is jc_compare asymmetrical in exact search?

Hi,





Would you please check the following sql? The first one returns 0, but second one returns 1. I thought exact search was symmetry operation.








select jc_compare(


'CC(=O)NC(CS)C(O)=O'


,


'CC(=O)N[C@@H](CS)C(O)=O'


, 't:e queryType:l') from dual;





select jc_compare(


'CC(=O)N[C@@H](CS)C(O)=O'


,


'CC(=O)NC(CS)C(O)=O'


, 't:e queryType:l') from dual;








Thanks





Bin

No, exact search is not symmetrical. Probably you want to do a Perfect search instead. In the examples you gave, the difference is because Exact and Perfect searching sets the exactStereoMatching flag differently. For explanation, see the description of the search types in the Query Guides:





http://www.chemaxon.com/jchem/doc/user/Query.html#otherSearchTypes





All the best,





Szabolcs

The follow-up question is why these two smiles are not exact matches (in the first query)? Thanks.

In the URL you provided, exact match does not require stereo matches, therefore the two structures seem should be considered a match in the first SQL. We did not want perfect match here.

What is the difference between steroSearching=n and exactlyStereoMatching=n? Please clarify. Thanks.

yzhou wrote:

The follow-up question is why these two smiles are not exact matches (in the first query)? Thanks.

In that case the query has stereo specification, but the target does not.

yzhou wrote:

In the URL you provided, exact match does not require stereo matches, therefore the two structures seem should be considered a match in the first SQL. We did not want perfect match here.

You are right, the documentation is not explicit regarding this. We will complete it. All of our search types consider stereochemistry by default.





You may find these examples useful: http://www.chemaxon.com/jchem/doc/user/QueryMatchExamples.html





(We will also make these pictures more noticeable in the documentation.)

yzhou wrote:

What is the difference between steroSearching=n and exactlyStereoMatching=n? Please clarify. Thanks.

stereoSearch:n instructs the search to ignore stereo information completely. (The default is stereoSearch:y, i.e. to consider stereo.)





exactStereoMatching:y means that all stereo information must be the same - i.e. non-stereo query matches only non-stereo target. The default exactStereoMatching:n makes a non-stereo query match to non-stereo target as well as all stereoisomers. A query with specific stereo information in all settings will only match the target with the same stereo specification.





Regards,


Szabolcs