1. User foo can SELECT from table table1
2. User foo can UPDATE table table1
3. The last GRANT statement results in a syntax error
4. User bar can be SELECTed from table table1
5. User bar can be SELECTed from table table

1. For the log_destination parameter, specify the location of where log  files should be written.
2. By setting logging_collector to on, it is possible to redirect the log message sent to the standard error output to the log file.
3. By setting log_connections to on, a connection attempt from the client to the server is output to the log.
4. By setting logging SQL statements to on, logging SQL statement can be logged.
5. By setting log_line_ prefix to on, various additional information such as log information output time, user name, process ID and so on are output to the log file.

1. Immediately after executing the initdb command, the database cluster will have two template databases, template0 and template1.

2. When you run the createdb command, by default, a copy of template1 is created.

3. When a template database is newly added to the database cluster, its name will automatically be a combination of template and number, such as template2, template3.
4. The contents of the postgres database immediately after executing the initdb command are the same as the template database template1.
5.  The template database template0 should not be updated.

1. Boolean type parameters must be set to true or false in lowercase letters
2. Units of kB, MB, GB can be specified for parameters concerning memory
3. All  setting parameters relating to time are specified in seconds
4. Lines with a # at the beginning is a comment line

5. Parameter settings end with a semicolon like below.  If there is no semicolon, it continues to the next line.

      param1 = val1;

1. A backup performed in the PostgreSQL 9.0 environment using pg_dump can be restored from in the PostgreSQL 9.1 environment.
2. A backup performed in the  PostgreSQL 8.4 environment using  the pg_dumpall command can be restored  in a PostgreSQL 9.0 environment.
3. I must stop the database server process in order to get a backup of the entire database cluster using the pg_dumpall command.
4. A backup of the  PostgreSQL 9.0 environment by directory copy (copying directory of database cluster with tar command etc) may be restored  into a PostgreSQL 9.1 environment.

5. I recovered with the base backup and archive log from a PostgreSQL 8.4 environment  using the point in time recovery (PITR) function, in the environment of a PostgreSQL 9.0 installation.

1. When changing the client side character set to UTF 8, as a SQL statement
        SET client_encoding = utf 8;
   , Or by using the meta command of psql
        \set client_encoding = utf 8
   , The effect is almost the same.

2. SET LOCAL changes only the setting of the client that executed it, but when not using the LOCAL keyword, the settings of all clients connected to the server are changed.
3. Use UNSET to reset what you changed with SET.
4. To check the contents changed by SET, use SHOW.
5. In order to reflect the changed contents in SET, the following must be executed.
        pg_ctl reload  or   pg_ctl restart

1. You can stop a database by executing pg_ctl shutdown from the command line
2. You can stop a database by executing pg_ctl stop from the command line
3. You can stop a database by connecting to it with psql and running the \shutdown meta command

4. If you do not specifically specify at the time of termination, the client connected to the database is automatically disconnected and the running transaction is rolled back

5. Only the administrator user of the database (postgres in many circumstances) can execute to stop a database, it cannot be executed under the authority of the OS administrator user (Linux root)

1. You can not add an object to template0 with CREATE TABLE etc
2. It is not possible to add an object to template1 with CREATE TABLE etc.
3. template0 can not be deleted with DROP DATABASE
4. template1 can not be deleted with DROP DATABASE
5. You can create a new database using the database postgres as a template database

1. Execute the pg_dump command
2. Execute the pg_dumpall command
3. Connect to the database with psql and execute the COPY command
4. Stop the database and copy the whole database cluster using a command attached to the OS, such as the tar command.
5. Use pg_start_backup and pg_stop_backup with a copy of the entire database cluster using the tar command. 

1. Execute the pg_dumpall command.
2. Execute the pg_basebackup command.
3. Stop the database with pg_ctl stop, then create a physical copy of the database cluster with the tar command.

4. Connect to database as administrator user in psql, select pg_start_backup ('label');

   After that, make a physical copy of the database cluster with the tar command.

5. Connect to the database as an administrator user with psql and execute select pg_create_backup ('backup_file');

In order to execute the COPY statement, the database administrator authority is required.

1. It is defined in standard SQL and can be used with many RDBMS, including PostgreSQL.
2. The \copy meta command of psql internally executes the SQL COPY statement.
3. In order to execute the COPY statement, the database administrator authority is required.
4. Input and output files of CSV (Comma Separated Values) format by default.
5. When restoring from a text format backed up by using pg_dump command, the COPY statement is used by default.

1. Whether the user has superuser privileges
2. Whether the user has the authority to newly create a user
3. Whether the user has the authority to create a new table newly
4. User's name
5. User's password

1. Because all data in a table is analyzed, it takes time for large tables.
2. Since an exclusive lock on the table is required, it is not possible to access the data during execution of vacuum.
3. It can be executed by either the ANALYZE command or the VACUUM command.
4. Generally, it is sufficient to execute only once for each table.
5. By optional specification, it can be applied to either  all tables in the database, only specific tables in the database, or only certain columns of a specific table.

1. Automatic vacuum is started regularly and vacuum processing is executed for all tables in the database.
2. Although it is possible to operate the database without executing automatic vacuum, it is strongly  recommended to execute it.
3. When setting to execute automatic vacuum, it is better not to perform manual vacuum processing.
4. Automatic vacuum is activated only when the load on the database is relatively small.
5. Automatic vacuum automatically not only vacuum (VACUUM) but also ANALYZE processing

1. When SELECT current_user; is executed, a list of user names currently connected to the database are displayed.
2. When SELECT current_user; is executed, the user name of the user who executed this SELECT statement is displayed.
3. SELECT current_user ('bob'); allows you to change the user who is running the session.
4. You can use UPDATE current_user = 'bob'; to change the user running the session.
5. An error will occur if you add parentheses, such as SELECT current_user ();. 

1. Available for all relational databases, including PostgreSQL.
2. The specification is part of the ANSI SQL standards.

3. Holds various information about objects in the database.

4. It is defined as a view in the schema named information.

5. Content is equivalent to system catalog.

It can refer to the table test, but it can not update it.

1. It can update the table test, but it can not reference it.
2. It can not reference or update the table test.
3. To restart the database, execute pg_ctl restart.
4. You can reference or update table test.

1. Since initdb needs to be run as an administrator user, run it as root user.
2. The directory of the database cluster specifies either a new directory or an existing empty directory.
3. If existing files exist in the database cluster directory, they are deleted.
4. Specify the directory of the database cluster using the command line argument of initdb or the environment variable PGDATA.
5. The character set specified by initdb is common to all databases in the cluster.

1. Tables can be added to the template database template0  like a normal (non template) database. 
2. Tables can be added to the template database template1 like a normal (non template) database. 

3. When you create a new database with CREATE DATABASE, unless specified in the option, template0 is used as a template database. 

4. To create a new template database called template2, add the TEMPLATE option when executing the CREATE DATABASE command.

5.  By default, no users can connect to the template database template0.

1. used for high availability, it is a mechanism to duplicate databases across multiple servers.
2. Immediately after installation, three databases, template0, template1, and postgres, are provided.

3. Only one database cluster can be created on one server.

4. Different versions of PostgreSQL server can be used for each database in the database cluster.