Appendix: Miscellaneous Guidelines and Additional Resources
Learn the notations used for CQL command syntax, basic tips for CQL query execution in the terminal widget, practical advice on optimizing Cassandra's performance, and find links to external resources.
CQL syntax conventions
The following table displays the syntax conventions used throughout the course. Please note that [ ] , ( ) , or | are for illustration purposes only and should not be included in CQL statements.
CQL syntax notation
Syntax | Description |
UPPERCASE | CQL KEYWORD |
Italics | Variable to contain user-defined value |
| Optional. Square brackets enclose optional command elements. |
| Group. Parenthesis enclose a group of elements. |
| OR. Vertical bar separates alternatives. |
| Repeatable. An ellipsis ( |
Guidelines for executing CQL statements in the terminal
Below is a list of basic tips and insights for CQL statement execution in the terminal:
CQL statements end with a semicolon
;In the absence of a semicolon at the end of a query, the query is not executed as the system waits for additional input.In Cassandra, no response indicates the successful execution of the statement. Only errors are reported.
The terminal widget is nonpersistent. Keyspaces, tables, etc., created in one terminal session are not saved and, therefore, are inaccessible in other terminal sessions.
When a keyspace name in the
CREATE KEYSPACEstatement is specified without quotes, Cassandra forces the keyspace name to be lowercase.
Guidelines for improved Cassandra's performance
All guidelines and good practices listed below have been covered in the related lessons. This list simply serves as a compilation.
Design data model for query patterns: Analyze the application's query patterns. Design the data model based on the specific queries that need to be executed. Use ...