what is – Page 60

Understanding INFORMATION_SCHEMA in SQL

June 28, 2023 by Ian

Behind every well-structured and organised SQL database lies a treasure trove of information called metadata. Metadata is data that provides information about other data. In relational database management systems, this metadata can typically include information like the names of databases, tables, columns, the data type of a column, access privileges, and much more.

The SQL standard provides a collection of tables/views that allow us to view metadata about the objects in the database. The SQL standard refers to this as the information schema and calls it INFORMATION_SCHEMA.

Using the sys.format_path() Function to Dynamically Replace a Subpath with its Equivalent System Variable in MySQL

June 26, 2023 by Ian

In MySQL, the sys.format_path() function is a stored function in the sys schema. It accepts a path name, and returns the modified path name after replacing subpaths that match the values of certain system variables.

So we can use the function to dynamically replace part or all of our path with a system variable that matches that path segment.

Understanding the sys.extract_table_from_file_name() Function in MySQL

June 25, 2023 by Ian

In MySQL, the sys.extract_table_from_file_name() function is a stored function in the sys schema.

It accepts a path name, and returns the path component that represents the table name.

How to Use the sys.ps_is_account_enabled() Function in MySQL

June 24, 2023 by Ian

In MySQL, we can use the sys.ps_is_account_enabled() function to check whether Performance Schema instrumentation for a given account is enabled.

The function returns YES or NO, depending on whether or not the instrumentation for the given account is enabled.

Using the sys.ps_thread_account() Function to Get the Account for a Given Thread ID in MySQL

June 29, 2023June 23, 2023 by Ian

In MySQL, the sys.ps_thread_account() function returns the account associated with a given thread ID. It returns the account in the form user_name@host_name.

Understanding the sys.ps_is_instrument_default_enabled() Function in MySQL

June 28, 2023June 22, 2023 by Ian

In MySQL, we can use the sys.ps_is_instrument_default_enabled() function to check whether a given Performance Schema instrument is enabled by default.

The function returns YES or NO, depending on whether the instrument is enabled by default.

Understanding the sys.ps_is_instrument_default_timed() Function in MySQL

June 28, 2023June 19, 2023 by Ian

In MySQL, we can use the sys.ps_is_instrument_default_timed() function to check whether a given Performance Schema instrument is timed by default.

The function returns YES or NO, depending on whether the instrument is timed by default.

Understanding the sys.ps_is_thread_instrumented() Function in MySQL

June 28, 2023June 18, 2023 by Ian

In MySQL, we can use the sys.ps_is_thread_instrumented() function to check whether Performance Schema instrumentation for a given connection ID is enabled.

The function returns YES or NO, depending on whether the instrumentation is enabled for the given connection. It can also return UNKNOWN if the connection ID is unknown, and NULL if the connection ID is NULL.

Understanding the sys.version_patch() Function in MySQL

June 28, 2023June 17, 2023 by Ian

In MySQL, we can use the sys.version_patch() function to return the patch release version of the MySQL server.

For example, if we’re using MySQL 8.0.33, sys.version_patch() returns 33.

Understanding the sys.version_minor() Function in MySQL

June 28, 2023June 17, 2023 by Ian

In MySQL, we can use the sys.version_minor() function to return the minor release version of the MySQL server.