Could we print some warnings / performance suggestions in case of long iterations over existing results?
On Wed, Jan 28, 2015 at 2:11 PM, Valentin Kulichenko < [email protected]> wrote: > Currently, when continuous query is executed, it first iterates over > existing results before processing continuous updates. This iteration can > take a lot of time and not always needed. > > Imagine simple scenario: > > - Load initial data from DB to cache; > - Register continuous query for further updates that will happen while > application is running; > - Run the application. > > In most cases notifications on initial data are not needed, but you get > them regardless of whether you registered query before or after data > loading. > > I think we should add a flag on continuous query that allows to enable or > disable this behavior. Also I think that it should be disabled by default > because I really can't imaging a use case when you need to iterate through > the whole cache. Also it's not obvious what is happening in this case - if > user was not attentive enough reading the documentation and there is a lot > of data, he may think that query simply hanged during registration process. > > Thoughts? > -- Alexey Kuznetsov GridGain Systems www.gridgain.com
