Database Management¶

Database Users¶

A CUBRID database user can have members with the same authorization. If authorization A is granted to a user, the same authorization is also granted to all members belonging to the user. A database user and its members are called a "group."; a user who has no members is called a "user."

CUBRID provides DBA and PUBLIC users by default.

• DBA can access every object in the database, that is, it has authorization at the highest level. Only DBA has sufficient authorization to add, alter and delete the database users.
• All users including DBA are members of PUBLIC. Therefore, all database users have the authorization granted to PUBLIC . For example, if authorization B is added to PUBLIC group, all database members will automatically have the B authorization.

databases.txt File¶

CUBRID stores information on the locations of all existing databases in the databases.txt file. This file is called the "database location file". A database location file is used when CUBRID executes utilities for creating, renaming, deleting or replicating databases; it is also used when CUBRID runs each database. By default, this file is located in the databases directory under the installation directory. The directory is located through the environment variable CUBRID_DATABASES.

db_name db_directory server_host logfile_directory

The format of each line of a database location file is the same as defined by the above syntax; it contains information on the database name, database path, server host and the path to the log files. The following example shows how to check the contents of a database location file.

% more databases.txt

dist_testdb /home1/user/CUBRID/bin d85007 /home1/user/CUBRID/bin
dist_demodb /home1/user/CUBRID/bin d85007 /home1/user/CUBRID/bin
testdb /home1/user/CUBRID/databases/testdb d85007 /home1/user/CUBRID/databases/testdb
demodb /home1/user/CUBRID/databases/demodb d85007 /home1/user/CUBRID/databases/demodb

By default, the database location file is stored in the databases directory under the installation directory. You can change the default directory by modifying the value of the CUBRID_DATABASES environment variable. The path to the database location file must be valid so that the cubrid utility for database management can access the file properly. You must enter the directory path correctly and check if you have write permission on the file. The following example shows how to check the value configured in the CUBRID_DATABASES environment variable.

% set | grep CUBRID_DATABASES
CUBRID_DATABASES=/home1/user/CUBRID/databases

An error occurs if an invalid directory path is set in the CUBRID_DATABASES environment variable. If the directory path is valid but the database location file does not exist, a new location information file is created. If the CUBRID_DATABASES environment variable has not been configured at all, CUBRID retrieves the location information file in the current working directory.

Database Volume¶

The volumes of CUBRID database are classified as permanent volume, temporary volume and backup volume.

• In the permanent volumes,
  • there are data volumes, that usually store permanent data, but can also store temporary data.
  • there are log volumes, that can be further classified as: one active log, archive logs and one background archiving log.
• In the temporary volumes, only temporary data is stored.

For more details on volumes, see Database Volume Structure.

The following is an example of files related to the database when testdb database operates.

• Database volume file
  • In the table above, testdb, testdb_perm, testdb_temp, testdb_x003 ~ testdb_x006 are classified as the database volume files.
  • File size is determined by db_volume_size in cubrid.conf or the --db-volume-size option of cubrid createdb and cubrid addvoldb.
  • When database remains out of space, it automatically expands existing volumes and creates new volumes.
• Temporary volume
  • Temporary volumes are usually used to store temporary data. They are automatically created and destroyed by database.
  • File size is determined by db_volume_size in cubrid.conf.
• Log volume file
  • In the above, testdb_lgar_t, testdb_lgar224 and testdb_lgat are classified as the log volume files.
  • File size is determined by log_volume_size in cubrid.conf or the --log-volume-size option of cubrid createdb.