This command is used to register an index table with the primary table.

REGISTER INDEX TABLE indextable_name ON db_name.maintable_name;

**Table 1** REFRESH INDEX TABLE parameters
Parameter	Description
db_name	Database name. If this parameter is not specified, the current database is selected.
indextable_name	Index table name.
maintable_name	Primary table name.

Before running this command, run REFRESH TABLE to register the primary table and secondary index table with the Hive metastore.

create database productdb;

use productdb;

CREATE TABLE productSalesTable(a int,b string,c string) stored as carbondata;

create index productNameIndexTable on table productSalesTable(c) as 'carbondata';

insert into table productSalesTable select 1,'a','aaa';

create database productdb2;

Run the hdfs command to copy productSalesTable and productNameIndexTable in the productdb database to the productdb2 database.

refresh table productdb2.productSalesTable ;

refresh table productdb2.productNameIndexTable ;

explain select * from productdb2.productSalesTable where c = 'aaa'; / The query command does not use an index table.

REGISTER INDEX TABLE productNameIndexTable ON productdb2.productSalesTable;

explain select * from productdb2.productSalesTable where c = 'aaa'; // The query command uses an index table.

By running this command, the index table will be registered to the primary table.