Vinnie wrote: > PRAGMA statements, I see what you mean now. This is exactly what I needed, > thanks a lot. > > To clarify what I am doing, my SQL statements are in UTF-8 and they are all > prepared, with parameter bindings. So table names, column names, etc.. are > all UTF-8. > > However, I have table fields which will be UTF-16. For example, filenames > that have to support international character sets. Or metadata fields that > use different character sets (UNICODE). For these I am using > sqlite3_bind_text16() and passing an appropriate wchar_t buffer. > > On the other hand there is some legacy data that I want to store using UTF-8. > For these fields I will use sqlite3_bind_text(). It is possible that in a > single INSERT statement there are both UTF-16 and UTF-8 (wchar_t and char) > fields present. > > At no point am I ever constructing SQL statements using a printf() style > conversion on field data to create the statement. > > Am I vulnerable to a performance penalty because of conversions in this > scenario? > > Thanks > >From what I can see, i'd say no, binds are converted once (iirc) and referenced from there on forwards, quoted strings are generally where the performance hit comes in, as they're converted every step of the vm (so for a select statement, every sqlite3_step over the result set). > > >> Igor Tandetnik wrote: >> >>> You can mix and match encodings in your application. >>> >> The database >> >>> encoding determines how strings are actually stored in >>> >> the file (and >> >>> it's database-wide, not per table). SQLite API >>> >> converts back and forth >> >>> as necessary. >>> >>> >> Very inneficiently, but yes, it does. I suggest to the OP >> to use >> parameterised queries if you need to use string values, >> otherwise, >> you'll see significant overhead from conversions back >> and forth between >> utf8 and utf16 inside the sqlite code. >> >>> Igor Tandetnik >>> > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > >
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