Yang, Tong 6182f91ba8 MRS component operation guide_normal 2.0.38.SP20 version

Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com>
Co-authored-by: Yang, Tong <yangtong2@huawei.com>
Co-committed-by: Yang, Tong <yangtong2@huawei.com>

2022-12-09 14:55:21 +00:00

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REGISTER INDEX TABLE

Function

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

Syntax

REGISTER INDEX TABLE indextable_name ON db_name.maintable_name;

Parameter Description

**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.

Precautions

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

Examples

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.

System Response

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

Parent topic: DDL

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