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Catalog tables
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Directory
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Logs
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BSDS
Catalog tables
o
We used to have more than 120+ tables in a system
o
Each tables have specific functions
o
We need system Authority (SYSADM/DBADM) to use
catalog tables
System tables
Maintains high level information about tables, table owners,
schema, created date, respective Table
spaces,DB,Any existing foreign key. While querying tables we use schema names,
since we are using logical objects.
SYSIBM.SYSTABLES
SYSIBM.SYSTABLESPACES
SYSIBM.SYSDATABASES
SYSIBM.SYSCOPY
SYSIBM.SYSUSERALL
SYSIBM.PLANS
ETC..,
Directory blocks
We use less than 10 blocks
Non accessible using SQL
To access IBM supplied rexx required.
SKCT01 - pkg table
SKPT01 - Plan table
SYSLRGX - stores information about compiled
plan/pkgs including access paths
SYSUTILX - Have entry of utilities which we
run on a system
Note : Commited work units only will be
available in SYSCATALOG / DIRECTORY
LOGS
Logs will have entries with timestamps and RBA value for
each entry mainly used for recovery
LOG STATUS
ACTIVE - in use
Archieve - offloading(old logs)
Archieve logs will reside in tapes often , depends on cost
factor of shops.
Active logs must reside in DASD,to enable fast access.we can
32 active log dataset to a DB.
Dual
Copy
Each
active log dataset will have a backup copy for the datace redundancy.Having a
backup of existing datasets.
We can use force offload command to make active to archive
logs.
Jobs should commit or offloading will not take place.So all
active queries should comit before offloading.
BSDS
Boot Strap Data Set
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Inventory of logs
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It holds details about RBA range the archieve
log datasets archieved.
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We can use DSNJU004 to get information about
logs.Its a separate physical datasets.
HLQ.BSDS01
HLQ.BSDS02
Utilities
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Online utilities
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Offline utilities (stand alone utilities)
Utilities will be provided by IBM as well as different vendors .
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