On 16 November 2015 at 17:47, Ashutosh Bapat < ashutosh.ba...@enterprisedb.com> wrote: > > > collations arising from a foreign table's var are considered to be safer > (FDW_COLLATE_SAFE) to push down to the foreign server , since they are > either local default collation or are assumed to be same on foreign and > local server as per user declaration. The onus of making that sure is on > the user who declares particular collation for a foreign table var. As said > upthread, different glibc implementations can cause collation ordering > mismatch, this patch will be susceptible to the same problem as > master/standby problem. > > Yeah. It's less bad than the related problems we already have:
* Upgrading glibc can cause your indexes to no longer match your local collations * Different glibc versions on master and replica(s) can have the same effect I don't see a problem with adding another way this same issue can be expressed, since there's no sane way to fix it _properly_ without either versioned collations in glibc or bringing collation onboard into Pg. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
