Re: text fields and performance for ETL

On Fri, 2021-11-05 at 09:51 +0000, Grega Jesih wrote:
> Suggested current text addendum:
>
> But, if you consider doing ETL from Postgres database to some outer target
> environment and you seek performance in such interfaces, follow the logic
> of limited size (varchar or char) data types in your database model.
> Because if you make a dataflow of known size types, interface code can take
> a big block of data while for text fields you need to check each record.

I am opposed to that.

It is not our business to discuss the limitations of a certain third-party software product.
If that were something wide-spread, perhaps. But I myself have never seen a problem
with "text", as long as the actual size of the data is moderate.
 
> Optional additional remark:
>
> Another good aspect of known data sizes is easier understanding of field
> content and implicit data (length) control.

Something like that makes more sense to me.

Perhaps, right before the tip you quoted, something like that:

If your use case requires a length limit on character data, or compliance
with the SQL standard is important, use "character varying".
Otherwise, you are usually better off with "text".

Yours,
Laurenz Albe