Read HBase Tables using scan shell command and examples

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  • Post last modified:February 27, 2018
  • Post category:BigData
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The set of HBase basic operations are referred to as CRUD operations. i.e. create, read, update, delete operations. HBase scan command is used to get data out of HBase tables. In this article, we will check how to read HBase tables using scan shell command and various examples.

Read HBase Tables using scan shell command

HBase scan command

The HBase scan command is yet another HBase shell command that you can use to read the table. Scan command is similar to HBase get shell command but supports more options. The HBase scan command scans entire table and displays the table contents. You can execute HBase scan command with various other options or attributes such as TIMERANGE, FILTER, TIMESTAMP, LIMIT, MAXLENGTH, COLUMNS, CACHE, STARTROW and STOPROW.

We will use the table ‘personal’ that we have created as part of Insert data using HBase shell put command.

HBase Scan Command Syntax

Below is the HBase scan command syntax:

scan 'personal', {attributes => ‘value’}

HBase Scan Command Example

Example to read HBase table using scan command:

hbase(main):009:0> scan 'personal'
ROW COLUMN+CELL
 1 column=personal_data:age, timestamp=1505285659934, value=25
 1 column=personal_data:city, timestamp=1505285653043, value=Bengaluru
 1 column=personal_data:name, timestamp=1505285635428, value=Ram
 2 column=personal_data:age, timestamp=1505286495492, value=24
 2 column=personal_data:city, timestamp=1505286495492, value=Bengaluru
 2 column=personal_data:name, timestamp=1505286495492, value=sham

2 row(s) in 0.0460 seconds

HBase Scan command with various attributes or options:

hbase(main):008:0> scan 'personal' , {COLUMNS => 'personal_data:name', LIMIT => 10, STARTROW => '3'}
ROW COLUMN+CELL
 3 column=personal_data:name, timestamp=1505286495492, value=Guru
 4 column=personal_data:name, timestamp=1505286495492, value=John
 5 column=personal_data:name, timestamp=1505286495492, value=Rock

3 row(s) in 0.0150 seconds

HBase scan commands with Filters

Below are some examples to demonstrate how to use filter in hbase shell.

Below example explain use of HBase KeyOnlyFilter:

This filter does not take any arguments. It returns only the key component of each k

hbase(main):018:0> scan 'emp',{ FILTER => "KeyOnlyFilter()"}

ROW COLUMN+CELL
 1 column=personal_data:city, timestamp=1501587154609, value=
 1 column=personal_data:name, timestamp=1501587131490, value=
 10 column=personal_data:city, timestamp=1501590338062, value=
 11 column=personal_data:city, timestamp=1501590380498, value=
 12 column=personal_data:city, timestamp=1501591062068, value=
 13 column=personal_data:city, timestamp=1501592423889, value=
 14 column=personal_data:city, timestamp=1501592816324, value=
 15 column=personal_data:city, timestamp=1501596615499, value=
 16 column=personal_data:city, timestamp=1505197739790, value=
 16 column=personal_data:name, timestamp=1505197712574, value=
 2 column=personal_data:city, timestamp=1501588125116, value=
 3 column=personal_data:city, timestamp=1501588130621, value=
 4 column=personal_data:city, timestamp=1501588135719, value=
 5 column=personal_data:city, timestamp=1501588339919, value=
 6 column=personal_data:city, timestamp=1501588345310, value=
 7 column=personal_data:city, timestamp=1501589123534, value=
 8 column=personal_data:city, timestamp=1501589222829, value=
 9 column=personal_data:city, timestamp=1501590307575, value=

16 row(s) in 0.1070 seconds

For list of filters available in HBase, check out show_filter command section in “commonly used HBase Table management commands”

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