Db2 directory

The Db2 directory contains information that Db2 uses during normal operation.

You can use SQL to retrieve data only from the directory tables that are listed in Db2 directory tables. You can submit queries against the Db2 catalog for Db2 directory objects.

The directory consists of a set of Db2 tables that are stored in table spaces in system database DSNDB01. Each of the table spaces that are listed in the following table is contained in a VSAM linear data set.

Table 1. Directory table spaces
Table space name Description
SCT02

Contains the internal form of SQL statements that are contained in an application. If you bound a plan with SQL statements in a prior release, Db2 created a structure in SCT02.
SPT01
Skeleton package
 Contains the internal form of SQL statements that are contained in a package.
SYSSPUXA Contains the contents of a package selection.
SYSSPUXB Contains the contents of a package explain block.
SYSLGRNX
Log range
 Tracks the opening and closing of table spaces, indexes, or partitions. By tracking this information and associating it with relative byte addresses (RBAs) as contained in the Db2 log, Db2 can reduce recovery time by reducing the amount of log that must be scanned for a particular table space, index, or partition.
SYSUTILX
System utilities
 Contains a row for every utility job that is running. The row persists until the utility is finished. If the utility terminates without completing, Db2 uses the information in the row when you restart the utility.
DBD01
Database descriptor (DBD)

Contains internal information, called database descriptors (DBDs), about the databases that exist within the Db2 subsystem.

Each database has exactly one corresponding DBD that describes the database, table spaces, tables, table check constraints, indexes, and referential relationships. A DBD also contains other information about accessing tables in the database. Db2 creates and updates DBDs whenever their corresponding databases are created or updated.
SYSDBDXA Contains the contents of a DBD section.
Tip: For best results, check the consistency of the Db2 catalog and directory regularly, even outside of the migration process. For detailed instructions, see Verify the integrity of Db2 table spaces and Check for consistency between catalog tables.