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From Apache Wiki <wikidi...@apache.org>
Subject [Db-derby Wiki] Update of "BuiltInLanguageBasedOrderingDERBY-1478" by MamtaSatoor
Date Tue, 20 Mar 2007 16:37:08 GMT
Dear Wiki user,

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The following page has been changed by MamtaSatoor:

  4)Store column level metadata for collate in Language Layer as well. This will happen in
DataTypeDescriptor(DTD) with the addition of int collateType field. It will be set to 0(UCS_BASIC)/1(TERRITORY_BASED)/-1(UNKNOWN).
There will be get and set methods on DTD for this new field.
+ 5)The TypeDescriptor for character columns always has 0 for scale because scale does not
apply to character datatypes. Starting Derby 10.3, this scale field in TypeDescriptor will
be overloaded to indicate the collate type of the character. So, if user has requested for
TERRITORY_BASED collation, then the collate type in TypeDescriptor for user columns(character)
will be 1(TERRITORY_BASED). The collate type will be 0(UCS_BASIC) for SYS schema character
columns and for databases with collation set to UCS_BASIC.
+ 6)At the time of upgrade of pre-10.3 databases, we should make sure that collation of these
databases is marked as UCS_BASIC. This is because we do not plan on supporting collation change
for existing databases.
+ 7)When a character column is added using CREATE TABLE/ALTER TABLE, make sure that the correct
collate type is populated in the TypeDescriptor in the SYS.SYSCOLUMNS table.
  == Implemented items ==
  1)A shell for subclass of SQLChar has been implemented and it is called CollatorSQLChar.
It resides in derby.iapi.types package.

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