INDEX CONCURRENTLY IF NOT EXISTS
decription_fts_gin_idx ON api_product
USING GIN(to_tsvector(api_product.lang, description))
( it doesnt work)
in order to retrieve analyzer configuration from field lang and use its name to populate index.
Is it possible to do it somehow or it is only possible to use one analyzer for the whole index?
DDL, just in case..
-- auto-generated definition
create table api_product
(
id serial not null
constraint api_product_pkey
primary key,
name varchar(100) not null,
standard varchar(40) not null,
weight integer not null
constraint api_product_weight_check
check (weight >= 0),
dimensions varchar(30) not null,
description text not null,
textsearchable_index_col tsvector,
department varchar(30) not null,
lang varchar(25) not null
);
alter table api_product
owner to postgres;
create index textsearch_idx
on api_product (textsearchable_index_col);
Query to run for seach:
SELECT *,
ts_rank_cd(to_tsvector('english', description),
to_tsquery('english', %(keyword)s), 32) as rnk
FROM api_product
WHERE to_tsvector('english', description) ## to_tsquery('english', %(keyword)s)
ORDER BY rnk DESC, id
where 'english' would be changed to 'lang' field analyzer name (english, french, etc)

Answer 1

If you know ahead of time the language you are querying against, you could create a series of partial indexes:
CREATE INDEX CONCURRENTLY ON api_product
USING GIN(to_tsvector('english', description)) where lang='english';
Then in your query you would add the language you are searching in:
SELECT *,
ts_rank_cd(to_tsvector('english', description),
to_tsquery('english', %(keyword)s), 32) as rnk
FROM api_product
WHERE to_tsvector('english', description) ## to_tsquery('english', %(keyword)s)
and lang='english'
ORDER BY rnk DESC, id

Answer 2

What you asked about is definitely possible, but you have the wrong type for the lang column:
create table api_product(description text, lang regconfig);
create index on api_product using gin (to_tsvector(lang, description));
insert into api_product VALUES ('the description', 'english');