Re: pgsql: Adjust string comparison in jsonpath - Mailing list pgsql-committers

From Andrew Dunstan
Subject Re: pgsql: Adjust string comparison in jsonpath
Date
Msg-id 0ed83a33-d900-466a-880a-70ef456c721f@2ndQuadrant.com
Whole thread Raw
In response to pgsql: Adjust string comparison in jsonpath  (Alexander Korotkov <akorotkov@postgresql.org>)
Responses Re: pgsql: Adjust string comparison in jsonpath  (Thomas Munro <thomas.munro@gmail.com>)
List pgsql-committers
On 8/11/19 4:10 PM, Alexander Korotkov wrote:
> Adjust string comparison in jsonpath
>
> We have implemented jsonpath string comparison using default database locale.
> However, standard requires us to compare Unicode codepoints.  This commit
> implements that, but for performance reasons we still use per-byte comparison
> for "==" operator.  Thus, for consistency other comparison operators do per-byte
> comparison if Unicode codepoints appear to be equal.
>
> In some edge cases, when same Unicode codepoints have different binary
> representations in database encoding, we diverge standard to achieve better
> performance of "==" operator.  In future to implement strict standard
> conformance, we can do normalization of input JSON strings.
>


This appears to have upset prion when testing on en_US.iso885915.


cheers


andrew





-- 
Andrew Dunstan                https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services




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