Query plans not identical for `id in(1,2,3)` and `(id=1 or id=2 or id=3)` - Mailing list pgsql-general

Hi List.

I have a list of bigint keys and I need to retrieve rows by these keys. Normally, I would split this list into pages of
size900 and perform several `SELECT ... WHERE key in($1,$2,...)`. However, the proprietary ORM we use can only produce
thisSQL: `SELECT ... WHERE (key=$1 or key=$2 or ...)`. Surprisingly, PostgreSQL planner treats these two SQLs
differently:

- ```select * FROM "audittrail$referencelogline" where id in ( 1 , 2 , 3 )```

Index Scan
https://i.stack.imgur.com/dr8oz.png

- ```select * FROM "audittrail$referencelogline" where id = 1 or id = 2 or id = 3```

A lot of "Bitmap Index Scan" for each value 
https://i.stack.imgur.com/dnErs.png

Is it possible to configure PostgreSQL 12.16 to treat the second query as the first?