Re: Does Type Have = Operator? - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Does Type Have = Operator?
Date
Msg-id CA+TgmoZwVHh7ijmV=wLjRGizGH0kmY5ocVCnxBGrFqze0F6wQg@mail.gmail.com
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In response to Re: Does Type Have = Operator?  ("David G. Johnston" <david.g.johnston@gmail.com>)
Responses Re: Does Type Have = Operator?  ("David G. Johnston" <david.g.johnston@gmail.com>)
List pgsql-hackers
On Tue, May 10, 2016 at 9:16 PM, David G. Johnston
<david.g.johnston@gmail.com> wrote:
> Brute force: you'd have to query pg_amop and note the absence of a row with
> a btree (maybe hash too...) family strategy 3 (1 for hash) [equality] where
> the left and right types are the same and match the type in question.

The core system uses this kind of thing to find equality operators in
a number of cases.

We often assume that the operator which implements equality for the
type's default btree operator class is the canonical one for some
purpose.  Ditto for the default hash operator class.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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