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A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time said table is accessed.
Creating complex queries using query-by-example (QBE) Searching globally in a database or a subset of it; Transforming stored data into any format using a set of predefined functions, like displaying BLOB-data as image or download-link; Live charts to monitor MySQL server activity like connections, processes, CPU/memory usage, etc.
MySQL provides an enumerated type ENUM with allowable values specified as strings when a table is created. The values are stored as numeric indices with the empty string stored as 0, the first string value stored as 1, the second string value stored as 2, etc. Values can be stored and retrieved as numeric indexes or string values. [15] Example:
MySQL uses a .frm file to store the definition of the table, but this file is not a part of the MyISAM engine; instead it is a part of the server. The data file has a .MYD (MYData) extension. The index file has a .MYI (MYIndex) extension. The index file, if lost, can always be recreated by recreating indexes.
For this example it is assumed that each book has only one author. A table that conforms to the relational model has a primary key which uniquely identifies a row. In our example, the primary key is a composite key of {Title, Format} (indicated by the underlining):
Upload PDF to a free online PDF-to-Excel site. For example; here. Download the Excel file. Open it in freeware LibreOffice Calc or another spreadsheet program. If you just want one table from a long Excel page, you can select that table from the Calc page. Then copy the table to a new page in Calc. Edit and move columns and rows in Calc.
The individual statements of the statement string are separated by semicolon. Then, all result sets returned by the executed statements must be fetched. The MySQL server allows having statements that do return result sets and statements that do not return result sets in one multiple statement. See examples in [7]
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: CREATE INDEX users__last_name_lower ON users( lower( last_name ) ); That will create a unique index on "lower(last_name)".