From: | Ian Barwick <ian(at)2ndquadrant(dot)com> |
---|---|
To: | David G Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: "RETURNING PRIMARY KEY" syntax extension |
Date: | 2014-06-09 06:17:12 |
Message-ID: | 53955168.9060300@2ndquadrant.com |
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Lists: | pgsql-hackers |
On 09/06/14 14:47, David G Johnston wrote:
> Ian Barwick wrote
>> Hi,
>>
>> The JDBC API provides the getGeneratedKeys() method as a way of retrieving
>> primary key values without the need to explicitly specify the primary key
>> column(s). This is a widely-used feature, however the implementation has
>> significant
>> performance drawbacks.
>>
>> Currently this feature is implemented in the JDBC driver by appending
>> "RETURNING *" to the supplied statement. However this means all columns of
>> affected rows will be returned to the client, which causes significant
>> performance problems, particularly on wide tables. To mitigate this, it
>> would
>> be desirable to enable the JDBC driver to request only the primary key
>> value(s).
>
> Seems like a good idea.
>
>
>> ERROR: Relation does not have any primary key(s)
>
> "Relation does not have a primary key."
> or
> "Relation has no primary key." (preferred)
>
> By definition it cannot have more than one so it must have none.
Ah yes, amazing what a fresh pair of eyes does :). The plural is
the vestige of an earlier iteration which said something about
the relation not having any primary key column(s).
Will fix, thanks.
Regards
Ian Barwick
--
Ian Barwick http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
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