ALTER MATERIALIZED VIEW

Changes materialized view table properties. The statement returns no results.

Restriction:

Changing columns is not supported.
Change log, CDC, is not available for materialized views.

Synopsis

ALTER MATERIALIZED VIEW [<keyspace_name>.]<view_name>
  WITH <table_options> [ AND <table_options> ... ] ;

Syntax legend

Legend
Syntax conventions	Description
UPPERCASE	Literal keyword.
Lowercase	Not literal.
`< >`	Variable value. Replace with a user-defined value.
`[]`	Optional. Square brackets (`[]`) surround optional command arguments. Do not type the square brackets.
`( )`	Group. Parentheses ( `( )` ) identify a group to choose from. Do not type the parentheses.
`\|`	Or. A vertical bar (`\|`) separates alternative elements. Type any one of the elements. Do not type the vertical bar.
`...`	Repeatable. An ellipsis ( `...` ) indicates that you can repeat the syntax element as often as required.
`'<Literal string>'`	Single quotation (`'`) marks must surround literal strings in CQL statements. Use single quotation marks to preserve upper case.
`{ <key> : <value> }`	Map collection. Braces (`{ }`) enclose map collections or key value pairs. A colon separates the key and the value.
`<datatype2`	Set, list, map, or tuple. Angle brackets ( `< >` ) enclose data types in a set, list, map, or tuple. Separate the data types with a comma.
`<cql_statement>;`	End CQL statement. A semicolon (`;`) terminates all CQL statements.
`[--]`	Separate the command line options from the command arguments with two hyphens ( `--` ). This syntax is useful when arguments might be mistaken for command line options.
`' <<schema\> ... </schema\>> '`	Search CQL only: Single quotation marks (`'`) surround an entire XML schema declaration.
`@<xml_entity>='<xml_entity_type>'`	Search CQL only: Identify the entity and literal value to overwrite the XML element in the schema and solrConfig files.

keyspace_name

Selects a keyspace.

view_name

Selects the materialized view.

table_options

Table options are defined when the materialized view is created. Modify the table_options in the WITH clause using the following syntax:

Single value using the <option_name> = '<value>'. Enclose string values in single quotes, and no quotes for numbers, boolean, etc.
Specify options with multiple subproperties in simple JSON format, <option_name> = { <option_map> }.
Set multiple table options using AND.

Examples

Modifying table properties

Add a comment and set the bloom filter properties:

ALTER MATERIALIZED VIEW cycling.cyclist_by_age 
  WITH comment = 'A most excellent and useful view'
  AND bloom_filter_fp_chance = 0.02;

For an overview of properties that apply to materialized views, see table_options.

Modifying compression and compaction

Use a property map to specify new properties for compression or compaction.

ALTER MATERIALIZED VIEW cycling.cyclist_by_age 
  WITH compression = { 
    'sstable_compression' : 'DeflateCompressor', 
    'chunk_length_kb' : 64
  }
  AND compaction = {
    'class' : 'SizeTieredCompactionStrategy', 
    'max_threshold' : 64
  };

Changing caching

You can create and change caching properties using a property map.

This example changes the keys property to NONE (the default is ALL) and changes the rows_per_partition property to 15.

ALTER MATERIALIZED VIEW cycling.cyclist_by_age 
WITH caching = { 
  'keys' : 'NONE', 
  'rows_per_partition' : '15'
};

Viewing current materialized view properties

Use DESCRIBE MATERIALIZED VIEW to see all current properties.

DESCRIBE MATERIALIZED VIEW cycling.cyclist_by_age;

Results

CREATE MATERIALIZED VIEW cycling.cyclist_by_age AS
    SELECT age, cid, birthday, country, name
    FROM cycling.cyclist_base
    WHERE age IS NOT NULL AND cid IS NOT NULL
    PRIMARY KEY (age, cid)
    WITH CLUSTERING ORDER BY (cid ASC)
    AND bloom_filter_fp_chance = 0.01
    AND caching = {'keys': 'ALL', 'rows_per_partition': '100'}
    AND comment = 'Based on table cyclist_base'
    AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}
    AND compression = {'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor'}
    AND crc_check_chance = 1.0
    AND dclocal_read_repair_chance = 0.1
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.0
    AND speculative_retry = '99PERCENTILE';