Top 5 Show Commands in CockroachDB

CockroachDB is a distributed SQL database that provides scalability, fault tolerance, and consistency. It is an open-source database that is highly resilient and provides excellent performance, making it an excellent choice for modern applications. One of the essential features of CockroachDB is its powerful SHOW commands that enable users to get insight into the database's internal workings. In this post, we will explore the top five SHOW commands in CockroachDB and their practical applications.

SHOW STATEMENTS and SHOW LOCAL STATEMENTS

The SHOW STATEMENTS command provides a list of all the SQL statements that were recently executed on the cluster. The command also includes information about the statement's execution status, including its execution time and the number of rows it affected. The SHOW LOCAL STATEMENTS command displays the same information but only for the current node.

Example:

SHOW STATEMENTS;

Output:

SHOW FULL TABLE SCANS

The SHOW FULL TABLE SCANS command provides a list of all the table scans that occurred on the cluster. A table scan occurs when the database reads an entire table sequentially instead of using an index. Full table scans are expensive and can lead to poor performance, so it's crucial to monitor them.

Example:

SHOW FULL TABLE SCANS;

Output:

SHOW CREATE (ALL, Database,Schema,Tables)

The SHOW CREATE command provides the SQL statements needed to recreate a particular object in the database. The command supports four options: ALL, Database, Schema, and Tables. The ALL option provides the SQL statements to recreate the entire database. The Database option provides the SQL statements to recreate the database, the Schema option provides the SQL statements to recreate a schema, and the Tables option provides the SQL statements to recreate a table.

Example:

SHOW CREATE TABLE my_table;

Output:

SHOW ALL ZONE CONFIGURATIONS

The SHOW ALL ZONE CONFIGURATIONS command provides information about all the zones configured on the cluster. Zones are used to configure the behavior of the database for particular ranges of data. For example, you can configure a zone to store data in a particular location or replicate data across multiple nodes. This will also provide metadata about the zone such as Garbage collection and lease constraints and preferences.

Example:

SHOW ALL ZONE CONFIGURATIONS;

Output:

SHOW SYSTEM GRANTS adn SHOW GRANTS

The SHOW SYSTEM GRANTS command provides information about the system-level privileges granted to users and roles in the cluster. The command lists all the grants for each user or role, including permissions such as CREATE, DROP, and SELECT. This information is useful for auditing purposes, and it allows you to verify that the right users and roles have the appropriate privileges.

The SHOW GRANTS command in CockroachDB provides a list of privileges granted to a user or role. This command is useful for verifying the privileges of a particular user or role, as well as understanding the security model of the database.

Example:

SHOW GRANTS;

Output: