Hi
We use drill to query hbase.
Recently I check one of our query's plan:
0: jdbc:drill:drillbit=rfdc2> explain plan for SELECT '2016-07-27 00:00' as
key, sum(convert_from(action.`v`.`c`,'INT_BE')) AS pv,COUNT(DISTINCT
BYTE_SUBSTR(action.row_key,-8,8)) AS uv,
SUM(convert_from(action.`v`.`s`,'INT_BE')) AS v from hbase.`action_combine`
as action where action.row_key >'020160727pay.search' and action.row_key
< '020160727pay.searci' ;
the result is :
+------+------+
| text | json |
+------+------+
| 00-00 Screen
00-01 Project(key=[$0], pv=[$1], uv=[$2], v=[$3])
00-02 Project(key=['2016-07-27 00:00'], pv=[$0], uv=[$2], v=[$1])
00-03 NestedLoopJoin(condition=[true], joinType=[inner])
00-05 StreamAgg(group=[{}], pv=[SUM($0)], v=[SUM($1)])
00-07 StreamAgg(group=[{}], pv=[SUM($0)], v=[SUM($2)])
00-08 Project($f0=[CONVERT_FROMINT_BE(ITEM($1, 'c'))],
$f1=[BYTE_SUBSTR($0, -8, 8)], $f2=[CONVERT_FROMINT_BE(ITEM($1, 's'))])
00-09 Scan(groupscan=[HBaseGroupScan
[HBaseScanSpec=HBaseScanSpec [tableName=action_combine,
startRow=020160727pay.search\x00, stopRow=020160727pay.searci,
filter=null], columns=[`*`]]])
00-04 StreamAgg(group=[{}], uv=[$SUM0($0)])
00-06 UnionExchange
01-01 StreamAgg(group=[{}], uv=[COUNT($0)])
01-02 HashAgg(group=[{0}])
01-03 Project($f1=[$0])
01-04 HashToRandomExchange(dist0=[[$0]])
02-01 UnorderedMuxExchange
03-01 Project($f1=[$0],
E_X_P_R_H_A_S_H_F_I_E_L_D=[hash32AsDouble($0)])
03-02 HashAgg(group=[{0}])
03-03 Project($f1=[BYTE_SUBSTR($0, -8, 8)])
03-04 Scan(groupscan=[HBaseGroupScan
[HBaseScanSpec=HBaseScanSpec [tableName=action_combine,
startRow=020160727pay.search\x00, stopRow=020160727pay.searci,
filter=null], columns=[`*`]]])
My question is as there have two scan in the plan , does this mean's the
query will execute twice?
