How do you properly index a table?

By Blog

How do you properly index a table?

Top 10 Steps to Building Useful Database Indexes

  1. Index by workload, not by table.
  2. Index most-heavily used queries.
  3. Index important queries.
  4. Index to avoid sorting (GROUP BY, ORDER BY)
  5. Create indexes for uniqueness (PK, U)
  6. Create indexes for foreign keys.
  7. Consider adding columns for index only access.

Which fields should you index in a table?

Primary key columns are typically great for indexing because they are unique and are often used to lookup rows. Any column that is going to be regularly used to extract data from the table should be indexed.

Can you use an index in MySQL order by column?

However, MySQL cannot use an index for mixed ASC,DESC order by ( SELECT * FROM foo ORDER BY bar ASC, pants DESC ). Sharing your query and CREATE TABLE statement would help us answer your question more specifically. For hints on how to optimize ORDER BY clauses: http://dev.mysql.com/doc/refman/5.1/en/order-by-optimization.html

How to use the ORDER BY clause in SQL?

The SQL ORDER BY Clause is used to set the result-set a query by one or more columns. The ORDER BY SQL keyword sorts the records by default in ascending order. therefore, to sort the records in descending order, then you can use the DESC keyword. . Therefore, if you want to specify the order, then you can use the ORDER BY clause.

How to specify the Order of rows in a table?

To specify exactly the order of rows in the result set, you add use an ORDER BY clause in the SELECT statement as follows: SELECT column1, column2 FROM table_name ORDER BY column1 ASC , column2 DESC; In this syntax, the ORDER BY clause appears after the FROM clause. In case the SELECT statement contains a WHERE clause.

When to use an index on the sort column?

An index on the sort column may be used if you are selecting the entire table though. Like select from product order by name; Again, your milage may vary. This is speculation based off past experience. Just my two cents. The other answer is great but doesn’t address the idea of removing the one and only clustered index.

However, MySQL cannot use an index for mixed ASC,DESC order by ( SELECT * FROM foo ORDER BY bar ASC, pants DESC ). Sharing your query and CREATE TABLE statement would help us answer your question more specifically. For hints on how to optimize ORDER BY clauses: http://dev.mysql.com/doc/refman/5.1/en/order-by-optimization.html

How to use index and order by in select statements?

Index and Order By in Select Statements. Use the order by keyword in your select statements to order the data that’s returned. Use the index hint keywords to specify that a particular index should be used in the query and to sort the selected records as defined by the index. Indexes optimize the selection of records.

When to use the ORDER BY clause in MySQL?

Order by clause is used with the SELECT query to arrange result in a specific order. You just need to separate your column names by the comma (,) when you are specifying multiple columns. Yogesh Singh is a web developer and founder of makitweb .

An index on the sort column may be used if you are selecting the entire table though. Like select from product order by name; Again, your milage may vary. This is speculation based off past experience. Just my two cents. The other answer is great but doesn’t address the idea of removing the one and only clustered index.