Re: Subqueries or Joins? Problems with multiple table query

On 23 February 2010 13:23, Stefan Schwarzer
<stefan(dot)schwarzer(at)grid(dot)unep(dot)ch> wrote:
>> Select countries.name, basel.year, basel.value, cites.year, cites.value
>> From countries
>> Left Join basel on basel.id_country = countries.id_country and
>> basel.value=1
>> Left Join cites on cites.id_country = countries.id_country and
>> cites.value=1
>
> I would have thought so, but the query turns forever.

How many rows in each of your tables, and what indexes do you have?

You may also wish to review Andreas' suggestions as they propose a
more sensible table structure rather than having a table for each
convention.

You may also be interested in the tablefunc contrib module to help
present your data in the format you require rather than having a join
for each convention:
http://www.postgresql.org/docs/8.4/static/tablefunc.html

Thom