#Postgres collate mac os
#Postgres collate Patch

It would be fine on glibc but abysmal on solaris, for example. It is possible to call setlocale() repeatedly, though the performance will be variable across platforms.

However, it is undesirable to have the COLLATE support depend on which platform you are running. OSes which don't include the BSDs, HPUX and Solaris.ДЇor this reason you can actually hack multi-locale sorting in some operating systems using a pg_strxfrm() function and creating a functional index on that.

#Postgres collate mac os

This includes Win32, Linux/glibc and Mac OS X. This is somewhat restrictive, so most major operating systems have provided variation that work with multiple locales. POSIX collation only works on the current locale. Strcoll(a,b) = strcmp( strxfrm(a), strxfrm(b) ) The former takes a string and converts it to another string that can be passed to strcmp() to do the actual comparison.

POSIX collation support basically consists of two functions: strxfrm() and strcoll(). It's also a major problem because virtually all databases have some strings that should be considered as plain ascii strings (such as path names, urls, or even codes like 'Y' and 'N') even if they have localizable strings as well. Note that this is intrinsically broken because you can choose the encoding per database but usually collation implementations only work on a particular encoding. PostgreSQL currently only supports one collation at a time, as fixed by the LC_COLLATE variable at the time the database cluster is initialised. Functions need to know what collation their arguments are, so a field is to be added to the fmgr structure.So fields need to be added to the executor to track this. At any point in a query only a single collation is current. The collation is a property of a column, not of a value.The only part missing is teaching the planner what indexes may be used for what COLLATE statement, and underlying support for multiple collations (see Todo:ICU). It also has all the necesary changes for b-tree to work with these collations.

#Postgres collate Patch

This patch covers all the catalog changes and syntax changes required for SQL complaint COLLATE support.

For review: Initial support for COLLATE.

Proof of concept COLLATE support with patch.

Charset/collate support and function parameters.

However, in the general case you could probably have a meaningful discussion about how geometric shapes could be ordered. This is also the only case the SQL standard worries about. In general it only applies to strings because that's the only case that has any kind of debate. A collation is a set of rules about how a set of objects should be ordered.