LocaleName (Rephrase)

[Ivan Smahin]

Hello Joakim,

Tuesday, December 12, 2006, 8:37:25 PM, you wrote:

> Ok,

> I have read the kernel document and it doesn't really answer my questions,
> actually it adds one :-) or I am uncertain about one thing. It is talking
> about 2 different kinds of encoding available, Storage Encoding and I/O
> encoding. It then doesn't meantion the latter anymore except telling it's
> what get into and out of fields. So althought stays unclear on this point I
> assume locale is the I/O encoding?

I would say:
When   you  set  some  I/O  Encoding  you  say:  "I promise to give to
valentina's  database  data  encoded in particular codepage and I want
to  get the data in that way back." It is per-session settings. I mean
you should set it each time you operate with database.
This  setting  does  not  touch  the  storage. It decodes your data to
storage encoding just before store it and encode storage-data each time
you retrieve it.
So this settings does not affect other sessions.

Storage  encoding  is responsible for how the database is storing the
data.  This setting is storable - so you don't need to set it each time.
It decodes any data to storage encoding just before store it.


> Then let me rephrase my previous questions and put it in as example of my
> database. In my database I store data about almost every City/Town available
> on the earth (except for very small places). The bigger part is numeric data
> but there is some VarChar fields typically for Town names and countries or
> other "labels", then there is 1 DateTime field. The database it set to
> Storage Encoding UTF-16.

> First, Country and Town names exist in various versions regarding spelling
> as they can spell differently in different languages. What I am concerned
> about here is that when the database is used on a computer these names will
> show as they should be in original language. All I/O controls in my app is
> full Unicode aware. Will the locale set in Valentina affect how this is
> displayed? I ask because in Vstudio this isn't the case always, but maybe
> Vstudio controls isn't Unicode?

It  should be so. If you operates with UTF16 - there is no need to set
any I/O Encoding.

> When populate data into database I have changed my computers setting to
> resamble that country, I have then read the data in by code from unicode
> files with correct spelling. So is this "preserved" inside Valentina dispite
> change of locale? Or locale has nothing to do with this how characters are
> displayed when UTF-16?

Yes.  It  would  be nothing to do if data comes as UTF16 and stored in
this way also.

> Second thing is my DateTime Field, will locale change how it behave or just
> how it "look"? Like in VB as an example, dates can be formated differently
> but inside VB always use the same format no matter which locale set. What I
> do here is typically compare one DateTime value from code with what is
> stored in db to find a range of datetime this falls into.

Currently  date  fields  is not affected by locale. There is different
properties set such as dateFormat, separator and so on.

> As I do now I only set locale to VarChar field and leave rest as original
> which is en_US (or if it en_UK), but setting locale to 1 field with 250 000
> records takes 4sec! But maybe Valentina have to traverse all records, then
> it's logical. However what I think is maybe I don't have to set locale at
> all? Well I am a bit confused about this :-) I don't know exactly how and
> what it affect in my db, like if it metetrs if I have UTF-16 whole database.

If you use the UTF-16 only you should do nothing in this area.



-- 
Best regards,
 Ivan                            mailto:ivan_smahin ÎÁ valentina-db.com