In MySQL, the sys.extract_schema_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 schema name.
This enables us to get the schema from a given file path.
functions
3 JSON Utility Functions in MySQL
MySQL provides us with a few utility functions that act on JSON values, or strings that can be parsed as JSON values.
Below are three JSON utility functions that we can use for such tasks.
Using the sys.format_statement() Function in MySQL to Truncate a SQL Statement
In MySQL, the sys.format_statement() system function reduces the length of a given string/SQL statement to the length stored in the statement_truncate_len configuration option.
This function can be handy for truncating potentially long SQL statements retrieved from Performance Schema tables into a more suitable length (64 characters by default).
Understanding the PS_THREAD_ID() Function in MySQL
In MySQL, we can use the PS_THREAD_ID() function to get the Performance Schema thread ID assigned to a given connection ID. This can be useful whenever we use a function that takes the thread ID as its parameter, but we only know the connection ID.
If no thread ID exists for the connection, then NULL is returned.
The built-in PS_THREAD_ID() function does the same thing as the now deprecated sys.ps_thread_id() function. Therefore, we can call the function without needing to qualify it with sys or making sys our current schema.
Using the sys.format_path() Function to Dynamically Replace a Subpath with its Equivalent System Variable in MySQL
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
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
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
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
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
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.