Unix Technical Forum

Re: Patch for collation using ICU

This is a discussion on Re: Patch for collation using ICU within the pgsql Hackers forums, part of the PostgreSQL category; --> Ok,.. tested on debian sarge with ICU 3.2 UNICODE Database, C locale. upper() and lower() returns an empty string ...


Go Back   Unix Technical Forum > Database Server Software > PostgreSQL > pgsql Hackers

FAQ Members List Calendar Search Today's Posts Mark Forums Read
  #1 (permalink)  
Old 04-11-2008, 04:13 AM
John Hansen
 
Posts: n/a
Default Re: Patch for collation using ICU

Ok,.. tested on debian sarge with ICU 3.2
UNICODE Database, C locale.

upper() and lower() returns an empty string for any input, including
7bit ascii, regardless of client_encoding, so something is obviously
broken.

Have you tested this patch on a UNICODE DB with locale C/POSIX ?

.... John

> -----Original Message-----
> From: John Hansen
> Sent: Friday, March 25, 2005 10:27 PM
> To: 'Palle Girgensohn'; 'pgsql-hackers@postgresql.org'
> Subject: RE: [HACKERS] Patch for collation using ICU
>
> > --On fredag, mars 25, 2005 16.34.41 +1100 John Hansen
> > <john@geeknet.com.au>
> > wrote:
> >
> > > Useful if it's going to support earlier releases of ICU....
> > >
> > > Not all os's come with ICU3.2, debian for example,

> > currently has 2.1
> > > in testing, and 2.6 in unstable.

> >
> > Oh, OK. FreeBSD has only the 3.2 as port. I can check the older
> > version, I doubt it would too much difference. Some

> autoconf sorcery
> > needed, perhaps.

>
> Naww, it's no biggie, we'll just need to include ICU with pg I think.
> I tried that, there are several functions from ICU that you
> use, that are not in ICU2.1
>
> Dono about 2.6.
>
> However, ICU3.2 compiles on debian with a small change to the
> debian/rules file.
> debian/tmp/etc is missing, so add mkdir debian/tmp/etc
>
> ... John
>
> >
> > /Palle
> >
> > >
> > > ... John
> > >
> > >> -----Original Message-----
> > >> From: pgsql-hackers-owner@postgresql.org
> > >> [mailtogsql-hackers-owner@postgresql.org] On Behalf Of Palle
> > >> Girgensohn
> > >> Sent: Friday, March 25, 2005 10:40 AM
> > >> To: pgsql-hackers@postgresql.org
> > >> Subject: [HACKERS] Patch for collation using ICU
> > >>
> > >> Hi!
> > >>
> > >> I've put together a patch for using IBM's ICU package for

> > collation.
> > >>
> > >> If your OS does not have full support for collation ur
> > >> uppercase/lowercase in multibyte locales, this might be

> useful. If
> > >> you are using a multibyte character encoding in your

> database and
> > >> want collation, i.e. order by, and also lower(), upper() and
> > >> initcap() to work properly, this patch will do just that.
> > >>
> > >> This patch is needed for FreeBSD, since this OS has no

> support for
> > >> collation of for example unicode locales (that is,

> wcscoll(3) does
> > >> not do what you expect if you set LC_ALL=sv_SE.UTF-8, for

> > example).
> > >> AFAIK the patch is *not* necessary for Linux, although IBM

> > claims ICU
> > >> collation to be about twice as fast as glibc for simple western
> > >> locales.
> > >>
> > >> It adds a configure switch, `--with-icu', which will set

> > up the code
> > >> to use ICU instead of wchar_t and wcscoll.
> > >>
> > >> This has been tested only on FreeBSD-4.11 &

> > FreeBSD-5-stable, where
> > >> it seems to run well. I've not had the time to do any

> comparative
> > >> performance tests yet, but it seems it is at least not

> slower than
> > >> using LATIN1 with
> > >> sv_SE.ISO8859-1 locale, perhaps even faster.
> > >>
> > >> I'd be delighted if some more experienced postgresql

> hackers would
> > >> review this stuff. The patch is pretty compact, so it's

> > fast reading
> > >> I'm planning to add this patch as an option (tagged
> > >> "experimental") to FreeBSD's postgresql port. Any ideas

> > about whether
> > >> this is a good idea or not?
> > >>
> > >> Any thoughts or ideas are welcome!
> > >>
> > >> Cheers,
> > >> Palle
> > >>
> > >> Patch at:
> > >> <http://people.freebsd.org/~girgen/po...u/pg-801-icu-2
> > > 005-03-14.diff>
> > >>
> > >> ICU at sourceforge: <http://icu.sf.net/>
> > >>
> > >>
> > >> ---------------------------(end of
> > >> broadcast)---------------------------
> > >> TIP 7: don't forget to increase your free space map settings
> > >>
> > >>

> >
> >
> >
> >
> >
> >


---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #2 (permalink)  
Old 04-11-2008, 04:13 AM
Palle Girgensohn
 
Posts: n/a
Default Re: Patch for collation using ICU


--On fredag, mars 25, 2005 23.39.33 +1100 John Hansen <john@geeknet.com.au>
wrote:

> Ok,.. tested on debian sarge with ICU 3.2
> UNICODE Database, C locale.
>
> upper() and lower() returns an empty string for any input, including
> 7bit ascii, regardless of client_encoding, so something is obviously
> broken.
>
> Have you tested this patch on a UNICODE DB with locale C/POSIX ?


No, honestly not. Mostly tested it with my needs, sv_SE.UTF-8 and UNICODE,
and also de_DE.UTF-8.

How will PostgreSQL react to this combo? A database cluster initdb:ed with
locale=C/POSIX, and then a database in UNICODE (really utf-8)
representation... hmm... I think I might have made a false assumption that
the locale string would contain the character encoding. I do something like
encoding = strchr(locale, '.') + 1... That code will be confused by a 'C'
locale, indeed. I'll check it out!

/Palle



>
> ... John
>
>> -----Original Message-----
>> From: John Hansen
>> Sent: Friday, March 25, 2005 10:27 PM
>> To: 'Palle Girgensohn'; 'pgsql-hackers@postgresql.org'
>> Subject: RE: [HACKERS] Patch for collation using ICU
>>
>> > --On fredag, mars 25, 2005 16.34.41 +1100 John Hansen
>> > <john@geeknet.com.au>
>> > wrote:
>> >
>> > > Useful if it's going to support earlier releases of ICU....
>> > >
>> > > Not all os's come with ICU3.2, debian for example,
>> > currently has 2.1
>> > > in testing, and 2.6 in unstable.
>> >
>> > Oh, OK. FreeBSD has only the 3.2 as port. I can check the older
>> > version, I doubt it would too much difference. Some

>> autoconf sorcery
>> > needed, perhaps.

>>
>> Naww, it's no biggie, we'll just need to include ICU with pg I think.
>> I tried that, there are several functions from ICU that you
>> use, that are not in ICU2.1
>>
>> Dono about 2.6.
>>
>> However, ICU3.2 compiles on debian with a small change to the
>> debian/rules file.
>> debian/tmp/etc is missing, so add mkdir debian/tmp/etc
>>
>> ... John
>>
>> >
>> > /Palle
>> >
>> > >
>> > > ... John
>> > >
>> > >> -----Original Message-----
>> > >> From: pgsql-hackers-owner@postgresql.org
>> > >> [mailtogsql-hackers-owner@postgresql.org] On Behalf Of Palle
>> > >> Girgensohn
>> > >> Sent: Friday, March 25, 2005 10:40 AM
>> > >> To: pgsql-hackers@postgresql.org
>> > >> Subject: [HACKERS] Patch for collation using ICU
>> > >>
>> > >> Hi!
>> > >>
>> > >> I've put together a patch for using IBM's ICU package for
>> > collation.
>> > >>
>> > >> If your OS does not have full support for collation ur
>> > >> uppercase/lowercase in multibyte locales, this might be

>> useful. If
>> > >> you are using a multibyte character encoding in your

>> database and
>> > >> want collation, i.e. order by, and also lower(), upper() and
>> > >> initcap() to work properly, this patch will do just that.
>> > >>
>> > >> This patch is needed for FreeBSD, since this OS has no

>> support for
>> > >> collation of for example unicode locales (that is,

>> wcscoll(3) does
>> > >> not do what you expect if you set LC_ALL=sv_SE.UTF-8, for
>> > example).
>> > >> AFAIK the patch is *not* necessary for Linux, although IBM
>> > claims ICU
>> > >> collation to be about twice as fast as glibc for simple western
>> > >> locales.
>> > >>
>> > >> It adds a configure switch, `--with-icu', which will set
>> > up the code
>> > >> to use ICU instead of wchar_t and wcscoll.
>> > >>
>> > >> This has been tested only on FreeBSD-4.11 &
>> > FreeBSD-5-stable, where
>> > >> it seems to run well. I've not had the time to do any

>> comparative
>> > >> performance tests yet, but it seems it is at least not

>> slower than
>> > >> using LATIN1 with
>> > >> sv_SE.ISO8859-1 locale, perhaps even faster.
>> > >>
>> > >> I'd be delighted if some more experienced postgresql

>> hackers would
>> > >> review this stuff. The patch is pretty compact, so it's
>> > fast reading
>> > >> I'm planning to add this patch as an option (tagged
>> > >> "experimental") to FreeBSD's postgresql port. Any ideas
>> > about whether
>> > >> this is a good idea or not?
>> > >>
>> > >> Any thoughts or ideas are welcome!
>> > >>
>> > >> Cheers,
>> > >> Palle
>> > >>
>> > >> Patch at:
>> > >> <http://people.freebsd.org/~girgen/po...u/pg-801-icu-2
>> > > 005-03-14.diff>
>> > >>
>> > >> ICU at sourceforge: <http://icu.sf.net/>
>> > >>
>> > >>
>> > >> ---------------------------(end of
>> > >> broadcast)---------------------------
>> > >> TIP 7: don't forget to increase your free space map settings
>> > >>
>> > >>
>> >
>> >
>> >
>> >
>> >
>> >






---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #3 (permalink)  
Old 04-11-2008, 04:13 AM
Tom Lane
 
Posts: n/a
Default Re: Patch for collation using ICU

Palle Girgensohn <girgen@pingpong.net> writes:
> hmm... I think I might have made a false assumption that
> the locale string would contain the character encoding.


You certainly cannot assume that. Would that it were so easy to find
out the character set for a locale :-(.

There's some code in initdb that you might emulate, though I can't say
that I trust it a whole lot.

regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?

http://www.postgresql.org/docs/faq

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #4 (permalink)  
Old 04-11-2008, 04:13 AM
Andrew Dunstan
 
Posts: n/a
Default Re: Patch for collation using ICU



Tom Lane wrote:

>Palle Girgensohn <girgen@pingpong.net> writes:
>
>
>>hmm... I think I might have made a false assumption that
>>the locale string would contain the character encoding.
>>
>>

>
>You certainly cannot assume that. Would that it were so easy to find
>out the character set for a locale :-(.
>
>There's some code in initdb that you might emulate, though I can't say
>that I trust it a whole lot.
>
>
>
>


Me either. On FC3 I saw this the other day, haven't had time to dig into
what's going on:

[andrew inst]$ echo $LANG
en_US.UTF-8
[andrew inst]$ bin/initdb floobl
The files belonging to this database system will be owned by user "andrew".
This user must also own the server process.

The database cluster will be initialized with locale en_US.UTF-8.
initdb: could not find suitable encoding for locale "en_US.UTF-8"
Rerun initdb with the -E option.
Try "initdb --help" for more information.



cheers

andrew

---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #5 (permalink)  
Old 04-11-2008, 04:13 AM
Palle Girgensohn
 
Posts: n/a
Default Re: Patch for collation using ICU


--On fredag, mars 25, 2005 09.53.38 -0500 Tom Lane <tgl@sss.pgh.pa.us>
wrote:

> Palle Girgensohn <girgen@pingpong.net> writes:
>> hmm... I think I might have made a false assumption that
>> the locale string would contain the character encoding.

>
> You certainly cannot assume that. Would that it were so easy to find
> out the character set for a locale :-(.
>
> There's some code in initdb that you might emulate, though I can't say
> that I trust it a whole lot.


Best thing would of course be to check the encoding of the database. I
realized I've made a bad assumption that the initdb locale has anything to
do with the character encoding of the database - it doesn't. There must be
some already existsing trusted way to get the character encoding of a
database?

/Palle


---------------------------(end of broadcast)---------------------------
TIP 4: Don't 'kill -9' the postmaster

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #6 (permalink)  
Old 04-11-2008, 04:15 AM
Peter Eisentraut
 
Posts: n/a
Default Re: Patch for collation using ICU

Andrew Dunstan wrote:
> The database cluster will be initialized with locale en_US.UTF-8.
> initdb: could not find suitable encoding for locale "en_US.UTF-8"


What does

$ LC_ALL=en_US.UTF-8 locale charmap

show?

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

---------------------------(end of broadcast)---------------------------
TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #7 (permalink)  
Old 04-11-2008, 04:16 AM
Andrew Dunstan
 
Posts: n/a
Default Re: Patch for collation using ICU



Peter Eisentraut wrote:

>Andrew Dunstan wrote:
>
>
>>The database cluster will be initialized with locale en_US.UTF-8.
>>initdb: could not find suitable encoding for locale "en_US.UTF-8"
>>
>>

>
>What does
>
>$ LC_ALL=en_US.UTF-8 locale charmap
>
>show?
>
>
>


[andrew pgsql]$ LC_ALL=en_US.UTF-8 locale charmap
UTF-8
[andrew pgsql]$

cheers

andrew

---------------------------(end of broadcast)---------------------------
TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #8 (permalink)  
Old 04-11-2008, 04:16 AM
Peter Eisentraut
 
Posts: n/a
Default Re: Patch for collation using ICU

Andrew Dunstan wrote:
> [andrew pgsql]$ LC_ALL=en_US.UTF-8 locale charmap
> UTF-8


That seems normal. Time to get out the debugger, I suppose.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?

http://www.postgresql.org/docs/faq

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On
Forum Jump


All times are GMT. The time now is 04:49 AM.


Powered by vBulletin® Version 3.6.5
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.2.0
www.UnixAdminTalk.com