DBD segment type format

The IMS catalog DBD segment type contains metadata about an IMS user database.

This information is collected from the parameters submitted to the DBDGEN utility during system definition.
Segment name
DBD
Parent name
HEADER
Sequence field
DBDSEQ
Segment length
552 bytes
Table 1. DBD segment type format
Offset (bytes) Length (bytes) Data type Field name Description Unique key field
1 2 X LEN Length of this segment  
3 2 X CTL Control field  
5 2 X SEQNUM Sequence number  
9   17 X DBDSEQ Sequence field, type = U X
  9 4 X CATVERS Version number of the database definition that is recorded by this DBD segment and its dependents.  
  13 13 C TSVERS ACB generation timestamp for this version, in the following format: yyDDDHHmmssff  
26 1 C FILLER Reserved  
27 2 X RLVL ACB generation utility release level  
29 7 C ACCESS DL/I database type for this database  
36 4 C OSACC Access method for this database  
40 6 C PROT In a secondary index database, this field indicates if integrity protection is used for index pointer segments.
  • If this field contains PROT, a delete operation that removes an index pointer segment also removes the target segment pointer but the source segment is not deleted.
  • If this field contains NOPROT, an application program can replace all fields within a pointer segment except the constant, search, and subsequence control fields.
 
46 7 C DOSCOMP Indicates that this database is a DLI/DOS index and that a DLI/DOS segment code is included in the prefix of segments in this database. IMS preserves the code during segment processing and provides a new code when segments are inserted.  
53 8 C PSNAME The name of the HALDB Partition Selection exit routine for this database.  
61 8 C RMNAME The module name of the randomizing exit routine for an HDAM or PHDAM database, or a Fast Path data entry database (DEDB).  
69 4 X RMRBN The maximum relative block number that the randomizing exit routine produces for this HDAM or PHDAM database. This value is also the number of control blocks or intervals in the root addressable area of the database.  
73 4 X RMBYTES The maximum number of bytes of user data that can be stored in the root addressable area of this database by an unbroken sequence of insert operations. A database record that exceeds this size is partially stored in the overflow area.  
77 2 X RMANCH The meaning of this field is different for Fast Path DEDB databases and full-function HDAM or PHDAM databases.

For DEDB databases, indicates the type of randomizer: a value of 1 indicates a one-stage randomizer. A value of 2 indicates a two-stage randomizer.

For HDAM and PHDAM databases, this value indicates the number of root anchor points in each control block or interval in the root addressable area of the HDAM or PHDAM database.

  
79 1 C RMXCI Indicates if this DEDB uses the Extended Call Interface (XCI) when it calls the randomizing exit routine.  
80 3 C FILLER01 Reserved  
83 1 C PASSWD Indicates if this database uses a default VSAM password (the DBD name) to prevent accidental database operations by programs other than IMS.  
84 1 C DATXEXIT Indicates if this database uses the Data Conversion user exit routine DFSDBUX1.  
85 1 C FPI Indicates if this database is a secondary index for a Fast Path database.  
86 255 C VERSION User-supplied version information for this database  
341 2 C FILLER02 Reserved  
343 2 X IDXCNT Number of shared secondary indexes  
345 8 C IDXNM01 Shared secondary index name  
353 8 C IDXNM02 Shared secondary index name  
361 8 C IDXNM03 Shared secondary index name  
369 8 C IDXNM04 Shared secondary index name  
377 8 C IDXNM05 Shared secondary index name  
385 8 C IDXNM06 Shared secondary index name  
393 8 C IDXNM07 Shared secondary index name  
401 8 C IDXNM08 Shared secondary index name  
409 8 C IDXNM09 Shared secondary index name  
417 8 C IDXNM10 Shared secondary index name  
425 8 C IDXNM11 Shared secondary index name  
433 8 C IDXNM12 Shared secondary index name  
441 8 C IDXNM13 Shared secondary index name  
449 8 C IDXNM14 Shared secondary index name  
457 8 C IDXNM15 Shared secondary index name  
465 8 C IDXNM16 Shared secondary index name  
473 8 C CREATEBY Reserved  
481 25 C ENCODING Code page used to encode all character data in this database. Individual segment and field definitions can override this value.  
506 47 C FILLER03 Reserved