Configuring the Volatile Attribute for Named Tables

Volatility is an indication to Spectrum Spatial that information from a data source can change at any time. The default value for TAB, and JDBC-based (Oracle, SQL Server and PostGIS) named tables is set to true, meaning that for each data access operation, such as a query or insert, Spectrum Spatial checks with the data source to find out if the table is volatile and if so, whether the data changed. If the data has changed, the cache is flushed and the table is reloaded before the data access operation can proceed. If the table did not change, the query or other operation is carried out on the data in the cache. See Supported Data Sources in the Spectrum Spatial Guide for more information about what triggers a change for each data source.

Volatility is by default disabled (set to false) for named tables that are uploaded from MapInfo Pro using Map Uploader. Volatility is enabled by default for any named tables created with Spectrum Spatial Manager. An administrator with a Spectrum admin, spatial-admin, or spatial-sub-admin role can change this by selecting the Volatile checkbox in the table matching section of the Map Uploader, or on the Spectrum Spatial Manager Create Table page before saving the new table. If multiple tables are created, their volatility is enabled (set to true). An admin can change this for any table on the Table Settings page once a named table is created.

For more information on creating and modifying named tables in Spectrum Spatial Manager, see the Managing Spatial section of the Spectrum Spatial Guide.

Disabling Volatility

Disabling volatility should be done only on tables that do not change. For example, when generating tiles from volatile TAB files, the operation will perform very slowly. If you are using PostGIS, you may also want to consider disabling volatility to avoid encountering connection errors in Spectrum Spatial Manager (for example, when viewing the sample rows on the table details page).

Volatility can be disabled on the table details page in Spectrum Spatial Manager.

  1. On the Data menu, select Repository.
  2. On the navigation panel, select NamedTables, and then select a table from the list.
  3. On the Resource Info tab are table details including the Volitile setting for the table. Click Modify to change the Volitile setting.

You must restart Spectrum Spatial in Spectrum Spatial Manager when the named table is set as non-volatile.

Note: Do not use the updateNamedResource operation in the Named Resource Service to change this value or manually edit the named table definition that you accessed via WebDAV in a text editor.