Expression index
An expression index, also known as a function based index, is a database index that is built on a generic expression, rather than one or more columns. This allows indexes to be defined for common query conditions that depend on data in a table, but are not actually stored in that table. A common use for an expression index is to support case-insensitive searching or constraints. For example, if a web site wants to make user names case-insensitive, but still preserve the case as originally entered by the user, an index can be created on the lower-case representation of the user name:
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Expression index
An expression index, also known as a function based index, is a database index that is built on a generic expression, rather than one or more columns. This allows indexes to be defined for common query conditions that depend on data in a table, but are not actually stored in that table. A common use for an expression index is to support case-insensitive searching or constraints. For example, if a web site wants to make user names case-insensitive, but still preserve the case as originally entered by the user, an index can be created on the lower-case representation of the user name:
has abstract
An expression index, also know ...... ast_name ) = lower( 'Smith' );
@en
式インデックス (英: expression index) ...... user_name) = lower('Decibel');
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724,892,099
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An expression index, also know ...... presentation of the user name:
@en
式インデックス (英: expression index) ...... user_name) = lower('Decibel');
@ja
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Expression index
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式インデックス
@ja