Optimization to achieve at most one cdbRelMaxSegSize() call in function ATExecAlterColumnType.
Optimization to achieve at most one cdbRelMaxSegSize() call in function
ATExecAlterColumnType.

kaknikhil/gpdb,Chibin/gpdb,rvs/gpdb,rvs/gpdb,xinzweb/gpdb,lisakowen/gpdb,yuanzhao/gpdb,xuegang/gpdb,edespino/gpdb,50wu/gpdb,xinzweb/gpdb,chrishajas/gpdb,royc1/gpdb,cjcjameson/gpdb,rvs/gpdb,janebeckman/gpdb,Chibin/gpdb,xuegang/gpdb,royc1/gpdb,chrishajas/gpdb,edespino/gpdb,xuegang/gpdb,rvs/gpdb,kaknikhil/gpdb,CraigHarris/gpdb,yuanzhao/gpdb,xuegang/gpdb,0x0FFF/gpdb,chrishajas/gpdb,xuegang/gpdb,yuanzhao/gpdb,edespino/gpdb,lintzc/gpdb,lintzc/gpdb,greenplum-db/gpdb,lintzc/gpdb,ashwinstar/gpdb,adam8157/gpdb,ashwinstar/gpdb,janebeckman/gpdb,ashwinstar/gpdb,rvs/gpdb,jmcatamney/gpdb,Quikling/gpdb,edespino/gpdb,greenplum-db/gpdb,janebeckman/gpdb,edespino/gpdb,xinzweb/gpdb,lintzc/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,0x0FFF/gpdb,ashwinstar/gpdb,Quikling/gpdb,xuegang/gpdb,lintzc/gpdb,xinzweb/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,0x0FFF/gpdb,lisakowen/gpdb,Chibin/gpdb,CraigHarris/gpdb,kaknikhil/gpdb,xinzweb/gpdb,Quikling/gpdb,jmcatamney/gpdb,50wu/gpdb,Chibin/gpdb,rvs/gpdb,adam8157/gpdb,50wu/gpdb,adam8157/gpdb,chrishajas/gpdb,Quikling/gpdb,yuanzhao/gpdb,xuegang/gpdb,xinzweb/gpdb,Chibin/gpdb,rvs/gpdb,Chibin/gpdb,xinzweb/gpdb,50wu/gpdb,xuegang/gpdb,Quikling/gpdb,royc1/gpdb,ashwinstar/gpdb,royc1/gpdb,greenplum-db/gpdb,royc1/gpdb,greenplum-db/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,janebeckman/gpdb,adam8157/gpdb,chrishajas/gpdb,lisakowen/gpdb,jmcatamney/gpdb,janebeckman/gpdb,cjcjameson/gpdb,50wu/gpdb,CraigHarris/gpdb,lisakowen/gpdb,edespino/gpdb,edespino/gpdb,cjcjameson/gpdb,CraigHarris/gpdb,CraigHarris/gpdb,Chibin/gpdb,CraigHarris/gpdb,0x0FFF/gpdb,janebeckman/gpdb,edespino/gpdb,janebeckman/gpdb,yuanzhao/gpdb,rvs/gpdb,royc1/gpdb,janebeckman/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,0x0FFF/gpdb,ashwinstar/gpdb,royc1/gpdb,yuanzhao/gpdb,chrishajas/gpdb,edespino/gpdb,Chibin/gpdb,Chibin/gpdb,50wu/gpdb,CraigHarris/gpdb,Quikling/gpdb,greenplum-db/gpdb,kaknikhil/gpdb,lisakowen/gpdb,ashwinstar/gpdb,0x0FFF/gpdb,50wu/gpdb,jmcatamney/gpdb,CraigHarris/gpdb,edespino/gpdb,cjcjameson/gpdb,rvs/gpdb,0x0FFF/gpdb,adam8157/gpdb,lisakowen/gpdb,Quikling/gpdb,ashwinstar/gpdb,lisakowen/gpdb,lintzc/gpdb,cjcjameson/gpdb,janebeckman/gpdb,cjcjameson/gpdb,CraigHarris/gpdb,lintzc/gpdb,Quikling/gpdb,cjcjameson/gpdb,Quikling/gpdb,chrishajas/gpdb,Quikling/gpdb,kaknikhil/gpdb,cjcjameson/gpdb,royc1/gpdb,jmcatamney/gpdb,kaknikhil/gpdb,0x0FFF/gpdb,adam8157/gpdb,xinzweb/gpdb,lintzc/gpdb,Chibin/gpdb,50wu/gpdb,rvs/gpdb,greenplum-db/gpdb,janebeckman/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,adam8157/gpdb,lisakowen/gpdb,xuegang/gpdb,kaknikhil/gpdb,adam8157/gpdb,lintzc/gpdb,chrishajas/gpdb