TRUNCATE

Removes all data from the specified table immediately and irreversibly. By extension, this also removes all data from any materialized views based on the truncated table.

Node responsiveness

TRUNCATE requires responses from all nodes. When you run TRUNCATE, the database sends a request to all nodes to delete the SSTables for the truncated table. Deletion waits until all nodes respond. If any nodes are down or unresponsive, the command fails entirely and outputs an error like Unable to complete request: one or more nodes were unavailable.

To ensure nodes are up and responsive before running TRUNCATE, do the following:

Use the CQL shell CONSISTENCY command to set the consistency level to ALL.

Although the consistency level isn’t directly relevant to TRUNCATE, it ensures that all nodes are responsive. You can test node responsiveness with a SELECT statement. If any nodes are down, the query fails because it didn’t receive a response from all nodes.
Use nodetool status or some other tool to make sure all nodes are up and healthy.

Synopsis

TRUNCATE [ TABLE ] [<keyspace_name>.]<table_name> ;

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.
`<<datatype1>,<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.

Options

TRUNCATE TABLE: The command to drop all rows from a table.

The short form is TRUNCATE.
keyspace_name: Optional. Name of the keyspace containing the table to truncate. If not specified, the current keyspace is used.
table_name: Name of the table to truncate.

On Linux systems, object names, such as keyspace and table names, are case-sensitive. CQL converts object names to lowercase unless enclosed in double quotation marks.

Examples

Run the TRUNCATE command with the name of the table to truncate:
```
TRUNCATE country_flag;
```
If you have multiple tables with the same name in different keyspaces, specify the keyspace to avoid ambiguity:
```
TRUNCATE cycling.country_flag;
```
If needed, wait for the TRUNCATE operation to complete on all nodes.

Because TRUNCATE waits for a response from all nodes, it can take some time to complete in clusters with slow nodes, many nodes, or geographically distant datacenters. If the operation fails, see Node responsiveness.

Use a SELECT statement to verify that the table is empty.

SELECT * FROM cycling.country_flag;

 country | cyclist_name | flag
---------+--------------+------


(0 rows)

TRUNCATE

Node responsiveness

Synopsis

Options

Examples

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