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Thread: [HACKERS] COMPRESS VALUES feature request

[HACKERS] COMPRESS VALUES feature request

From
Erez Segal
Date:
Hi,

Following a discussion in the IRC channel, I'd like to suggest a feature request to the ToDo WIKI page.

The use case is having a column with strings/floats, where some values are very common and can be compressed, while many other values are unique, making a lookup table not efficient.

It can be part of a column definition, set in CREATE TABLE/ALTER TABLE
e.g. field VARCHAR(255) COMPRESS (NULL, 'EREZ', 'SEGAL')


In the IRC channel - johto suggested an implementation:

<johto> if you want to get really fancy you could have two columns where only one of set; one would be the value (if reasonably unique) and the other the id (if not)
I'd like to add that an ENUM can be used instead of the id+lookup table in the 2nd column for non unique values.


Re: [HACKERS] COMPRESS VALUES feature request

From
Marko Tiikkaja
Date:
On Tue, May 9, 2017 at 8:18 PM, Erez Segal <erezsegal@gmail.com> wrote:
In the IRC channel - johto suggested an implementation:

<johto> if you want to get really fancy you could have two columns where only one of set; one would be the value (if reasonably unique) and the other the id (if not)

I only suggested how to do this in an application if one really wants the feature so badly.  I don't think this would fly as a native implementation.
 
I'd like to add that an ENUM can be used instead of the id+lookup table in the 2nd column for non unique values.

An ENUM in postgres *is* an id + lookup table..


.m