SQL getting started Tutorial: SQL CREATE INDEX syntax

SQL getting started Tutorial: SQL CREATE INDEX syntax

The table used to create the index in the create index statement.

Indicators allow database applications to quickly find data without reading the entire table.

Metrics
This index can be created in a table to find data faster and more effective.

Users cannot see indicators. They are only used to speed up search/query.

Note: It takes more time to update Tables and indexes than to update a table (because indicators still need to be updated ). Therefore, you should create only index columns (tables) and search them frequently.
SQL syntax for creating Indexes
Create an index table. Repeated values are allowed:

Create index index_name
ON table_name (column_name)

SQL CREATE UNIQUE INDEX syntax creates a UNIQUE INDEX seat. Duplicate values are not allowed: create unique index index_name
ON table_name (column_name) SQL create index instance. The SQL statement is as follows: CREATE an INDEX named "PIndex". The "last name" column is in the "p" table: create index PIndex
ON Persons (LastName) If you want to CREATE an indexed column, you can list the column names in brackets separated by commas (,): create index PIndex
ON Persons (LastName, FirstName)