OnlineIndex
database parameter
Description
Specifies that the Database painter should use the ONLINE keyword
when you create or drop an index on a table so that the index can be
created or dropped without locking the table.
When to specify OnlineIndex
You must specify the OnlineIndex parameter before connecting to
the database.
Applies to
I10 Informix
Syntax
|
1 |
OnlineIndex='value' |
|
Parameter |
Description |
|---|---|
|
value |
Specifies that the Database painter should use the
|
Default value
OnlineIndex=0
Usage
In IDS 10.0 and later, the SQL syntax of CREATE INDEX and DROP
INDEX supports the ONLINE keyword to create or drop an index in an
online environment where the database and its tables are continuously
available. When you use the ONLINE keyword to create or drop an index,
data definition language (DDL) operations execute without applying an
exclusive lock on the table on which the specified index is
defined.
If you use CREATE INDEX ONLINE to create an index on a table that
other users are accessing, the index is not available until no users are
updating the table. If you issue DROP INDEX ONLINE to drop an index, no
users can reference the index, but concurrent data manipulation language
(DML) operations can use the index until the operations terminate.
Dropping the index is deferred until no users are using the
index.
You can set the OnlineIndex static DBParm on the System tab page
in the Database Profile Setup dialog box for I10 connections to specify
that the Database painter should use the ONLINE keyword when you create
or drop an index.
Clustered index not supported
You cannot create a clustered index using online mode because it
is not supported by IDS.
Examples
To specify that the Database painter use the ONLINE keyword when
you create or drop an index in the Database painter:
-
Database profile
Select the Create or Drop Non-Clustered Indexes Without
Dropping Tables check box on the System page in the Database Profile
Setup dialog box. -
Application
Type the following in code:
1SQLCA.DBParm="OnlineIndex=1"