> Hello, please, is there any way to make SQLite use an index on two > columns when I want to select all rows which have some combination of > the two columns?
> SELECT * FROM PointFeature WHERE > DsetId=203 AND SectId IN (4,400); I can't answer the question you asked, but I will point out one thing. Many SQL engines attempt to optimize index use in queries. For instance, in MS SQL Server, your query might *not* use the second column in the index if using the index would take perform more poorly than not using it. Using an index is not always faster than doing a table scan. If there are only a few rows where DsetId is equal to 203, the table scan of that subset could very well be faster than using an index to look up the values. In our MS SQL Server environment, we usually don't even bother to create indexes on more than one field if there are going to be less than a few hundred rows in a subset of a query like that. It takes the server longer to do the index lookup than it would the table scan.
