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PAGES

RELATIONS

SEGMENTS

INDEXES

RDB/VMS Relational Database Operator ANALYZE — VMS RDB_3.1A

 The RDO ANALYZE statement is available for single-file databases
 only.  Use the RMU/ANALYZE command for multifile databases.

 Displays statistics on how the database is using space.  ANALYZE
 works on the database most recently invoked, and uses a read/write
 transaction.

 You can display statistics on pages, relations, indexes, or segments.

 Example:

    RDO>  ANALYZE RELATION EMPLOYEES

Additional information available:

Format

Format

 ANALYZE ─┬──> 
P

A

G

E

S
──────────────────────────┬─> ├──> 
R

E

L

A

T

I

O

N

S
─┬───────────────────┬─┤ │ └─> relation-name ──┘ │ ├┬─> 
I

N

D

E

X

E

S
──┬┬───────────────────┬─┤ │└─> 
I

N

D

I

C

E

S
──┘└─> index-name ─────┘ │ └──> 
S

E

G

M

E

N

T

S
────────────────────────┘

Additional information available:

PAGESRELATIONSSEGMENTSINDEXES

PAGES

 Rdb/VMS displays a bar chart showing page usage for the database.
 This chart indicates how many pages the database uses and how many
 pages are filled what each percentage, counted by tens.

RELATIONS

 Rdb/VMS displays a chart with the following information for each
 relation defined for the database:

  o  Total number of records
  o  Total number of bytes
  o  Average number of bytes occupied by each record
  o  Percentage of records that are fragmented (split over more than
     one database page)
  o  Percentage of total space available for a relation used to store
     users' data
  o  Percentage of total space in a relation used to store users' data

SEGMENTS

 Rdb/VMS displays a chart with the following information about the
 segmented strings stored in the database:

  o  Total number of segmented string records
  o  Total number of bytes occupied by segmented strings
  o  Average number of bytes occupied by each segmented string record
  o  Percentage of segmented string records that are fragmented (split
     over more than one database page)
  o  Percentage of total space available for a relation that is used
     to store users' data
  o  Percentage of total space in a relation used to store users' data

INDEXES

 If you use the INDEXES or INDICES option, Rdb/VMS displays a chart
 with five columns that consists of:

  o  The number of levels in the B-tree needed to store all the index
     nodes.
  o  The total number of B-tree nodes in the index.
  o  The length (number of bytes) used for the index.
  o  The number of duplicate values in the index.  This value is
     always zero in an index defined with the DUPLICATES ARE NOT
     ALLOWED clause.
  o  Any duplicate length used.

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