Compaq COBOL
DBMS Database Programming Manual


Previous Contents Index

8.7.2 PERSONNEL-UPDATE Sample Run---Listing After Promotion

This sample report (Example 8-8, created by PERSONNEL-UPDATE in Section 8.7, corresponds to the data in Figure 5-26.

Example 8-8 Sample Run of PERSONNEL-UPDATE After Promotion

                  EMPLOYEE LISTING 
 
            MANAGER OF GROUP A IS: HOWELL 
GROUP B3 
SUPERVISOR IS: KLEIN 
 
GROUP B3 EMPLOYEES   EMPLOYEE NUMBER    EMPLOYEE NAME 
                         07000           NEILS 
                         01400           RILEY 
GROUP B2 
SUPERVISOR IS: MOORE 
GROUP B2 EMPLOYEES   EMPLOYEE NUMBER    EMPLOYEE NAME 
                         05500           BAKER 
                         02000           DEANE 
                         07400           FIFER 
GROUP B1 
SUPERVISOR IS: NOYCE 
 
GROUP B1 EMPLOYEES   EMPLOYEE NUMBER    EMPLOYEE NAME 
                         04000           BURLEW 
                         01000           RAVAN 


Appendix A
COBOL Database Programming Reserved Words

The italicized words in this list are relevant to (both) database programs and other programs.

ALL
ALSO
ANY

BATCH

COMMIT
CONCURRENT
CONNECT
CONTAIN
CONTAINS
CURRENCY
CURRENT

DB
DB-ACCESS-CONTROL-KEY
DB-CONDITION
DB-CURRENT-RECORD-ID
DB-CURRENT-RECORD-NAME
DB-EXCEPTION
DBKEY
DB-KEY
DB-RECORD-NAME
DB-SET-NAME
DB-STATUS
DB-UWA
DISCONNECT
DUPLICATE
DUPLICATES

EMPTY
END-COMMIT
END-CONNECT
END-DISCONNECT
END-FETCH
END-FIND
END-FREE
END-GET
END-KEEP
END-MODIFY
END-READY
END-RECONNECT
END-ROLLBACK
END-STORE
ERROR
EXCLUSIVE

FETCH
FIND
FIRST
FREE

GET

KEEP

LAST
LD
LIMIT
LIMITS

MATCH
MATCHES
MEMBER
MEMBERSHIP
MODIFY

NEXT
NULL

OFFSET
OTHER
OTHERS
OWNER

PRIOR
PROTECTED

READY
REALM
REALMS
RECONNECT
RECORD
RELATIVE
RETAINING
ROLLBACK

SET
SETS
STORE
SUB-SCHEMA

TENANT

UPDATE
UPDATERS
USING

WAIT
WHERE
WITHIN


Glossary


access mode: In a database environment, that part of the COBOL data manipulation language READY statement's usage mode that describes what capabilities your run unit will have with regard to records in the realm you have readied. The access mode can be RETRIEVAL (read only) or UPDATE (read and write). See also usage mode and allow mode.

allow mode: That part of the DML READY statement's usage mode that describes what you will allow other run units to do while your run unit works with storage areas in the realms you have readied. The allow mode can be CONCURRENT, PROTECTED, EXCLUSIVE, or BATCH. See also usage mode and access mode.

at end condition: A condition caused during FETCH or FIND statement execution for a database, when no next logical record exists.

AUTOMATIC member: A database record that automatically becomes a member of a given set when the record is stored in the database. AUTOMATIC set membership is declared in the schema.

available mode: The state of a database record that allows its use by the Database Control System (DBCS) in executing an operation requested by a given run unit. A record is available if it is stored in a database area accessible to the DBCS, and the intended use does not conflict with the processing requirements of concurrent run units.

Bachman diagram: A graphic representation of the set relationships between owner and member record types used to analyze and document a database design.

BATCH RETRIEVAL usage mode: The state of a realm which allows concurrent run units to update the realm while the current run unit accesses a copy of the realm which was made at the point when the READY was executed.

BATCH UPDATE usage mode: The state of a realm in which the current run unit may access or update any data in the realm while allowing concurrent run units to retrieve from the realm but preventing them from updating the realm. Effectively similar to PROTECTED UPDATE.

Oracle CDD/Repository: The central repository of information about data elements, data structures, and relationships between data structures. Oracle CDD/Repository is used by Oracle CODASYL DBMS, Datatrieve, and Compaq COBOL. It does not contain actual data files. Rather, it contains definitions of schemas, storage schemas, and subschemas. Oracle CDD/Repository is available under a separate license.

CODASYL: An acronym for the COnference on DAta SYstems Languages, the committee that produced the document titled CODASYL COBOL Journal of Development. This document serves as the basis for the standardization of the Oracle CODASYL DBMS data manipulation language (DML).

CONCURRENT usage mode: The state of a realm in which it may be accessed by concurrent run units.

concurrency: The simultaneous use of a database or a sequential, relative, or indexed file by more than one user.

currency indicators: Pointers maintained by the Database Control System (DBCS) that serve as place markers in the database for your run unit.

data definition languages (DDL): The languages used to describe schemas, subschemas, and storage schemas. See also schema DDL, storage schema DDL, and subschema DDL.

data manipulation language (DML): The Oracle CODASYL DBMS language interface that permits programs to interact with Oracle CODASYL DBMS databases.

data-name: A user-defined word that names a data item described in a data description entry. In general formats, data-name represents a word that must not be reference-modified, subscripted, indexed, or qualified unless specifically allowed by rules of the format.

database: A collection of related records on a mass storage device. All of the records and sets are controlled by a specific schema.

database administrator (DBA): The person or group of people responsible for planning, designing, implementing, and maintaining a database.

database aggregate: A subschema group item or table defining one or more database items. A database aggregate can contain one or more database aggregates.

Database Control System (DBCS): The component of Oracle CODASYL DBMS that, together with the OpenVMS operating systems, provides run-time control of database processing.

database exception condition: The state that exists for a run unit when the DBCS detects a situation for that run unit that requires special handling.

database item: An elementary data item defined in a subschema. It corresponds uniquely to a data item in the subschema's host schema.

database key (dbkey): A numeric value that uniquely identifies a record in the database. The Database Control System assigns the value when a record is stored in the database. Although your run unit cannot directly access database keys, they are used by the Database Control System whenever you store, retrieve, or manipulate a record. Dbkey values are notated in the form x:y:z, where x is the area, y is the page, and z is the record number.

database key condition: A condition for which a truth value can be determined, that: (1) two specified database key values identify the same database record, (2) a database key value is null, (3) or a key value is identical to any database key value in a keeplist.

database key identifier: A phrase in a COBOL source program that refers to a database key value within a currency indicator or a keeplist.

database management system (Oracle CODASYL DBMS): A system for creating, maintaining, and accessing a collection of interrelated database records that may be processed by one or more applications without regard to physical storage. Oracle CODASYL DBMS establishes logical relationships among records. Data is described independently of application programs, providing ease in application development, data security, and data visibility. Oracle CODASYL DBMS is available under a separate license.

database object: A set type, record type, realm, record key, or data item defined in the schema.

database page: The unit of data transfer between Oracle CODASYL DBMS and the OpenVMS operating systems. Each database page consists of one or more blocks of 512 bytes each.

Database Query utility (DBQ): An online interactive utility that allows the user to access a Oracle CODASYL DBMS database directly and that shows the results of each execution of a DML statement. This utility provides low-level query facilities for data processors.

DB-CONDITION: A database special register whose value indicates either a successful condition or an exception condition.

DB-CURRENT-RECORD-ID: A database special register containing the subschema user ID number (UID) of the record type of the current record of the run unit. It contains zero if there is no current record of the run unit.

DB-CURRENT-RECORD-NAME: A database special register containing the name of the record type of the current record of the run unit. It contains spaces if there is no current record of the run unit.

DBA: See database administrator.

DBCS: See Database Control System.

dbkey: See database key.

DB-KEY: A database special register that holds the dbkey of the record accessed by the last FETCH, STORE, or FIND statement. This special register can be used to fine tune storage strategies in the database.

DBMS: See database management system.

DBQ: See Database Query Utility.

DB-UWA: A database special register which serves as the record delivery area that the Database Control System (DBCS) uses to make data items available to your program.

DDL: See data definition languages.

de-edit: The logical removal of all editing characters from a numeric edited data item in order to determine that item's unedited numeric value.

deadlock: A database processing situation in which two or more run units are stopped by conflicting requests for locked records.

DML: See data manipulation language.

DMU: See Dictionary Management Utility.

empty set: A database set occurrence containing no member records.

EXCLUSIVE usage mode: The state of a realm in which it cannot be accessed by a concurrent run unit.

FIXED member: A record, upon becoming a member of a set occurrence of a FIXED set type, that must remain a member of that set until it is erased from the database. Fixed set membership is declared in the schema DDL. Compare with MANDATORY member.

INSERTION class: An attribute of member records that describes how and when members are added to database sets. See also AUTOMATIC member and MANUAL member.

journal file: A database file that contains all records modified by a run unit, usually chronologically ordered. A journal file allows reconstruction of the data to prefailure conditions in case of database contamination due to system or program failures.

journaling: The act of creating, writing, or both, to a journal file.

junction record: A record inserted between two records of the same type. You can use a junction record to simulate what would otherwise be an illegal set relationship for Oracle CODASYL DBMS, that is, a record type being a member of a set that it owns. Also, using a junction record helps avoid data redundancy and inconsistency.

keeplist: A list of database keys used by a run unit to lock records for later reference.

locking: The Compaq COBOL facilities that allow concurrent use of a database or a sequential, relative, or indexed file without corrupting their records. RMS on OpenVMS VAX maintains locks on a file, whereas RMS on OpenVMS Alpha maintains locks on a file, individual records, or both. In Oracle CODASYL DBMS, locks are maintained on individual records, entire realms, or both.

MANDATORY member: A record, upon becoming a member of a set occurrence of a set type, must remain a member of that or some other set occurrence of that set type until it is erased from the database. MANDATORY set membership is declared in the schema. Compare with FIXED member.

MANUAL member: A database record that becomes a member of a given set by explicit direction of the application program using the CONNECT statement. MANUAL set membership is declared in the schema.

member condition: The condition, for which a truth value can be determined, that a database record is a member of one or more sets.

member record: A database record, other than the owner record, included in the set. There may be one or more member record types in a set. There may be zero or more member records in a set.

nonsingular set: A database set not owned by the SYSTEM. See also SYSTEM-owned set and owner record.

null: A data attribute associated with currency indicators and database key values. This attribute is independent of the value of the contents of data items.

OPTIONAL member: A database record that does not necessarily remain a permanent member of a set. Its membership in a set may be changed using the DISCONNECT statement without its being deleted from the database. OPTIONAL set membership is declared in the schema.

owner record: The head of a group of database records that make up a set. There can be only one record type as the owner for each set type and one owner record occurrence for each set occurrence.

PROTECTED usage mode: The state of a realm in which it may be retrieved from but cannot be modified by concurrent run units.

quiet point: A time when no run units are accessing a database. Quiet points and transactions are mutually exclusive (for the entire database). Compare with transaction.

For the run unit, the time between a COMMIT or ROLLBACK, and the following READY.

ready mode: The state of a realm after execution of a READY statement for that realm and before the execution of a COMMIT or ROLLBACK statement for that realm.

realm: One or more schema areas. Realms are declared in the subschema. See also area.

realm currency indicator: A currency indicator (in other words, database key value) associated with a particular realm. A realm currency indicator identifies a particular database record, position in the realm, or both.

record key: A key whose contents identify a record in an indexed file or within a record type in a database. Within an indexed file, record key is either the prime record key or an alternate record key. Within a database, a record key may or may not have ordering significance.

record occurrence: A user-stored instance of a record type. A record occurrence is the actual physical data representation of a single record in the database, but not its definition, which is the record type.

record order key: A record key associated with a record type in a database. The definition of a record order key in the schema causes the DBCS to maintain the records in the specified logical sequence based on values of the record order key.

record selection expression: A word or group of contiguous words in a COBOL source program that specifies the algorithm to be used by the Database Control System (DBCS) to identify a specific database record.

record type currency indicator: A currency indicator associated with a particular database record type. A record type currency indicator identifies a particular record of the record type. If the subschema includes a record order key for a record type, its associated currency indicator identifies a particular record, position in the record type, or both.

RETRIEVAL usage mode: The state of a realm in which the current run-unit may only retrieve from it.

schema: The logical description of a database, including data definitions and data relationships. The schema is written using the schema data definition language (schema DDL).

schema DDL: The language used to define the logical structure of a database.

schema-name: A user-defined word that identifies a schema.

section header: A combination of words (followed by a separator period) that indicates the beginning of a section in the Environment, Data, and Procedure Divisions of a COBOL program. In the Environment and Data Divisions, a section header consists of reserved words followed by a separator period in the Division. SUB-SCHEMA SECTION is a valid section header.

set: A defined relationship among records in a database. A set contains an owner record and zero or more member records. See also set occurrence , set type, and empty set.

set member: A record stored in the database as a nonowner participant in a specific set.

set-name: A user-defined word that identifies a set type.

set occurrence: An instance of a database set type. A set occurrence is the actual data in the set, not its definition, which is the set type.

set-ordering criteria: The specification for the positioning of a member record in a set by the DBCS. The schema defines this specification.

set owner: A database record occurrence whose existence establishes the existence of a specific set occurrence.

set type: A specific named set that has been defined in the schema data definition language. It is the definition of a collection of sets that have identical characteristics. Set types are declared by the schema data definition language.

set type currency indicator: A currency indicator associated with a particular database set type. A set type currency indicator identifies a particular set of the set type and a particular record, position in that set, or both.

simple condition: Any single condition from the following list:

relation condition
class condition
condition-name condition
switch-status condition
sign condition
success/failure condition
simple-condition (in parentheses)
tenancy condition (Oracle CODASYL DBMS simple condition type)
empty condition (Oracle CODASYL DBMS simple condition type)
database key condition (Oracle CODASYL DBMS simple condition type)

singular set: See SYSTEM-owned set.

storage schema: A description of the physical storage of data in database files. The storage schema is written using the storage schema data definition language.

storage schema DDL: The language used to define the physical organization of the database.

SUB-SCHEMA SECTION: The section of the Data Division that defines the subschema and keeplists to be used by the COBOL program.

subschema: A user view of a database. The subschema can include everything in the original schema DDL or any part thereof. The subschema is written using the subschema data definition language (subschema DDL).

subschema DDL: The language used to define the user view of a database.

subschema entry: An entry in the Subschema Section of the Data Division that specifies the subschema to be accessed by the COBOL program.

subschema-name: A user-defined word or nonnumeric literal that identifies a subschema.

SYSTEM-owned set: A set owned by the SYSTEM rather than by a record type. SYSTEM-owned sets have only one occurrence in the database and are used for relationships with large numbers of member occurrences or as entry points into the database.

tenancy condition: The condition, for which a truth value can be determined, that a record is a member, owner, or either, of one or more sets.

tenant: A database record that is either the owner or a member of a specific set.

tenant record: An owner or member record of a set.

UPDATE usage mode: The state of a realm in which the current run-unit may update it, as well as retrieve from it.

usage mode: The combination of the DML READY statement's allow mode and the access mode. The usage mode describes how a READY realm can be accessed. The eight usage mode combinations are:

CONCURRENT RETRIEVAL
CONCURRENT UPDATE

EXCLUSIVE RETRIEVAL
EXCLUSIVE UPDATE

PROTECTED RETRIEVAL
PROTECTED UPDATE

BATCH RETRIEVAL
BATCH UPDATE

PROTECTED and RETRIEVAL are the default.

See also access mode and allow mode.

user work area (UWA): A portion of memory assigned to the program's run unit at run time. The run unit delivers data for the DBCS to this area, and it is here the DBCS places data requested from the database for retrieval by the run unit.


Index Contents