3 ms·
Indeed! An index can be the difference between a 2-5minute full table scan and a subsecond query.
by voiper1 10y ago
Indeed! An index can be the difference between a 2-5minute full table scan and a subsecond query.
- Sami_Lehtinen 10y agoDepends from your disk system and data set size ... It can also mean 2-5 hours or days versus subsecond query. Try having 6 TB database with integer column. Then select just one row from it. Either it's indexed or not. You don't need to explain that, if query ends up taking forever it wasn't indexed.