I have obtained a great performance improvement now just adding an index in the 2 columns
dtfrom and idcatalogue, removing the 2 single indexes on the column dtfrom and idcatalogue. I could not believe, now the query SELECT MAX(DTFROM) AS MAXDT, IDCATALOGUE FROM CRONOCATALOGUES GROUP BY IDCATALOGUE takes only 2 seconds in sqlite and 5 seconds in access. May be the field idcatalogue has not to be found in the table anymore because it is in the index (this is my explanation, but I'm not sure). Could not imagine such an improvement! Sorry for my ignorance. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users