Timestamp indexing

Question

If I have a table with columns: item_id, user_id, vote, date what columns should I put the index on considering:

1. I'll need to fetch votes by date for time ranges and

2. there cannot be more than one vote for each item by a user.

Should the index be sorted ASC or DESC if I want to fetch dates that are more recent?

Answer 1

PRIMARY:item_id,user_id

INDEX: date

Sort DESC for latest first

Note: I assume you are storing date as UNIX TIMESTAMP (From your question title Timestamp Indexing)

Answer 2

You can try the following:

CREATE INDEX mytime_index ON myTable (user_id, date);

You can't set asc and desc at index level as it's bydefault on asc .

Check this out-------------- Quoted from mysql website create indices

An index_col_name specification can end with ASC or DESC. These keywords are permitted for future extensions for specifying ascending or descending index value storage. Currently, they are parsed but ignored; index values are always stored in ascending order