Re: Preserve versions of initdb-created collations in pg_upgrade

On 2019-10-29 03:33, Thomas Munro wrote:
> Seems to work as described with -E UTF-8, but it fails with clusters
> using -E SQL_ASCII.  That causes the pg_upgrade check to fail on
> machines where that is the default encoding chosen by initdb (where
> unpatched master succeeds):
> 
> pg_restore: creating COLLATION "pg_catalog.af-NA-x-icu"
> pg_restore: while PROCESSING TOC:
> pg_restore: from TOC entry 1700; 3456 12683 COLLATION af-NA-x-icu tmunro
> pg_restore: error: could not execute query: ERROR:  collation
> "pg_catalog.af-NA-x-icu" for encoding "SQL_ASCII" does not exist
> Command was: ALTER COLLATION pg_catalog."af-NA-x-icu" OWNER TO tmunro;

This could be addressed by using is_encoding_supported_by_icu() in 
pg_dump to filter out collations with unsupported encodings.

However, the more I look at this whole problem, I'm wondering whether it 
wouldn't be preferable to avoid this whole mess by just not creating any 
collations in initdb.  What do you think?

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services