Mysql + big tables = slow queries?

Question

I have some performance issues with a big table on Mysql : The table has got 38 million rows, its size is 3GB. I want to select by testing 2 columns : I tried many indexing

Answer 1

The main thing you can do is to add indexes.

Any time that you use a column in a where clause, make sure it has an index. There isn't one on your created column.

The multi-index including the created column in essence is NOT an index on created since created isn't first in the multi-index.

When using multi-indexes, you should almost always put the column with higher cardinality first. So, having the indexes be: (created, word_id), (word_id) would give you a significant boost.