4 ms·

Correct. Using ICU collations avoids this problem. Also, with libc collations you have to rebuild indexes after a glibc upgrade: https://postgresql.verite.pro

• jakobegger 8y ago
  Even if you use ICU, you need to make sure you link with the same version of ICU! Edit: Why the downvote? New versions of Unicode come out every year, and ICU collations are explicitely versioned. If you use ICU 51.1 and ICU 52.1 you are going to have the same kind of issues
  • anarazel 8y ago
    ICU collations in PG are versioned, and ICU has support for accessing the different collation versions. So you might be stuck on an older collation version without explicit action, but it'll not yield wrong results.
    • jakobegger 8y ago
      Really? PostgreSQL can use an index created with an older version of ICU? I didn't know that. Edit: The docs say indices need to be rebuilt when ICU version changes: https://www.postgresql.org/docs/11/sql-altercollation.html https://www.postgresql.org/docs/11/sql-altercollation.html ICU offers a way to detect the collation version has changed, but I thought there was no way to access older collation versions.