Re: Recursive merging of overlapping arrays in a column

From: Rob Sargent <robjsargent(at)gmail(dot)com>
To: pgsql-sql(at)postgresql(dot)org
Subject: Re: Recursive merging of overlapping arrays in a column
Date: 2015-09-20 14:00:00
Message-ID: 55FEBBE0.8090902@gmail.com
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On 09/20/2015 05:12 AM, dave wrote:
> Hey mailing list,
>
> i have the following Table:
>
>
>
> I want to merge the arrays which have overlapping elements, so that I get
> the result which doesn't contain overlapping arrays anymore:
>
>
> I am not an expert in SQL and it took me a long time to come up with this
> solution:
>
>
> Which gives me the result:
>
>
> Result number 3 is contained in number one and shouldn't be in the output
> anymore, because I only want non overlapping arrays in the result.
>
> Another problem I encountered is that the performance of this query seems to
> be very bad. I tried running it on a larger table (~400000 arrays) and it is
> still running after ~10h.
>
> I would appreciate any input on this problems, so it would be nice if anyone
> could give me a hint how to get only the merged arrays without overlaps in
> the resultset and maybe how to build a more elegant and efficient query.
>
>
> Thanks in advance,
>
> Dave
>
>
>
> --
> View this message in context: http://postgresql.nabble.com/Recursive-merging-of-overlapping-arrays-in-a-column-tp5866560.html
> Sent from the PostgreSQL - sql mailing list archive at Nabble.com.
>
>
I don't see your table def, sql nor result output. Suggest you re-post
with all those as plain text

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