How ResultSet works

[wrushasen dakhane]

Hi All,

I know that the implementation of ResultSet and all the JDBC API is provided by the vendor specific drivers For ex: classes12.jar

Consider the senario where the select statement returns 1 million rows how it will handled by the ResultSet...

Wrushasen D

[Merrill Higginson]

As you mentioned, the implementation of ResultSet is vendor specific, but I don't believe there's a simgle implementation that will retrieve all million rows and try to store them in memory. The ResultSet will fetch a number of rows at a time, and as the client code iterates through the rows, it will keep fetching more rows as needed.

That's why it's so important to remember that a ResultSet object is only valid while the connection to the database is still live. The ResultSet itself may not contain all the data. It's merely a proxy that communicates with the database to retrieve data as needed.