Oracle7 Server Concepts
Parameter Files
To start an instance, Oracle must read a parameter file.A parameter file is a text file containing a list of instance configuration parameters. You set these parameters to particular values and to initialize many of the memory and process settings of an Oracle instance. Among other things, the parameters of this file tell Oracle the following:
- the name of the database for which to start up an instance
- what to do with filled online redo log files
- the names of private rollback segments in the database
An Example of a Parameter File
The following is an example of a typical parameter file:
db_block_buffers = 550
db_name = ORA7PROD
db_domain = US.ACME.COM
#
license_max_users = 64
#
control_files = filename1, filename2
#
log_archive_dest = c:\logarch
log_archive_format = arch%S.ora
log_archive_start = TRUE
log_buffer = 64512
log_checkpoint_interval = 256000
# rollback_segments = rs_one, rs_two
Oracle treats string literals defined for National Language Support (NLS) parameters in the file as if they are in the database character set.
Most parameters belong to one of the following groups:
- parameters that name things (such as files)
- parameters that set limits (such as maximums)
- parameters affecting capacity, called variable parameters (such as the DB_BLOCK_BUFFERS parameter, which specifies the number of data blocks to allocate in the computer's memory for the SGA)
Changing Parameter Values
The database administrator can adjust variable parameters to improve the performance of a database system. Exactly which parameters most affect a system is a function of numerous database characteristics and variables.