(PHP 4 >= 4.0.6)mysql_unbuffered_query -- Send an SQL query to MySQL, without fetching and buffering the result rows
Descriptionresource mysql_unbuffered_query ( string query [, resource link_identifier])
mysql_unbuffered_query() sends a SQL query query to MySQL, without fetching and buffering the result rows automatically, as mysql_query() does. On the one hand, this saves a considerable amount of memory with SQL queries that produce large result sets. On the other hand, you can start working on the result set immediately after the first row has been retrieved: you don't have to wait until the complete SQL query has been performed. When using multiple DB-connects, you have to specify the optional parameter link_identifier.
Note: The benefits of mysql_unbuffered_query() come at a cost: You cannot use mysql_num_rows() and mysql_data_seek() on a result set returned from mysql_unbuffered_query(). You also have to fetch all result rows from an unbuffered SQL query, before you can send a new SQL query to MySQL.
See also mysql_query().