To start a database service in Unix or Linux, you will need to use the appropriate command for the database software that you are using. Different database systems have different commands and options for starting, stopping, and managing the database service.
Here are some examples of how to start a database service in Unix or Linux for some common database systems:
mysqld
This will start the MySQL server with the default options. Consult the documentation of the "mysqld" command for more information on the available options and their meanings.
pg_ctl start -D /path/to/data/directory
This will start the PostgreSQL server with the specified data directory. Consult the documentation of the "pg_ctl" command for more information on the available options and their meanings.
dbstart $ORACLE_HOME
This will start the Oracle Database server with the specified Oracle home directory. Consult the documentation of the "dbstart" and "dbshut" scripts for more information on the available options and their meanings.
With these examples, you should be able to start a database service in Unix or Linux using the appropriate command for your database software. Consult the documentation of your database system for more information on how to start, stop, and manage the database service.