I have the following performance problem with a select statement. The table is about 651.000 entries. The statement looks like:
SELECT SQL_CACHE ID, filename,
FORCE INDEX ( ID_2 )
WHERE ID > 90000
ORDER BY page_rank DESC
LIMIT 245 , 15
The index ID_2 is:
Name:ID_2, Typ: INDEX, Cardinality: 651002, Fields: ID, page_rank
The request last very long, about 45 secs. The EXPLAIn shows the following:
Extra: Using where; Using filesort
What do I wrong? Why does mysql run through the hole table? Why “Using filesort” even I use the index ID_2??
Please help! Thank in advance!