On Friday, September 8, 2017, John Turner <fenwayri...@gmail.com> wrote:
> > > On Fri, Sep 8, 2017 at 6:57 AM Tom Lane <t...@sss.pgh.pa.us > <javascript:_e(%7B%7D,'cvml','t...@sss.pgh.pa.us');>> wrote: > >> Ron Johnson <ron.l.john...@cox.net >> <javascript:_e(%7B%7D,'cvml','ron.l.john...@cox.net');>> writes: >> > Based on LENGTH(offending_column), none of the values are more than 144 >> > bytes in this 44.2M row table. Even though VARCHAR is, by definition, >> > variable length, are there any internal design issues which would make >> > things more efficient if it were dropped to, for example, VARCHAR(256)? >> >> No. >> >> So the declarative column length has no bearing on memory grants during > plan generation/execution? > Nope. Memory usage is proportional to the size of the string, not the maximum length for varchar. Maximum length is a constraint. merlin
