SERIAL CONSISTENCY
Sets the serial consistency for a lightweight transaction (LWT).
Sets the serial consistency for lightweight transactions (LWTs). A LWT contains an IF EXISTS or IF NOT EXISTS clause. See Data consistency in the documentation.
When using a LWT:
- Levels must be set for SERIAL CONSISTENCY and CONSISTENCY.
- SERIAL CONSISTENCY can be set to SERIAL or LOCAL_SERIAL.
- CONSISTENCY cannot be set to SERIAL or LOCAL_SERIAL.
Synopsis
SERIAL CONSISTENCY [ consistency_level ]
Syntax conventions | Description |
---|---|
UPPERCASE | Literal keyword. |
Lowercase | Not literal. |
Italics |
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. |
- consistency_level
-
Consistency level. Can be set to
SERIAL
orLOCAL_SERIAL
.
Examples
Show the current SERIAL CONSISTENCY
status:
SERIAL CONSISTENCY
Current serial consistency level set to SERIAL.
SERIAL CONSISTENCY LOCAL_SERIAL
Serial consistency level set to LOCAL_SERIAL.
When using a LWT, you must have levels set for CONSISTENCY and SERIAL CONSISTENCY.
For example, write data using a LWT with IF NOT EXISTS to examine if the row already exists before performing the write:
CONSISTENCY ONE SERIAL CONSISTENCY SERIAL INSERT INTO cycling.cyclist_name ( id, firstname, lastname ) VALUES ( e7ae5cf3-d358-4d99-b900-85902fda9bb0, 'Alex', 'FRAME' ) IF NOT EXISTS;
If the record already exists then the write is not applied, as shown in the following result:
[applied] | id | firstname | lastname
-----------+--------------------------------------+-----------+----------
False | e7ae5cf3-d358-4d99-b900-85902fda9bb0 | Alex | FRAME