Re: Two questions about "pg_constraint"

On 8/24/22 13:11, Bryn Llewellyn wrote:
> *Question 1: why does "pg_constraint" have a "connamespace" column?*
> 

> What do you think?
> 
> *Question 2: what happened to the column "consrc"?*
> 
> The PG 11 account of "pg_constraint"
> https://www.postgresql.org/docs/11/catalog-pg-constraint.html 
> <https://www.postgresql.org/docs/11/catalog-pg-constraint.html>
> 
> describes "consrc" (text) thus:
> 
> « If a check constraint, a human-readable representation of the expression »
> 
> Ad hoc queries in my PG 11.9 env show results like « (v = lower(v)) » in 
> this column for my tables. This is useful information. But the PG 14 
> version of "pg_constraint" has no such column (and nor does the doc 
> mention it). Is this information now exposed somewhere else?
> 

It was in 11 but not later, so lets look at release notes from 12 --> 14

Here in 12:

"

Remove obsolete pg_constraint.consrc column (Peter Eisentraut)

This column has been deprecated for a long time, because it did not 
update in response to other catalog changes (such as column renamings). 
The recommended way to get a text version of a check constraint's 
expression from pg_constraint is pg_get_expr(conbin, conrelid). 
pg_get_constraintdef() is also a useful alternative.
"

-- 
Adrian Klaver
adrian.klaver@aklaver.com