[GENERAL] RE: [GENERAL] how to import "where exists（subquery）" EXISTS CONDITION performance?

shili wrote: > I had saw this sentence: SQL statements that use the EXISTS condition in > PostgreSQL are very inefficient > since the sub-query is RE-RUN for EVERY row in the outer query's table. There > are more efficient ways > to write most queries, that do not use the EXISTS condition. >

[GENERAL] Re: [GENERAL] how to import "where exists（subquery）" EXISTS CONDITION performance?

On 2 December 2015 at 20:51, shili wrote: > I had saw this sentence: SQL statements that use the EXISTS condition in > PostgreSQL are very inefficient since the sub-query is RE-RUN for EVERY row > in the outer query's table. There are more efficient ways to write most >