Search MySQL like?

sphinxsearch.com/not?

Why do You seek links? Maybe it's worth of links to allocate the information which will be searched and stored in a single field index on the field?

what data in the data?

speed will greatly depend on whether the field DATA index is created

The first thing to do for such a volume is to cut the table on any basis, because 500K records per day — a lot. I remember there was a table with 4 billion entries, then all entries from this table was very nerdy
Second, you did not explain what kind of data contained in the DATA. Can do fulltext (provide show create table). If the data is large enough, as pointed out in the first answer, the Sphinx