On 2020-02-17 20:08, Daniel Verite wrote:
Concerning execution speed, there's an excessive CPU usage when normalizing into NFC or NFKC. Looking at pre-existing code, it looks like recompose_code() in unicode_norm.c looping over the UnicodeDecompMain array might be very costly.
Yes, this is a known issue and I think room for future optimization work.
Another point is that the ICU-based implementation appears to be significantly faster in all cases, which makes me wonder why ICU builds should not just use ICU instead of the PG-core implementation.
That would require linking libpq to ICU (for SASLprep), and in general would either make ICU required or require maintaining multiple implementations. I don't think we're there yet.
-- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
