增加了对细分的支持
增加了对细分的支持
合并了i20分支
添加了对segment和join pop的支持
Merge remote-tracking branch 'origin/i20' into i16
Merge remote-tracking branch 'origin/i20' into i16
添加了对segment和join pop的支持
Merge remote-tracking branch 'origin/i20' into i16

Conflicts:
	sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/opt/BasicOptimizer.java
Merge remote-tracking branch 'origin/i20' into i16
Merge remote-tracking branch 'origin/i20' into i16

Conflicts:
	sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/opt/BasicOptimizer.java
Merge remote-tracking branch 'origin/i20' into i16
implement physical operator segment
Merge remote-tracking branch 'origin/i20' into i20
Merge remote-tracking branch 'origin/i20' into i20
Merge remote-tracking branch 'origin/i20' into i20
不带用户群的功能
test join , group by , aggregate together