READ_ONLY_OPEN_DELAYED

Property	Description
Parameter type	Boolean
Default value	false
Modifiable	No
Range of values	true | false

READ_ONLY_OPEN_DELAYED determines when datafiles in read-only tablespaces are accessed.

Values:

• true

The datafiles are accessed for the first time only when an attempt is made to read data stored within them.

• false

The datafiles are accessed at database open time.

You can use this parameter to speed up some operations (primarily opening the database) for very large databases when substantial portions of the database are stored in read-only tablespaces. Consider setting this parameter to true for such databases, especially if portions of the read-only data are stored on slow-access devices or hierarchical storage.

Note:

1. See Oracle Database Administrator's Guide for information on the consequences of delaying access of datafiles in read-only tablespaces.

2. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter

where upper(name) = 'READ_ONLY_OPEN_DELAYED';

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE		ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
read_only_open_delayed	FALSE	TRUE	FALSE	FALSE	FALSE		FALSE	if TRUE delay opening of read only files until first access

Oracle initializatoin parameters