Re: [GENERAL] "Reverse" inheritance?

[vinny]

On 2017-04-04 09:12, Tim Uckun wrote:

I agree with the barking up the wrong tree, building a physical tree

in tables doesn't sound right
given that you will have to create a new branch in the tree when a new
version/variation of ubuntu comes out.

This doesn't bother me that much.


It should. You are using tables as data, which is pretty much always a 
smell of bad design.
I could be pedantic and ask how you would store unix version "14.5 
\%funky penguin%/ rev 1,5"
given that most of that name consists of characters that are not allowed 
in a table name.





Also think about how you are going to do basic queries like listing

all known unix variants; if that is hidden in the table namesthen
you'll have to issue DDL queries to do the work of SELECT queries,
which just sounds wrong to me.

Yes this might be a problem but one I could easily overcome.


Sure, but why would you though? You already have everything in place for 
creating records,

why bother creating a different system just for the unix versions?





I'd go for a tree, possibly using recursive CTE's to dig it.


I was thinking a window function but yea I am sure there is a way to
do it with a flat table.


I'm not sure you can do it with windowing actually,
given that you'd have to sort every record based on a match with the 
previous record.

But I've never tried it because CTE's make it so easy :-)



On Tue, Apr 4, 2017 at 6:43 PM, vinny  wrote:


I agree with the barking up the wrong tree, building a physical tree
in tables doesn't sound right
given that you will have to create a new branch in the tree when a
new version/variation of ubuntu comes out.

Also think about how you are going to do basic queries like listing
all known unix variants; if that is hidden in the table names
then you'll have to issue DDL queries to do the work of SELECT
queries, which just sounds wrong to me.

I'd go for a tree, possibly using recursive CTE's to dig it.

On 2017-04-04 05:19, Tim Uckun wrote:
I have thought of doing something like a single table inheritance
and it
could be done but I thought this might be a little more elegant.

On Tue, Apr 4, 2017 at 2:15 PM, David G. Johnston <
david.g.johns...@gmail.com> wrote:

On Mon, Apr 3, 2017 at 7:07 PM, Tim Uckun 
wrote:

I am trying to make postgres tables work like an object hierarchy.
As an
example I have done this.

​I suspect you are barking up the wrong tree ;)

You are probably better off incorporating something like the "ltree"
type
to encode the taxonomy.

https://www.postgresql.org/docs/current/static/ltree.html [1]

I haven't had a chance to leverage it myself but the concept it
embodies
is solid.

David J.
​




Links:
--
[1] https://www.postgresql.org/docs/current/static/ltree.html



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Re: [GENERAL] "Reverse" inheritance?

[Tim Uckun]

>I agree with the barking up the wrong tree, building a physical tree in
tables doesn't sound right
given that you will have to create a new branch in the tree when a new
version/variation of ubuntu comes out.

This doesn't bother me that much. If can say create table ubuntu_17_04
inherits ubuntu and have it return all the parents data as I described it
would be awesome

>Also think about how you are going to do basic queries like listing all
known unix variants; if that is hidden in the table names
then you'll have to issue DDL queries to do the work of SELECT queries,
which just sounds wrong to me.

Yes this might be a problem but one I could easily overcome.

>I'd go for a tree, possibly using recursive CTE's to dig it.

I was thinking a window function but yea I am sure there is a way to do it
with a flat table.

On Tue, Apr 4, 2017 at 6:43 PM, vinny  wrote:

> I agree with the barking up the wrong tree, building a physical tree in
> tables doesn't sound right
> given that you will have to create a new branch in the tree when a new
> version/variation of ubuntu comes out.
>
> Also think about how you are going to do basic queries like listing all
> known unix variants; if that is hidden in the table names
> then you'll have to issue DDL queries to do the work of SELECT queries,
> which just sounds wrong to me.
>
> I'd go for a tree, possibly using recursive CTE's to dig it.
>
>
> On 2017-04-04 05:19, Tim Uckun wrote:
>
>> I have thought of doing something like a single table inheritance and it
>> could be done but I thought this might be a little more elegant.
>>
>> On Tue, Apr 4, 2017 at 2:15 PM, David G. Johnston <
>> david.g.johns...@gmail.com> wrote:
>>
>> On Mon, Apr 3, 2017 at 7:07 PM, Tim Uckun  wrote:
>>>
>>> I am trying to make postgres tables work like an object hierarchy. As an
 example I have done this.


>>> ​I suspect you are barking up the wrong tree ;)
>>>
>>> You are probably better off incorporating something like the "ltree" type
>>> to encode the taxonomy.
>>>
>>> https://www.postgresql.org/docs/current/static/ltree.html
>>>
>>> I haven't had a chance to leverage it myself but the concept it embodies
>>> is solid.
>>>
>>> David J.
>>> ​
>>>
>>>

Re: [GENERAL] "Reverse" inheritance?

[vinny]

I agree with the barking up the wrong tree, building a physical tree in 
tables doesn't sound right
given that you will have to create a new branch in the tree when a new 
version/variation of ubuntu comes out.


Also think about how you are going to do basic queries like listing all 
known unix variants; if that is hidden in the table names
then you'll have to issue DDL queries to do the work of SELECT queries, 
which just sounds wrong to me.


I'd go for a tree, possibly using recursive CTE's to dig it.

On 2017-04-04 05:19, Tim Uckun wrote:
I have thought of doing something like a single table inheritance and 
it

could be done but I thought this might be a little more elegant.

On Tue, Apr 4, 2017 at 2:15 PM, David G. Johnston <
david.g.johns...@gmail.com> wrote:


On Mon, Apr 3, 2017 at 7:07 PM, Tim Uckun  wrote:

I am trying to make postgres tables work like an object hierarchy. As 
an

example I have done this.



​I suspect you are barking up the wrong tree ;)

You are probably better off incorporating something like the "ltree" 
type

to encode the taxonomy.

https://www.postgresql.org/docs/current/static/ltree.html

I haven't had a chance to leverage it myself but the concept it 
embodies

is solid.

David J.
​




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To make changes to your subscription:
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Re: [GENERAL] "Reverse" inheritance?

[Tim Uckun]

I have thought of doing something like a single table inheritance and it
could be done but I thought this might be a little more elegant.

On Tue, Apr 4, 2017 at 2:15 PM, David G. Johnston <
david.g.johns...@gmail.com> wrote:

> On Mon, Apr 3, 2017 at 7:07 PM, Tim Uckun  wrote:
>
>> I am trying to make postgres tables work like an object hierarchy. As an
>> example I have done this.
>>
>
> ​I suspect you are barking up the wrong tree ;)
>
> You are probably better off incorporating something like the "ltree" type
> to encode the taxonomy.
>
> https://www.postgresql.org/docs/current/static/ltree.html
>
> I haven't had a chance to leverage it myself but the concept it embodies
> is solid.
>
> David J.
> ​
>

Re: [GENERAL] "Reverse" inheritance?

[David G. Johnston]

On Mon, Apr 3, 2017 at 7:07 PM, Tim Uckun  wrote:

> I am trying to make postgres tables work like an object hierarchy. As an
> example I have done this.
>

​I suspect you are barking up the wrong tree ;)

You are probably better off incorporating something like the "ltree" type
to encode the taxonomy.

https://www.postgresql.org/docs/current/static/ltree.html

I haven't had a chance to leverage it myself but the concept it embodies is
solid.

David J.
​