In this example, Oracle converted all values in the last_name column to uppercase and stored these results in the members_last_name_fi index. Now, if you find members by the last name, the query optimizer will
example, 2-11 FILE_DATASTORE system-defined preference, 2-70 filter formats supported, B-5 FILTER procedure, 7-2 example, 7-4 in-memory example, 7-3 result table, A-8 filter table structure, A-8 filter types, 2-23 filtering to plain text, 7-13 to plain text and...
locking in cache, 11-14 message queuing, 16-5 methods of, 1-54, 11-4 method calls, 12-3 PL/SQL, 11-13 purchase order example, 11-2, 11-5 mutually dependent, 12-13 object views, 8-14 Oracle type translator, 11-14 purchase order example, 11-2, 11-4 row objects...
Example 13–5 Index Skip Scan Consider, for example, a table employees (sex, employee_id, address) with a composite index on (sex, employee_id). Splitting this composite index would result in two logical subindexes, one for M and one for F. For this example, suppose you have the follo...
CREATE INDEX ExampleThe 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 ...
Asshown in Example2-1, a unique key constraint exists on the email column of the hr.employeestable. The relevant part of the statement is as follows: CREATE TABLE employees ( ... ,email VARCHAR2(25) CONSTRAINT emp_email_nn NOT NULL ... ...
To removeINDEXfrom a table, we can use theDROP INDEXcommand. For example, SQL Server DROPINDEXColleges.college_index; PostgreSQL, Oracle DROPINDEXcollege_index; MySQL ALTERTABLECollegesDROPINDEXcollege_index; Here, the SQL command removes an index namedcollege_indexfrom theCollegestable. ...
specified table. If the statement uses an index range scan, then Oracle scans the index entries in ascending order of their indexed values. In a partitioned index, the results are in ascending order within each partition.Each parameter serves the same purpose as in "INDEX Hint". For example...
2 | ORACLE INDEX COMPRESSION Index Key Compression Index Key Compression, also referred to as Index Prefix Compression, is perhaps one of the oldest compression features within the Oracle Database, released with Oracle Database 8.1.3 (before Basic Table Compression in 9.2). It has the potential...
New in Django 2.2. The names of thePostgreSQL operator classesto use for this index. If you require a custom operator class, you must provide one for each field in the index. For example,GinIndex(name='json_index',fields=['jsonfield'],opclasses=['jsonb_path_ops'])creates a gin index...