how can we restrict the builds in bitbucket pipelines after each commit

[chintalapudi durgabhavani]

Hello All,

i am exploring on bitbucket cloud.i am using free trial version of bitbucket cloud

i have  cloned the sample repo from github for testing purpose.

my question here is: i dont want to trigger my pipeline for small change in the code.can we restrict the builds after each commit(since we have limited build minutes for free trail version).

or 

do we have any polling option to set particular time frame to trigger the build?