Database Operations

This section describes functions that can be used after you put virtual database servers into operation.

Changing Database Settings

The settings specified when virtual database servers are created can be changed later. As shown in the following table, you may need to restart the virtual database servers in order to apply the changed settings.

Table 1. Settings That Can Be Changed
Settings Description Restarting of Virtual Database Servers
Database engine version Changes the version of the database engine Necessary
Virtual database server type Changes the virtual database server type Necessary
Database capacity expansion, or changing of disk type Increases the data block storage capacity, or changes the disk type Necessary
Redundancy settings Changes the redundancy settings of virtual database servers Not necessary
Security group settings Changes the security group information that is set on virtual database servers Not necessary
Automatic backup time Changes the time when automatic backup is performed Not necessary
Backup retention period Changes the backup retention period Not necessary
Automatic maintenance Changes whether or not to perform automatic maintenance Not necessary
Automatic maintenance time Changes the time when automatic maintenance is performed

Not necessary

Note: Restarting is not necessary when you change the setting, but restarting is carried out when you perform maintenance.
Automatic minor version upgrade Changes whether or not to perform a minor version upgrade of the database engine automatically

Not necessary

Note: Restarting is not necessary when you change the setting, but restarting is carried out when you upgrade.

Starting/Terminating/Restarting a Virtual Database Server

You can start up, terminate, or restart a virtual database server. When you restart a virtual database server, the operation varies depending on whether the redundancy settings are "Enable" or "Disable."

  • When the redundancy settings are "Enable"

    Failover takes place, then restarting is carried out.

  • When the redundancy settings are "Disable"

    Normal restarting is carried out. (The server stops for approximately 10 minutes.)

Applying Patches to Database Virtual Servers

When patches are database engine patches or security updates are released, it is possible to apply patches. It is necessary to reboot database virtual servers in order to apply patches. For the parameters, etc. when rebooting, refer to "Restart virtual database server" in the "API Reference - Application Platform Service".

Deleting a Virtual Database Server

Take one of the following actions and then delete the virtual database server:

  • Create a DB snapshot before deletion

    Tip: If you create a DB snapshot before you delete a database server, you can create a new database server by restoring the DB snapshot that contains the database server in the condition it was before it was deleted.
  • Delete immediately

Settings for Monitoring

You can monitor the resources on virtual database servers. You can monitor resources at the OS level, and monitor resources within the database engine.

You can set threshold values for each item, and set an action that will be taken (send e-mail) when the threshold value is exceeded.

Table 2. Settings for Monitoring
Item Description
Check interval 10 minutes
Display period Refresh 1 hour, 3 hours, 6 hours, 9 hours, 12 hours, 1 day (by default), 3 days, 1 week
Custom Any part of last week, from one to seven days
Items to monitor
  • CPU usage
  • Number of DB connections
  • Free disk space
  • Free memory space
  • Average number of disk I/O operations (number of times read and write are executed) per sec.
  • Number of requests in disk IO queue (read and write requests)
  • Delay time behind the read replica master
  • Binary log size
  • Average value of number of bytes that are read from disk or written to disk per sec.
  • Average length of time that was spent per disk I/O (read and write) operation
  • Amount of swap space in use

Monitoring of Logs

You can refer to PostgreSQL engine logs.

Note: Log files are rotated every day. 72 hours of data is retained.

Creating a Read Replica

You can create a read replica in order to distribute the load for database references.

Important: A read replica differs from redundancy settings in that the data is duplicated asynchronously from the source database. Therefore, you may view old data as a result of an SQL statement for reference.

DB Snapshot Management

You can create a DB snapshot of a virtual database server at a specific point in time, and create a new virtual database server by using the DB snapshot. Following functions related to DB snapshots are provided:

  • Creation of a DB snapshot
  • List display of a DB snapshot
  • Information display of a DB snapshot
  • Duplication of a DB snapshot
  • Deletion of a DB snapshot

Event Notification Settings

You can configure settings so that you receive notifications (via email) regarding events that take place on a virtual database server.

Table 3. List of Events
Source Type Event Types Description
db-instance availability Starting/termination/restarting of a database virtual server (includes restarting due to the failover option)
backup Creation of a DB snapshot, Starting or stopping of an automatic backup
configuration change Modification of a database virtual server
creation Creating a virtual database server
deletion Deleting a virtual database server
failover Start and completion of failover
failure When the status of a parameter value of a DB parameter group is abnormal
low storage When over 80% of the allocated storage is being used
maintenance When performing security updates or minor version updates of database virtual servers
recovery Restoration of virtual database servers
restoration When restoring a database virtual server from a point-in-time or a DB snapshot
read replica Reading of a replica
db-snapshot creation Creation of a DB snapshot, Creation of an automatic backup
deletion Deletion of a DB snapshot
notification Duplication of a DB snapshot
restoration Restoration of a database virtual server from a DB snapshot

Transparent Data Encryption

Using the transparent data encryption function makes it possible to encrypt the data stored in databases. For details, refer to the Database Service User Guide.