Re: [SQL] left join where not null vs. inner join

On May 22, 2009, at 1:51 PM, Emi Lu wrote: Two tables, each contains more than hundreds of thousands records. Is there any efficiency differences between (1) and (2)? (1) T1 inner join T2 using (c1, c2) (2) T1 left join T2 using (c1, c2) where c2 is not null Yes, stick with the first. I

[SQL] left join where not null vs. inner join

Two tables, each contains more than hundreds of thousands records. Is there any efficiency differences between (1) and (2)? (1) T1 inner join T2 using (c1, c2) (2) T1 left join T2 using (c1, c2) where c2 is not null Thanks, -- Lu Ying -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql