On 9/8/16 11:08 PM, Peter Geoghegan wrote: > In principle, and assuming I haven't gotten something wrong, it ought > to be possible to unambiguously identify a collation based on a > matching UCA version (i.e. DUCET table), plus the collation tailorings > matching exactly, even across ICU versions that happen to be based on > the same UCA version (they only seem to put out a new UCA version > about once a year ). It *might* be fine, practically speaking, to > assume that a collation with a matching iso-code and UCA version is > compatible forever and always across any ICU version. If not, it might > instead be feasible to write a custom fingerprinter for collation > tailorings that ran at initdb time.
The documentation  states that the collation version covers a broad range of things. So I don't think these additional mechanisms you describe are necessary. : http://userguide.icu-project.org/collation/architecture#TOC-Versioning -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers