Postgres 9 : - How to interpret the EXPLAIN query results

[Khangelani Gama <kgama@xxxxxxxxxxxx>]

Hi

 

Please help, how can I interpret the following results of my EXPLAIN query ?, I can see that the query will through 18586018 rows, but whatâ??s the meaning of cost and width?

 

GroupAggregate  (cost=762381141.96..768375132.77 rows=18586018 width=32)

 

 

 

 

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