added a plpgsql function for string multiplication
added a plpgsql function for string multiplication

prashasthip/peloton,AngLi-Leon/peloton,wangziqi2016/peloton,wangziqi2016/peloton,phisiart/peloton-p3,AllisonWang/peloton,eric-haibin-lin/peloton-1,vittvolt/peloton,cmu-db/peloton,PauloAmora/peloton,ShuxinLin/peloton,malin1993ml/peloton,yingjunwu/peloton,ShuxinLin/peloton,AngLi-Leon/peloton,eric-haibin-lin/peloton-1,haojin2/peloton,prashasthip/peloton,AllisonWang/peloton,apavlo/peloton,cmu-db/peloton,vittvolt/15721-peloton,jessesleeping/iso_peloton,ShuxinLin/peloton,apavlo/peloton,vittvolt/peloton,malin1993ml/peloton,prashasthip/peloton,vittvolt/peloton,AllisonWang/peloton,jessesleeping/iso_peloton,phisiart/peloton-p3,haojin2/peloton,AngLi-Leon/peloton,vittvolt/15721-peloton,haojin2/peloton,PauloAmora/peloton,phisiart/peloton-p3,PauloAmora/peloton,cmu-db/peloton,haojin2/peloton,PauloAmora/peloton,jessesleeping/iso_peloton,AngLi-Leon/peloton,vittvolt/15721-peloton,apavlo/peloton,ShuxinLin/peloton,ShuxinLin/peloton,yingjunwu/peloton,cmu-db/peloton,apavlo/peloton,vittvolt/peloton,vittvolt/15721-peloton,jessesleeping/iso_peloton,vittvolt/15721-peloton,vittvolt/15721-peloton,yingjunwu/peloton,PauloAmora/peloton,AllisonWang/peloton,prashasthip/peloton,malin1993ml/peloton,malin1993ml/peloton,eric-haibin-lin/peloton-1,yingjunwu/peloton,apavlo/peloton,vittvolt/peloton,wangziqi2016/peloton,malin1993ml/peloton,eric-haibin-lin/peloton-1,phisiart/peloton-p3,cmu-db/peloton,wangziqi2016/peloton,wangziqi2016/peloton,AllisonWang/peloton,malin1993ml/peloton,AngLi-Leon/peloton,AllisonWang/peloton,jessesleeping/iso_peloton,eric-haibin-lin/peloton-1,phisiart/peloton-p3,haojin2/peloton,phisiart/peloton-p3,seojungmin/peloton,yingjunwu/peloton,wangziqi2016/peloton,AngLi-Leon/peloton,seojungmin/peloton,jessesleeping/iso_peloton,jessesleeping/iso_peloton,seojungmin/peloton,vittvolt/peloton,prashasthip/peloton,seojungmin/peloton,eric-haibin-lin/peloton-1,PauloAmora/peloton,prashasthip/peloton,cmu-db/peloton,haojin2/peloton,seojungmin/peloton,apavlo/peloton,ShuxinLin/peloton,yingjunwu/peloton,seojungmin/peloton