I'm creating an edge table, how to prevent duplicating edges

Asked Dec 08 '17 at 08:25

Active Dec 08 '17 at 08:43

Viewed 45 times

The query is like so:

       CREATE TABLE Edge_Table AS
       SELECT a.*gid,nextval('ty') AS edge_gid, 
       ST_SetSRID(ST_MakeLine(a.geom, getcentroids(a.gid)),4326) AS geom_line 
       FROM Points_table a;

where my getcentroids Function returns 8 nearest points to each point creating an edge with each one of them, the problem arises with duplicates as same edge is created from 1->2 and 2->1, how do I optimise this query itself as large data has to be processed, could index or UNIQUE constraint help?

edited Dec 08 '17 at 08:43

Panup Pong

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asked Dec 08 '17 at 08:25

shivam thakur

a `UNIQUE` constraint on the column and a `DISTINCT` in your selection query will do the job. – Akli REGUIG Dec 08 '17 at 10:55

I'm creating an edge table, how to prevent duplicating edges

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