Hello.
I have implemented the patch for Derby-134, which you mentioned.
The solution for Derby-134 in that patch was just only enabling use of expression like as "UPPER(text_val)" in order clause.
As in next URL mentioned, index with expression is not supported yet, and I did'nt make it support in that patch.
Only Simple-column-Name is supported.
http://incubator.apache.org/derby/manuals/reference/sqlj27.html#HDRSII-SQLJ-20937
//I feel there exists request for index with expression...
Then, if you want benefit of index,
you would need to prepare column which have value for sorting , and sort by the column for sorting in sql, in application program layer.
Best regards.
/*
Tomohito Nakayama
[EMAIL PROTECTED]
[EMAIL PROTECTED] Naka
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----- Original Message ----- From: "Joerg von Frantzius" <[EMAIL PROTECTED]>
To: <[email protected]>
Cc: <[email protected]>
Sent: Friday, April 22, 2005 5:12 PM
Subject: Derby-134, indexes and sorting locale-sensitive / case insensitive
Hi,
there had been a long discussion of Derby-134 ("Sorted string columns are sorted in a case sensitive way"), which in the end looked to me as being solved, i.e. someone has supplied a "good-looking" patch. Now is there any chance of a binary build coming up in the near future, where this patch would be included?
Talking about "ORDER BY", after reading the manuals about optimization and in particular http://incubator.apache.org/derby/manuals/tuning/perf45.html#Cost-Based+ORDER+BY+Sort+Avoidance
I'm still not sure about a few things. My problem is that I have a GUI with a table widget that displays >1500 rows, and I want to make use of Derby's index structures to have fast column sorting. Maybe that simply won't help here, because I need the ordering to be both locale-sensitive and case-insensitive.
With an ascending index on a VARCHAR column:
1. does that index default to case-insensitive ordering of the column?
2. does it maintain the ordering in a locale-sensitive way, e.g. by using java.text.Collator? (e.g. using the default locale active at index creation time)
3. will "ORDER BY ... DESCENDING" make use of the index by simply reversing its order, or will it result in full re-sorting with performance-penalty?
Thanks for any information, J�rg.
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