Table spaces

A table space is a set of volumes on disks that hold the data sets in which tables are stored. A table space can have one or more tables.

IBM® Security Directory Server uses four DB2® table spaces.

Table space 0: SYSCATSPACE

The SYSCATSPACE table space stores a description of the database and its structure and contents. The disk requirements for this table space do not change with the size of the directory server. The disk space requirements are covered by the default directory server disk requirements.

Table space 1: TEMPSPACE1

The TEMPSPACE1 table space holds temporary data for sorting and collating DB2 results. The disk requirements for this table space grow at run time if a complex search is run against the directory server. The disk space requirement for this table space grows with the usage utilities, such as the bulkload tool.

When the bulkload utility is run, the disk requirement for the table space is approximately 2 GB. The bulkload utility uses the maximum space when millions of entries are loaded into the directory server.

Table space 2: USERSPACE1

USERSPACE1 holds the portion of the database that contains the attribute tables and attribute table indexes of the directory server. These tables are used for optimizing searches on specific attributes.

Table space 3: LDAPSPACE

LDAPSPACE contains the portion of the database that contains the LDAP entry table and LDAP entry table indexes of the directory server. The LDAP entry table contains a few searchable attributes, such as distinguished name (DN), and a full, non-searchable definition of each LDAP entry.

The LDAP entry table returns the attributes for an LDAP search operation.

In IBM Security Directory Server, version 6.2 and later, Database Managed Space (DMS) is the default table space type and the file system cache is disabled. In IBM Security Directory Server, version 6.1 and earlier, the default table space type is system-managed space (SMS) and the file system cache is enabled. In the SMS type table space, data are cached in the DB2 buffer pools and in the file system cache.

In IBM Security Directory Server, version 6.2 and later, you can select the table space type to use for the directory server. The table space type can be SMS or DMS. When DMS table space is set for a directory server, it supports the use of raw devices and disables file system caching. Along with a file, a raw device can also be added to the containers in DB2, version 9.1 and later. DMS provides an alternative to adding multiple physical disks to the containers for LDAP table spaces (LDAPSPACE and USERSPACE1). To know more about table space, see IBM Security Directory Server Version 6.3.1 Administration Guide.

You can use the idsdbmaint tool to convert an SMS table space to a DMS table space; and a DMS table space to an SMS table space. The idsdbmaint command supports the table space conversion. You cannot use Configuration Tool (idsxcfg) for table space conversion, as the tool do not support table space conversion. The maintenance of the LDAPSPACE and USERSPACE1 table spaces are supported by the idsdbmaint tool.