Source

File: wp-includes/wp-db.php

public function log_query( $query, $query_time, $query_callstack, $query_start, $query_data ) {
		/**
		 * Filters the custom query data being logged.
		 *
		 * Caution should be used when modifying any of this data, it is recommended that any additional
		 * information you need to store about a query be added as a new associative entry to the fourth
		 * element $query_data.
		 *
		 * @since 5.3.0
		 *
		 * @param array  $query_data      Custom query data.
		 * @param string $query           The query's SQL.
		 * @param float  $query_time      Total time spent on the query, in seconds.
		 * @param string $query_callstack Comma-separated list of the calling functions.
		 * @param float  $query_start     Unix timestamp of the time at the start of the query.
		 */
		$query_data = apply_filters( 'log_query_custom_data', $query_data, $query, $query_time, $query_callstack, $query_start );

		$this->queries[] = array(
			$query,
			$query_time,
			$query_callstack,
			$query_start,
			$query_data,
		);
	}