Re: Upgrade Codec 99 to 101 / 102

Hi Uwe

Thanks for your feedback!

I am using now:

private final int maxDimensions =16384;

Codec codec =new Lucene101Codec() {
     @Override public KnnVectorsFormat getKnnVectorsFormatForField(String field) {var delegate =new Lucene102HnswBinaryQuantizedVectorsFormat();
         return new DelegatingKnnVectorsFormat(delegate,maxDimensions);
     }
};
return codec;

This seems to work fine, but I do not understand whether there is a difference anymore between float32 and int8 vector values,
or whetherLucene102HnswBinaryQuantizedVectorsFormat always "quantizes" the values?

Thanks

Michael


Am 10.09.25 um 10:19 schrieb Uwe Schindler:
>
> Hi,
>
> I think the best is to check the source code of default codec of the 
> upgrade version and start from there. I agree, there should possibly a 
> documentation available that gives the default componenets used in the 
> default codec of a given release.
>
> Uwe
>
> Am 09.09.2025 um 22:49 schrieb Michael Wechner:
>>
>> Hi
>>
>> With Lucene 9.12.0 I set my own custom max vector dimension using
>>
>> Codec codecInt8 = new Lucene99Codec() { @Override public 
>> KnnVectorsFormat getKnnVectorsFormatForField(String field) { var 
>> delegate = new Lucene99HnswScalarQuantizedVectorsFormat(); 
>> log.info("Vector Value Type: int8, Maximum Vector Dimension: " + 
>> maxDimensions); return new DelegatingKnnVectorsFormat(delegate, 
>> maxDimensions); } }; and
>> Codec codecFloat32 =new Lucene99Codec() {
>>      @Override public KnnVectorsFormat getKnnVectorsFormatForField(String field) {
>>          var delegate =new Lucene99HnswVectorsFormat();
>>          log.info("Vector Value Type: float32, Maximum Vector Dimension: " +maxDimensions);
>>          return new DelegatingKnnVectorsFormat(delegate,maxDimensions);
>>      }
>> };
>>
>> I am a little confused re which Codec / Vector Format classes I should use when upgrading to Lucene version 10.2.2
>>
>> Any hints would be much appreciated!
>>
>> Thanks
>>
>> Michael
>>
>>
> -- 
> Uwe Schindler
> Achterdiek 19, D-28357 Bremen
> https://www.thetaphi.de
> eMail:[email protected]