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From "geoff hendrey (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-1748) Global case insensitive setting
Date Tue, 24 Jun 2008 01:43:45 GMT

    [ https://issues.apache.org/jira/browse/DERBY-1748?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12607439#action_12607439
] 

geoff hendrey commented on DERBY-1748:
--------------------------------------

Hi Rick,

Sorry I did not review 455, because it appears my proposal is identical to 455. Issue 455
correctly notes that the function being indexed must be even more constrained than scalar;
it must be deterministic. I had only considered the fact that it must be scalar (cannot be
an aggregate).

I would be fine with the proposal for generated columns, 481, assuming my read of its description
is correct. That is:
1) updates and inserts propagate seamlessly to the generated columns
2) dropping the "owner" column can seamlessly cascade to dropping the generated column
3) any indexes created on the generated column seamlessly disappear when the generated column
is dropped

Is my understanding correct?

> Global case insensitive setting
> -------------------------------
>
>                 Key: DERBY-1748
>                 URL: https://issues.apache.org/jira/browse/DERBY-1748
>             Project: Derby
>          Issue Type: New Feature
>          Components: SQL
>            Reporter: Terry
>
> By default MySQL is case insensitive in its string comparisons, as you can see from the
MySQL docs shown below. Similar functionality is available in Sybase iAnywhere and in SQLServer.
I'd like the same to be true for Derby.
> What, I wonder, are chances of that?
> I am aware that functions could be used to force comparisons in upper case but that subverts
the indexes and makes searches unacceptably long.
> If you were to ask people you might find that this is a feature whose abscence is causing
many to look elsewhere.
> thanks for all the great work,
> Terry
> The MySQL Docs say:
> -------- start quote
>  By default, MySQL searches are not case sensitive (although there are some character
sets that are never case insensitive, such as czech). This means that if you search with col_name
LIKE 'a%', you get all column values that start with A or a. If you want to make this search
case sensitive, make sure that one of the operands has a case sensitive or binary collation.
For example, if you are comparing a column and a string that both have the latin1 character
set, you can use the COLLATE operator to cause either operand to have the latin1_general_cs
or latin1_bin collation. For example:
> col_name COLLATE latin1_general_cs LIKE 'a%'
> col_name LIKE 'a%' COLLATE latin1_general_cs
> col_name COLLATE latin1_bin LIKE 'a%'
> col_name LIKE 'a%' COLLATE latin1_bin
> If you want a column always to be treated in case-sensitive fashion, declare it with
a case sensitive or binary collation. See Section 13.1.5, "CREATE TABLE Syntax". 
>     By default, the search is performed in case-insensitive fashion. In MySQL 4.1 and
up, you can make a full-text search by using a binary collation for the indexed columns. For
example, a column that has a character set of latin1 can be assigned a collation of latin1_bin
to make it case sensitive for full-text searches.
> --------------- end quote

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