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CREATE INDEX defines a new index on an existing table.
Syntax
CREATE [ UNIQUE ] INDEX index_name ON [ MEMORY ] table_name
| ( column_name [ ASC | DESC ] [ CASE | NOCASE ] [, ... ] )
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Description
CREATE INDEX constructs an index index_name on the specified table. Indexes are primarily used to enhance database performance (though inappropriate use will result in slower performance).
Multi-column indexes are allowed.
UNIQUE
| Causes the database engine to check for duplicate values in the table when the index is created (if data already exist) and each time data is added. Attempts to insert or update data which would result in duplicate entries will generate an error.
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index_name
| The name of an index to be created.
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MEMORY
| If MEMORY keyword is specified before the table_name then an in-memory table is referenced, not a disk one.
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table_name
| The name of the table to be removed.
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column_name
| The name of a column to be indexed.
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ASC
| The column will be indexed with ascending sort order. This is the default.
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DESC
| The column will be indexed with descending sort order.
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CASE
| The column will be indexed with case-sensitive sort order. This is the default.
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NOCASE
| The column will be indexed with case-insensitive sort order.
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Example:
| CREATE UNIQUE INDEX idxUniqueName ON developers (name DESC NOCASE, code);
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