QueryDB

Refer below Map Reduce Program that can be used to delete  column qualifier from HBase Table - -------- # Set HBase class path export HADOOP_CLASSPATH=`hbase classpath` #execute MR hadoop jar Test-0.0.1-SNAPSHOT.jar com.test.mymr.DeleteHBaseColumns --------- Refer - https://github.com/dinesh028/engineering/blob/master/src/com/test/mymr/DeleteHBaseColumns.java

Cause - This dummy column is added by Phoenix- if someone created Phoenix table on top of existing HBase table. Solutions-  Following solutions can be used to delete _0 column from each row -  Execute Unix command like below -  echo "scan 'ns:tbl1', {COLUMNS => 'cf:_0'}" |hbase shell | grep "column=cf:_0" | cut -d' ' -f 2 | awk '{$1=$1};1'|sed -e 's/^/delete '"'"'ns:tbl1'"'"', '"'"'/' -e 's/$/'"'"', '"'"'cf:_0'"'"'/'  | hbase shell Above command will scan rows which has these columns and prepare delete statements and execute them to remove _0 column. But, above will not give a good performance in case of bigger tables. ------------------------------------------------------------------------------------------------------------------------- Other Solution can b...