Administration Guide : Xinet Statistics and Database Operations — the Database, Admin subtab : Database administration settings

Database administration settings
Clicking on the Database > Admin > Settings tab presents the interface which allows you to start and stop the database and to fine tune settings to enhance performance.
Stopping and restarting the database
You can stop the database (MySQL) safely without adversely affecting the Xinet software using the dblogd(8) daemon. Xinet will stop logging activities on your file system during the period while it is shut down. Then, upon restarting, the database daemon will check for changes and bring the database up-to-date.
Database Daemon (dblogd(8))
Xinet, via the dblogd(8) daemon, will stop writing data to MySQL when the file system that contains the database itself is in danger of becoming full. Serious errors that announce this danger will appear in the log file, which you can view under the Logging, Database tab. However, Xinet will continue run but no changes or updates are recorded. The act of logging information to MySQL will simply be suspended and will resume as soon as the problem has been corrected. In such instances, you will see Status: Stopped at the top of the Settings GUI. You may also provide an Email Address if you would like someone notified about the situation. Once sufficient space has been allocated to the file system, the dblogd(8) daemon will write any changes into the database.
You can set the danger size for suspension of database activity.
To set the size of reserved disk space and set up email notification:
In the Free Source Minimum field, type in a value.
Click Update to register the change.
Add an appropriate Email Address and click the associated Update button.
This will allow the system to send email whenever a Quick Sync, Full Backup, Quick Backup or a Table Check fails. Schedules describes each of these events.
You may also start and stop the dblogd(8) daemon with the Stop Daemon and Restart Daemon buttons. The Stop Daemon button is useful for suspending updates of the database during repairs and maintenance. Should you notice a crashed or hung dblogd(8) process, the Restart Daemon button allows you to restart it without having to restart MySQL.
About Directories
You may see additional directories listed, depending on the Xinet products licensed for your system. All installations should see:
This indicates the directory where Xinet and MySQL were installed. On Unix systems, this will be /usr/etc/venture. On Windows systems, it varies, depending where you installed the software. The default location is C:\Program Files\Xinet\Venture.
This indicates the directory where the tables containing data for Xinet gets written. The default directory for Unix installations will be /usr/etc/venture/data/webnative and on Windows systems C:\Program Files\Xinet\Venture\Data\WebNative. Most administrators will want to change this directory to one with more adequate storage space, using the Edit button to the right.
If you move them, each subdirectory of the default Data subdirectory needs to have its own, discrete location. In other words, they can not share the exact same location in the file system. Depending on the Xinet products for which your sever has been licensed, you may have more than the two Data subdirectories shown here.
This indicates where data for FullText indices will be written. The default directory for Unix installations will be /usr/etc/venture/data/wnvfti and on Windows systems C:\Program Files\Xinet\Venture\Data\WNVfti.
The database will use the directory shown here to write intermediate results of its activities. By default, this will be /tmp/ on Unix systems and on Windows systems, the default temp directory, e.g., C:\winnt\temp. You may change this directly, using the Edit button at the right.
Changing the stored data and temporary files directories
Xinet provides a convenient way for you to change the locations where it stores data and temporary files. When you change these locations, all of the tables containing your old data will be preserved and moved to the new locations.
To change the location of these directories:
Click Database > Admin > Settings.
Click Edit for the Data Directory or the Temp Directory.
Use the pop-up list iteratively to select a new directory. The (New Folder) option allows you to type in a new directory name.
If you type in a new name, use the Create Folder button to submit it.
Click Set Directory.
Click Close.
Memory and Thread Limits
Memory Buffer Size
This refers to the amount of RAM to be used by the mysqld daemon when processing events. The amount of available RAM for a server will determine the best value for this field. If a machine is to be used primarily by remote Xinet users, and production activities are not already taxing the machine, then you can set this value to up to 25% of the total available RAM. For example, if a server has 2 GB RAM, the value in this box can be up to 500 MB. If a machine is used for both production and Xinet operations, 10% of the total available amount may be a better choice—a value of 200 MB would be set in that field.

It is important to note that this value is most important during heavy periods of memory usage, such as during the creation of a FullText index.

When you change the Memory Buffer Size setting, click the Update button to register the change.
Query Cache
The query cache allows the database to store a set of search criteria along with the returned results. Later, should another user initiate the same search, the server uses the results in the cache rather than reprocessing the search criteria and executing the search another time. Queries must be exactly alike (byte by byte) before they are considered identical, and the user must also have appropriate privileges to see the data involved before the cache will be used. Using a query cache is most useful if your database tables don’t change very often and the server receives many identical queries. Each time tables change, the database flushes relevant caches to ensure that Xinet will never deliver old data.
Setting the Query Cache Size or the Query Cache Limit to 0 disables query cache storage. Setting them to non-zero numbers brings the cache into use. You’ll have to experiment to figure out whether query caching is right for your system.
The Query Cache Size
There is a minor performance hit associated with the maintenance of the cache itself, which can start to be significant if Query Cache Size is set too large. Xinet recommends that you keep its size below 128 Mbytes. Try 64 Mbytes first, provided you have sufficient RAM to spare. Then, assess whether that is right by examining Free Memory value in the Query Cache Info portion of the Stats page. You don’t want to fill up more than 80% of your cache within a given 24-hour period.
Also check the Hit Rate on the Stats page. If yours is below 50%, you should probably turn off the feature.
The Query Cache Limit controls the maximum size of individual query results that can be cached. Xinet recommends that you do not exceed 2 Mbytes.
Access Control List
If you are accessing the database from another server using Open Database Connectivity (ODBC) or another instance of MySQL, use the Access Control List pop-up menu to select the ACL which provides that server access to the Xinet server. The choices which appear in the pop-up menu include any IP-based ACLs which you previously established on the Xinet server. (About Access Control Lists provides more information about ACLs.) An ACL does not need to be applied for Xinet users to see Xinet, search metadata, etc., as from MySQL’s perspective, all are local MySQL users.
Metadata Inheritance
The Enable Metadata Inheritance option, when enabled, will cause any file newly-introduced to the file system which has the same name and location as a previously-deleted file to inherit the original file’s metadata. This option is useful for automating some workflows, but, it’s not appropriate for all sites.
If the new file contains XMP metadata of its own, that metadata will be retained and replace any already stored in the database for those fields.
Note: By default, the file size of the asset file has to be zero for the Enable Metadata Inheritance option to work correctly. To change that behavior so that inheritance happens for any overwritten file, add the line FullPlaceHolders=1 to the “Options” section of the dblogd.conf.
Custom Namespaces
If you add custom namespaces on your server, information about them, including their URIs, will appear on the Settings page. Adding Custom XMP namespaces provides details about custom namespaces.