Why need the database maintenance?
PostgreSQL, like any database requires regular maintenance tasks.
You can prevent from slow response or expanding database size by executing the maintenance tasks.
Execution Examples
To maintain the database, use PostgreSQL's maintenance commands.
Please refer the execution example below. Use su command to switch to user "postgres".
Example 1
% vacuumdb -v -z -d dnpwmldb -U postgres
This command recovers or reuses disk space occupied by deleted data.
* When you execute the vacuumdb command, it may cause poor performance for Denbun.
Example 2
% vacuumdb -f -v -z -d dnpwmldb -U postgres
% reindexdb -d dnpwmldb -U postgres
This command recovers or reuses disk space occupied by deleted data.
* It compacts the data and saves it again. It makes more disk space.
* It recreate the index to delete the unnecessary indexes.
* All the users cannot use Denbun when you perform vacuumdb (with -f option), or reindexdb command.
* The process time varies depending on the data volume.
Please try [Example 2] if you feel poor performance for Denbun.
We recommend that you perform [Example 1] weekly and perform [Example 2] monthly basis.
The process speed varies depending on maintenance frequency.
About Message Indexes Maintenance Tasks
Denbun POP version saves search and status data in message indexes files.
It is important to run "Optimize Message Indexes" to keep good performance.
The "Optimize Message Indexes" can be performed from the menu after the login.
The "Optimize Message Indexes" can be performed for all the users in a lump in the administration tools.
Please refer the following pages fro each function.
In "Optimize Message Indexes" function, the following processes are performed for message indexes for each user.
This command recovers or reuses disk space occupied by deleted data.
* It compacts the data and saves it again. It makes more disk space.
* It recreate the index to delete the unnecessary indexes.
If response of Denbun becomes slow, please try to perform "Optimize Message Indexes".
Please perform "Optimize Message Indexes" regularly, e.g. once a week or month.
The process speed varies depending on maintenance frequency.
* When you execute the vacuumdb command, it may cause poor performance for Denbun.
* Users cannot use Denbun when you perform "Optimize Message Indexes" for the users.
* The optimization takes some time according to the amount of message data.
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