Structure of the Tblspace Tblspace

Each dbspace contains a tblspace called the tblspace tblspace that describes all tblspaces in the dbspace. When the database server creates a tblspace, it places an entry in the tblspace tblspace that describes the characteristics of the newly created tblspace. You cannot drop or move a chunk containing a tblspace tblspace.

A dbspace can have a maximum number of 2**20 tblspaces.

The default size of the first and next extents depends on whether the dbspace is the root dbspace or not, as shown in the following table.

Table 1. Default sizes for each extent and type of dbspace
Type of dbspace	Default Size of First Extent	Default Size of Next Extents
Root	500 KB for a 2 kilobyte page system 1000 KB for a 4 kilobyte page system	100 KB for a 2 kilobyte page system 200 KB for a 4 kilobyte page system
Non-root	100 KB for a 2 kilobyte page system 200 KB for a 4 kilobyte page system	100 KB for a 2 kilobyte page system 200 KB for a 4 kilobyte page system

You can specify a non-default size for the first and next extents for a tblspace tblspace in the following ways:

For the root dbspace, set the TBLTBLFIRST and TBLTBLNEXT configuration parameters.
For non-root dbspaces, use the onspaces utility -ef and -en options when you create a dbspace.