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Can we create index on date column?
Yes, it can use it to do a range scan in the query you suggested. Index will improve performance. With index – it will create sorted “array”, so it will be able to use binary search to find where today+3 starts and just scan all further rows of this array instead of full scan.
Should you index timestamps?
You should definitely use an index. MySQL has no clue what order those timestamps are in, and in order to find a record for a given timestamp (or timestamp range) it needs to look through every single record.
Should you index every column?
Yes, having an index on every column might improve read performance. It’ll certainly slow write performance ( INSERT , UPDATE and DELETE ), though that’s not a concern for your DB.
Can we create index on date column in MySQL?
This makes your datetime column an excellent candidate for an index if you are going to be using it in conditions frequently in queries. If your only condition is BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 30 DAY) and you have no other index in the condition, MySQL will have to do a full table scan on every query.
What is clustered index?
A clustered index is a special type of index that reorders the way records in the table are physically stored. Therefore table can have only one clustered index. The leaf nodes of a clustered index contain the data pages.
Is it possible to create Index on just the date part of a datetime field?
>> is it possible to create an index on a DATETIME field [sic] that just looks at the date part,<< The first problem is that you don’t think in SQL. Columns are not anything like fields.You are still writing 1950’s COBOL, which does have fields. Columns are scalars, not made up of parts.
Which is better date column or INT column?
Date columns are larger causing all of the indexes to be larger. Date columns are not usually unique requiring an additional hidden column in the index called a uniquifer that will increase the size of all of the indexes even more. Pros to using the date column
Which is a better clustered index int or date?
The other day I was answering a question about clustered indexes and it lead indirectly to a twitter conversation on whether a date or int column was better as a clustered index. My contention is that a date column (if it is appropriate and will be useful) is a better clustered index than the int column.
Are there any cons to using a date column?
Cons to using the date column Date columns are larger causing all of the indexes to be larger. Date columns are not usually unique requiring an additional hidden column in the index called a uniquifer that will increase the size of all of the indexes even more.