reducebykey和groupbykey的區(qū)別 會(huì)不會(huì)對(duì)窗口函數(shù)和updatestatebykey函數(shù)?
會(huì)不會(huì)對(duì)窗口函數(shù)和updatestatebykey函數(shù)?在主示例代碼中,testdata RDD的類型被確定為RDD[(string,int)],然后RDD.rddtordp函數(shù)這個(gè)隱式類型轉(zhuǎn)換被轉(zhuǎn)換
會(huì)不會(huì)對(duì)窗口函數(shù)和updatestatebykey函數(shù)?
在主示例代碼中,testdata RDD的類型被確定為RDD[(string,int)],然后RDD.rddtordp函數(shù)這個(gè)隱式類型轉(zhuǎn)換被轉(zhuǎn)換成pairddfunctions[string,int],從而得到兩個(gè)方法reducebykey和combinebykey。