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From "Mamta A. Satoor (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-3320) Database creation and boot should fail if collation=TERRITORY_BASED and the selected locale is not supported
Date Wed, 19 Mar 2008 17:54:24 GMT

    [ https://issues.apache.org/jira/browse/DERBY-3320?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12580477#action_12580477
] 

Mamta A. Satoor commented on DERBY-3320:
----------------------------------------

I am starting to think of the implementation for the following approach 
At the db create time, we will give the error for Collator not available (if that is the case)
when the database is getting created rather than wait until a user creates a table with char
column. For the database boot time, throw the error whenever the Collator is accessed first(ie
not right towards the end of the boot time in BasicDatabase). This first access can happen
because recovery was required during boot time or later when user has triggered access to
Collator through SQL.

With the above approach in mind, I am thinking that I will keep the changes in DVF.setLocale(the
changes shown in the patch attached to this jira entry) where I check if we are in here for
database create time and check for Collator object and if found, put it in collatorForCharacterTypes
class variable. If not for database create time, don't even create the Collator object in
DVF.setLocale ie do not load collatorForCharacterTypes.

DVF has a method called getCharacterCollator which now will have to see if it is dealing with
territory based db, If yes, then check if collatorForCharacterTypes is not null. If not null,
then return collatorForCharacterTypes otherwise it mean that Collator object is getting accessed
for the first time and hence check if the JVM supports it. If not, then throw exception. If
it is supported, then put the Collator object in collatorForCharacterTypes and return collatorForCharacterTypes
from getCharacterCollator. So, as we can see, now we will have an additional check for territory
based db in getCharacterCollator to see if collatorForCharacterTypes is null or not and if
null, then verify that Collator is supported by the JVM. Pseudo code follows

DVF.getCharacterCollator  (as it is in trunk)
    	if (collationType == StringDataValue.COLLATION_TYPE_UCS_BASIC)
    		return (RuleBasedCollator)null;
    	else
    		return collatorForCharacterTypes;    	

The new code for DVF.getCharacterCollator will be
    	if (collationType == StringDataValue.COLLATION_TYPE_UCS_BASIC)
    		return (RuleBasedCollator)null;
    	else if (collatorForCharacterTypes == null) {
                                           Collator object supported by JVM for databaseLocale?
                                           If not, throw exception
                                           If yes, then collatorForCharacterTypes = Collator
object
  		    return collatorForCharacterTypes;    	
    	} else
    		return collatorForCharacterTypes;    	


> Database creation and boot should fail if collation=TERRITORY_BASED and the selected
locale is not supported
> ------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-3320
>                 URL: https://issues.apache.org/jira/browse/DERBY-3320
>             Project: Derby
>          Issue Type: Bug
>    Affects Versions: 10.4.0.0
>         Environment: Java ME:
> Product: phoneME Advanced (phoneme_advanced_mr2-b34)
> Profile: Foundation Profile Specification 1.1
> Linux 2.4.21-40.ELsmp #1 SMP Thu Feb 2 22:14:12 EST 2006 i686 athlon i386 GNU/Linux
>            Reporter: Vemund Østgaard
>            Assignee: Mamta A. Satoor
>         Attachments: DERBY_3320_not_ready_for_commit_diff_v1.txt, DERBY_3320_not_ready_for_commit_stat_v1.txt,
DERBY_3320_Repro.java
>
>
> A problem I've discovered when testing with the phoneME advanced platform is that the
collationtests expect other locales than Locale.US to be available on the platform that is
used for the test, and for phoneME advanced (when compiled as foundation profile) only Locale.US
is available. From the jdk1.6 javadoc of Collator.getAvailableLocales() I see that only Locale.US
is strictly required:
> public static Locale[] getAvailableLocales()
>     Returns an array of all locales for which the getInstance methods of this class can
return localized instances. The returned array represents the union of locales supported by
the Java runtime and by installed CollatorProvider implementations. It must contain at least
a Locale instance equal to Locale.US.
>     Returns:
>         An array of locales for which localized Collator instances are available.
> This led me to thinking about how Derby should behave if created/booted with collation=TERRITORY_BASED
and territory=<some unsupported locale>. I'm not sure what the consequences could be
if the database is first created on a platform that supports whatever locale is set and later
booted with one that doesn't, or created on a platform missing support and later booted with
one that has. In any case I think it may confuse a user needlessly to see the database boot
successfully with his collation setting and later behave in a way he does not expect.
> Opinions voiced on the derby-dev list are that both database creation and boot should
fail if collation=TERRITORY_BASED and the selected locale is not supported.
> If a change like this is implemented, the collationtests should be changed to verify
correct behavior also if they are executed in an environment were some of the tested locales
are not supported.

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