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Another option (relevant for version 5.7.3 and above) is to create a generated/virtual column based on the datetime column, then index it. CREATE TABLE `table` ( `my_datetime` datetime NOT NULL, `my_date` varchar(12) GENERATED ALWAYS AS (DATE(`my_datetime`)) STORED, KEY `my_idx` (`my_date`) ) ENGINE=InnoDB;
4 wrz 2018 · In your case you could try using two single column index .. create index ani_idx1 on call_data_report(ANI); create index ani_idx2 on call_data_report(DNIS); because usinge OR the second key of your composite index ani_idx DNIS is not used ..
MySQL can create composite indexes (that is, indexes on multiple columns). An index may consist of up to 16 columns. For certain data types, you can index a prefix of the column (see Section 10.3.5, “Column Indexes”).
30 sty 2023 · If the table has a multiple-column index, any leftmost prefix of the index can be used by the optimizer to look up rows. For example, if you have a three-column index on (name,email,creation_date), you have indexed search capabilities on (name), (name, email), and (name,email,creation_date). Multiple-Column Indexes
MySQL allows you to create a composite index that consists of up to 16 columns. A composite index is also known as a multiple-column index. The query optimizer uses the composite indexes for queries that test all columns in the index, or queries that test the first columns, the first two columns, and so on.
The SQL statement below creates an index named "idx_lastname" on the "LastName" column in the "Persons" table: CREATE INDEX idx_lastname. ON Persons (LastName); If you want to create an index on a combination of columns, you can list the column names within the parentheses, separated by commas: CREATE INDEX idx_pname.
1 wrz 2016 · A better way to do the operation is this. WHERE x >= '2016-09-01' AND x < '2016-09-01' + INTERVAL 1 DAY. This selects a range of values of x lying anywhere on the day in question, up until but not including (hence <) midnight on the next day. If the table has an index on the x column, then the database server can perform a range scan on the index.
