Application Programming Basics Flashcards
Dataset
A unit of data storage or retrieval consisting of one or more data records
Where in standard computing environments, it is a directory, what is it in mainframe?
A catalog
What is a catalog?
A dataset with information about other datasets
What type of information does a catalog keep about datasets?
Type, location, size, and format
What is the “root”, or “base” catalog structure called?
The master catalog
What does the master catalog contain?
Entries for datasets and for subcatalogs
What else is a subcatalog referred to as?
User catalogs
How do places organize catalogs to improve performance, security, and manageability.?
They create user catalogs to reduce the number of entries in the master catalog
Using which application would you list a dataset?
ISPF
What utility would you use to list datasets?
DSLIST utility
How are dataset names organized?
Hierarchical qualifiers. ex. zfs.S01.DEV
How can RACF be used to enforce security on a dataset
At the hierarchical level, for example, all datasets beginning with ZFS
When allocating a dataset, how do you specify space?
In blocks, records, tracks, or cylinders
Blocked data sets
Contain multiple records of fixed or variable record size
Unblocked data sets
Contain blocks of single records
On what is DASD data stored?
Tracks
Tracks
A unit of space on a DASD
How are tracks described?
As the number of bytes that can be written by a single read-write head in one position over the surface of a disk.
What is the maximum number of bytes on a 3390 track if a single record is written?
56,664
Storage waste occurs if the size of the track ____
is not a multiple of the block size
What’s a more accurate way to measure the amount of storage used by a dataset?
The number of tracks whose size is consistent for a device type
What is the largets unit of allocation?
A cylinder, made up of several tracks.
Name that acronym
AM
Access Method
Name that acronym
BSAM
Basic Sequential Access Method
Name that acronym
QSAM
Queued sequential access method
VSAM
Virtual Storage Access method
BDAM
Dasic Direct access method
BPAM
Basic partitioned access method
What is the simplest of basic data storage types?
flat file
How is a flat-file accessed?
Flat files are usually QSAM but are occasionally BSAM data sets.
PDS
Partitioned data set
Partitioned data set
A data set that is divided into sections called members.
A PDS has a directory of its members that can contain addition information. What is this called?
Statistics
True or False
A Members of a PDS inherit the same format type?
True
What is the use case for PDS?
PDS are used to store and organize most of the source and executables required to run and manage applications on an enterprise system.
Is the following record a PDS or a member of a PDS?
IBMUSER.JCL(ARUNREP)
Member
Is the following record a PDS or a member of a PDS?
IBMUSER.JCL
PDS
When is a PDS referred to as libraries?
When they use a naming convention indicating the type of source or module that the PDS contains
How are libraries often organized?
Into production or application groupings
When organizing libraries into groupings, what type of grouping are often used?
site-specific naming conventions, such as PROD.APP.librarytype or DEVEL.APP.librarytype.
How is library security managed?
Through RACF or a similar security system
SCM
Software configuration management
How is access to the underlying PDS and migration of the PDS members between environments managed?
Using a Software configuration management (SCM)
VSAM
Virtual storage access method
Virtual storage access method
VSAM) refers to the access method software for direct processing by key or record number, or sequential processing of fixed and variable length records.
CLUSTER
Used for certain VSAM files such as the Keyed Sequential Data Set (KSDS)
Why do certain VSAMs get referred to as a cluster?
They consist of an index file and a data file. These two components constitute the cluster.
Whihc IPFS option displays datasets?
3.4
When accessing option 3.4 and the enter key is pressed, the system initially accesses the ______, which contains a record of all data sets on the system.
Master Catalog
Datasets are displayed including the space allocation, which is specified in _________
Block, tracks, or cylinders
A dataset format of FB is common and indicates that data within the dataset is ____________
Fixed and blocked
What are other VSAM file organizations?
Entry Sequenced Data Set (ESDS)
Relative Record Data Set (RRDS)
Linear Data Set (LDS)
Why is VSAM used by many applications and systems?
Compared to DBMS, it provides direct and indexed access with low overhead
What considerations should a system or application use when using a VSAM instead of a DBMS?
Issues such as record locking, logging, and recovery facilities
T/F
VSAM datasets are only used in database structures?
False
VTOC
Volume Table Of Contents
Volume Table Of Contents
VTOC is searched to find out where the data set resides on the disk.
When does the system search the VTOC?
After z/OS searches the catalog to find the volume where the dataset resides
What does a dataset name consist of?
A number of qualifiers
What is the maximum character limit of a qualifier?
8
Most organizations use which product to facilitate the migration of the source code between development, test and production environments, and to provide versioning, history, and audit trails?
Software Configuration Manager
True or False
A PDS is a type of VSAM data set.
False
A PDS is a partitioned data set, which is not a VSAM data set.
T/F
A Key Sequence Data Set (KSDS) is a type of VSAM data set.
True
T/F
VSAM data sets are only used in database structures.
False
VSAM datasets are the lower-level data stores for databases, but they can also be used, outside of a database management system (DBMS), for direct access by application programs.
T/F
A VSAM cluster consists of data files and indexes.
True
What does a database consist of to be considered a database?
A combination of a structured data store and a database management system (DBMS).
What is a database management system (DBMS)?
Software used to allow users and application programs to access and use databases.
When using a database to store and access data, what communicates with the DBMS to enable it to access and manipulate managed data?
The application
An enterprise quality database manages what?
Concurrency
Security
Recoverability
What is data concurrence?
The ability of multiple applications or threads to update or read the same data in a consistent manner
What is data security?
The control of access and operations to sets of data within the database
What is data recoverability?
Recoverability and the maintenance of logs, journals, and backups to enable the recovery of data to a previous point in time or to a previous state in the event of failure, error, or disaster
What are two of the more popular DBMS software?
IMS
Db2
IMS
Information Management System
Information Management System
A family of IBM products that consists of a database manager, transaction manager, and system services that support access to data in hierarchical databases.
Db2
IBM’s relational database product offering.
What three database models are most prevalent?
Hierarchical, network, relational, and object
Information Management System (IMS) is what model of a database system?
Hierarchical
Db2 is what model of a database system?
Relational
IMS TM
Information Management System Transaction Manager
IMS DB
Information Management System Database Manager
Information Management System Database Manager
The database
Information Management System Transaction Manager (IMS TM)
The transaction manager
What defines a hierarchical database model?
Data segments are organized in a tree structure with a parent-child relationship
Depending on the type of IMS database, the underlying data sets can be a mix of _________
VSAM and flat types
True or false
Databases can have a logical relationship between separate IMS databases?
True - however this is managed by the application
What is IMS DBs main strength?
its ability to contain large amounts of integrated data and process it quickly and efficiently.
DL/I
Data Language 1
Data Language 1
A data language
True or False
When using a DBMS, the programmer must code for logging, file locking, etc?
False
True or False
IMS programs can directly access the database?
True
Using what method can CICS programs directly access the IMS database?
CICS/DLI
What does WebSphere Application Server use to access IMS Databses?
ODBA
ODBA
Open Database Access
True of False
Db2 is unique to IBM products?
False - It’s available on Linux, UNIX, Windows and z/OS
What language is employed by Db2?
SQL - Structured Query Language
Name a few ways Db2 is accessible
Traditional transaction servers such as CICS and IMS
TSO, z/OS UNIX, or batch programs
Using WebSphere Application Server
Db2 stored procedures
Db2 Distributed Data Facility (DDF)
DDF
Db2 Distributed Data Facility
While programming Db2 is standard SQL, what are they compiled to at runtime?
Db2 calls
What considerations are needed to be made for a solid database?
Concerrency
Locking
Security
Availability
Multimedia data
Stored procedures in Java and mainframe languages
True or False
3rd party database tools can coexist with IBM data products?
True - They use basic operating system data set storage
Which data language is used to access IMS databases?
DL/1
Db2 database information is retrieved using which language?
SQL
True or False
Db2 data can be accessed using both batch and online applications
True
True or False
Db2 is a hierarchical database
False - Relational
True or False
A z/OS system could have both Db2 and IMS running at the same time
True
True or False
Db2 can only be accessed from z/OS
False - Outside of z/OS using Db2 DDF.
What is the z/OS equivalent of a file?
Datafile
File store
Database
Data set
Data store
Data mart
Dataset
What are the three traditional units of allocation used in a z/OS system?
Record
Units
Block
Cylinder
Byte
Track
Block
Cylinder
Track
z/OS allocates and maintains online data storage by using units of blocks, tracks, and cylinders.
When data set content is accessed, how is it read by the system?
An appropriate access method is used for the data set type.
An appropriate access method (such as QSAM or VSAM), which defines how the data is stored and retrieved, is used.
Which type of data set allows you to view statistics that display when members were last modified?
Partitioned data set
When browsing or editing a partitioned data set using DSLIST (option 3.4 in ISPF), a member list containing statistics is shown, including when the member was last modified.
Which DASD item contains information relating to the location of all data sets on that volume?
VTOC
To locate a dataset, the operating system will generally interrogate a z/OS catalog to find the volume where the dataset resides. Having found the correct volume, its table of contents, the VTOC, is searched to find out where exactly on this disk the dataset resides.
A PDS that is used to store source or executable code on z/OS is called what?
A library
A PDS that is used to store source or executable code on z/OS is often called a library.
Database management systems manage data stored in databases. Which of the following are two popular IBM DBMS that run on z/OS?
Db2
IMS
Db2 and IMS (or IMS Db) are the two IBM DBMs that run on z/OS. IMS TM is a part of IMS that manages transactions (not databases). IDMS is a DBMS offered by Broadcom.
Programs will use a data language to access Db2 resources. What is the name of this data language?
SQL
Structured Query Language (SQL) is used to access resources of relational databases, including Db2.
What standard data language is used to access and manage data in IMS?
DL/I is the standard data language used to access and manage data in IMS.