19.10.2018 14:03, Adriano dos Santos Fernandes wrote:
ICU generates sort key for a single string. For multi segment (columns) index/sort, Firebird call ICU (or any collation) for each column and join the generated fully (with all levels/strengths) sort keys.
AFAIK, sorting key is just an array of bytes and sorting comparison routine treat it as an array of bytes. Key generation routine transform any data into an array of bytes and after that operation source data type is irrelevant. What levels do you talk about?
To generate interleaved keys and joins them in another manner, Firebird INTL interface should be changed, so Firebird could ask a collation for the sort key's levels/strengths separated.
Compound sort key is just a concatenation of single sort keys. At this point INTL module already out of business IIRC. What interface changes do you have on mind?
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