Can you compare dates in MySQL?

MySQL has the ability to compare two different dates written as a string expression. When you need to compare dates between a date column and an arbitrary date, you can use the DATE() function to extract the date part from your column and compare it with a string that represents your desired date.

Should I index column date?

Is it a good idea to have a index on the Timestamp column? Yes, it is generally a good idea to have an index on a field used in a query criteria. This is really useful when there are a large number of documents (e.g., a million) in the collection. The index will be used to run the query fast.

Can we create index on datetime 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.

Can we create index on date column in SQL Server?

we solved it by creating index on datetime column . yes , cluster index will give better performance over non cluster indexes because ultimately non cluster index use cluster indexes internally .

Which columns are not good for indexing?

If you create an index such as INDEX(first_name, last_name), don’t create INDEX(first_name). However, “index prefix” or “multi-columns index” is not recommended in all search cases. Use the NOT NULL attribute for those columns in which you consider the indexing, so that NULL values will never be stored.

Which columns should be indexed in MySQL?

You should have indexes on all the columns used in the JOIN clauses. i.e, columns on each side of ON clause of a join must be indexed.

What is index cardinality MySQL?

Index cardinality refers to the uniqueness of values stored in a specified column within an index. MySQL generates the index cardinality based on statistics stored as integers, therefore, the value may not be necessarily exact.

What is Sargable query?

In relational databases, a condition (or predicate) in a query is said to be sargable if the DBMS engine can take advantage of an index to speed up the execution of the query. The term is derived from a contraction of Search ARGument ABLE.