Daniel John Debrunner wrote:
Mike Matrigali wrote:
Mike Matrigali wrote:
Daniel John Debrunner wrote:
Mike Matrigali wrote:
I think I am missing/not understanding your direction.
are there still 4 new types?
No, collation becomes an attribute of the existing character types
just like length and nullability are.
What is CollatorSQLChar in your proposal then?
Same as in Mamta's current code.
CollatorSQLChar is a DataValueDescriptor, these are holders for values
of a type, they are not a type themselves. I think that's where the
confusion is coming in.
A type in Derby is composed of much more. The type definition of a
column is described by a DataTypeDescriptor, it is this class that would
hold extra information (an int) to describe the collation type. Also
some changes for classes involved in type creation at compile time will
be needed, CharTypeCompiler at least.
A writeup of the roles of the type classes is in the package.html for
the types package.
http://db.apache.org/derby/javadoc/engine/org/apache/derby/iapi/types/package-summary.html#package_description
So there would be four new classes that implement DataValueDescriptor,
for the Collator based collation of the four existing character types,
as Mamta has implicitly proposed. But there would not be four new
internal types and all the overhead it entails.
Thanks, this is what I was missing (I was using type when I meant
class). Overhead of collation will be avoided in the default by at
compile time getting the code to the right CLASS. Current db's will
be directed to SQLChar which will not need know anything about
collations, and collation created db's will get CollatorSQLChar instead
that will override as appropriate.
This seems reasonable to me. As I laid out in a previous message I
still think it appropriate in 10.3 to assume a single Collator for the
database and store it somewhere available at boot time before store
boots, and just let the datafactory somehow have it rather than make
store pass it in on every template object create. I believe if someone
has a future itch to allow for more than one collator per db there is
existing support to allow for the upgrade.
Dan.
