alter_async

Daria Barysheva

Contents

Definition
Usage
Examples

Definition

Works in the same way as alter command, but does not wait for all Regions to receive the schema changes. So, unlike the alter command, the output does not contain the message "Updating all regions with the new schema…".

Usage

Adding or modifying a column family:

alter_async '[<namespace_name>:]<table_name>',
            '<column_family>' | {NAME => '<column_family>'[, <cf_attribute_name> => <cf_attribute_value>,...]}[,...]

Deleting a column family:

Method 1:

alter_async '[<namespace_name>:]<table_name>',
            NAME => '<column_family>',
            METHOD => 'delete'

Method 2:

alter_async '[<namespace_name>:]<table_name>',
            'delete' => '<column_family>'

Setting table-scope parameters:

alter_async '[<namespace_name>:]<table_name>',
            <table_attribute_name> => <table_attribute_value>[,...]

Resetting table-scope parameters:

alter_async '[<namespace_name>:]<table_name>',
            METHOD => 'table_att_unset',
            NAME => '<table_attribute_name>'

Setting configuration options:

alter_async '[<namespace_name>:]<table_name>',
            CONFIGURATION => {'<conf_attribute_name>' => <conf_attribute_value>[,...]}

Resetting configuration options:

alter_async '[<namespace_name>:]<table_name>',
            METHOD => 'table_conf_unset',
            NAME => '<conf_attribute_name>'

TIP

There could be more than one alteration in one command.

Arguments
Parameter	Description
namespace_name	A namespace name
table_name	A table name
column_family	A column family name
cf_attribute_name	A column family attribute name
cf_attribute_value	A value of the specified column family attribute
table_attribute_name	A table-scope attribute name
table_attribute_value	A value of the specified table-scope attribute
conf_attribute_name	A configuration attribute name
conf_attribute_value	A value of the specified configuration attribute

Examples

hbase(main):006:0> alter_async 't1', 'cf3'
Took 1.2380 seconds
hbase(main):007:0> describe 't1'
Table t1 is ENABLED
t1
COLUMN FAMILIES DESCRIPTION
{NAME => 'cf1', VERSIONS => '10', EVICT_BLOCKS_ON_CLOSE => 'false', NEW_VERSION_BEHAVIOR => 'false', KEEP_DELETED_CELLS => 'FALSE', CACHE_DATA_ON_WRITE => 'f
alse', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', MIN_VERSIONS => '0', REPLICATION_SCOPE => '0', BLOOMFILTER => 'ROW', CACHE_INDEX_ON_WRITE => 'false',
 IN_MEMORY => 'false', CACHE_BLOOMS_ON_WRITE => 'false', PREFETCH_BLOCKS_ON_OPEN => 'false', COMPRESSION => 'NONE', BLOCKCACHE => 'true', BLOCKSIZE => '65536
'}
{NAME => 'cf2', VERSIONS => '1', EVICT_BLOCKS_ON_CLOSE => 'false', NEW_VERSION_BEHAVIOR => 'false', KEEP_DELETED_CELLS => 'FALSE', CACHE_DATA_ON_WRITE => 'fa
lse', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', MIN_VERSIONS => '0', REPLICATION_SCOPE => '0', BLOOMFILTER => 'ROW', CACHE_INDEX_ON_WRITE => 'false',
IN_MEMORY => 'false', CACHE_BLOOMS_ON_WRITE => 'false', PREFETCH_BLOCKS_ON_OPEN => 'false', COMPRESSION => 'NONE', BLOCKCACHE => 'true', BLOCKSIZE => '65536'
}
{NAME => 'cf3', VERSIONS => '1', EVICT_BLOCKS_ON_CLOSE => 'false', NEW_VERSION_BEHAVIOR => 'false', KEEP_DELETED_CELLS => 'FALSE', CACHE_DATA_ON_WRITE => 'fa
lse', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', MIN_VERSIONS => '0', REPLICATION_SCOPE => '0', BLOOMFILTER => 'ROW', CACHE_INDEX_ON_WRITE => 'false',
IN_MEMORY => 'false', CACHE_BLOOMS_ON_WRITE => 'false', PREFETCH_BLOCKS_ON_OPEN => 'false', COMPRESSION => 'NONE', BLOCKCACHE => 'true', BLOCKSIZE => '65536'
}
3 row(s)
Took 0.0181 seconds

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