HP 3000 Manuals HP 3000 Manuals
CHECK BASE
Checks all data sets and all paths in the database for structural
integrity and reports any problems.
Syntax
CHE[CK] BA[SE] [ Quick]
Parameters
Quick is a fast method of checking the database to validate
pointer integrity. If you specify the Quick
parameter, the database is examined using a serial
read. Using this option, the command reports if the
database has a problem, but it does not indicate the
location.
Description
NOTE Before using the CHECK BASE command, read chapter 8, "Maintaining
the Database."
Use this command to check the database, or a specified portion of it, for
various structural integrity problems. CHECK BASE examines the root file
for incorrect path sequences, examines the data sets for inconsistent
pointers or bit maps, and examines the paths for broken chains.
The database checking process begins only after you issue the PERFORM
COMMANDS command.
Example 1
In the example below, the ORDERS database is checked using the CHECK BASE
command without the Quick parameter. A description of the output follows
the example.
>base orders
>check base
CHECK BASE (CHECK ROOT, CHECK SET and CHECK PATH) pending for 5 set(s).
>perform commands
PERFORM COMMANDS now or create job file [job/y/N]? y
Please wait ...
HP36386 (A.00.00) DBALTER (c) COPYRIGHT Hewlett-Packard Co. 1985
FRI, MAY 25, 1990, 9:03 AM
Database has been modified since last DBSTORE (DBA 220).
Continue [y/N] ? y
Checking root file.
Starting data set serial reads.
.....
Tabulating statistics.
CHECK SET (MASTER)
Pct Pct Longest Average
Master Set Name Type Entries Capacity Full Sec Cluster Cluster
-----------------------------------------------------------------------
CUSTOMER M 9 221 4 11.1 0 0.0
PRODUCT M 32 307 10 6.3 0 0.0
SUP-MASTER M 6 211 3 0.0 0 0.0
CHECK SET (DETAIL)
Pct Highest Delete
Detail Set Name Entries Capacity Full Entry Used Chain Count
-----------------------------------------------------------------------
SALES 17 504 3 17 0
INVENTORY 5 510 1 5 0
CHECK PATH
Pct
Set Name Type Max Avg Std Far Avg Packing
Search Item (PS) Chain Chain Dev Ptrs Blocks Ratio
----------------------------------------------------------------------
CUSTOMER M
SYNONYM CHAINS 1 1.00 0.00 0 1.00 N/A
PRODUCT M
SYNONYM CHAINS 2 1.07 0.25 0 1.00 N/A
SALES D
ACCOUNT ( S) 17231 2874.67 7033.14 6 1.17 6.86
STOCK# (P ) 5 2.13 1.64 6 1.13 0.89
SUP-MASTER M
SYNONYM CHAINS 1 1.00 0.00 0 1.00 N/A
INVENTORY D
STOCK# 1 1.00 0.00 0 1.00 1.00
SUPPLIER (P ) 5 5.00 0.00 0 1.00 1.00
Starting data set chained reads.
......
CHECK INFORMATION
Set Name Type
Search Item
Message(s)
------------------------------------------------------------------------
CUSTOMER M
Userlabel entry count does not match synonym chain count (CHK 570).
Record 6 is not linked into the proper synonym chain (CHK 360).
SALES D
ACCOUNT (Path 1; linked to master CUSTOMER, path 1)
Path Chain inconsistencies detected (CHK 400).
Sum of chain counts in the related master set does not
match bitmap entry count for this set (CHK 580).
Chainhead record 113 chain count mismatches entries on chain (CHK 450).
Record 3 contains bad backward pointer (CHK 440).
Record 14 contains bad backward pointer (CHK 440).
Record 15 is not linked into the proper chain (CHK 460).
Record 16 contains bad forward pointer (CHK 430).
STOCK# (Path 2; linked to master PRODUCT, path 1)
Path Chain inconsistencies detected (CHK 400).
Chainhead record 267 contains bad forward pointer (CHK 410).
Chainhead record 267 contains bad backward pointer (CHK 420).
Chainhead record 267 chain count mismatches entries on chain (CHK 450).
Record 15 is not linked into the proper chain (CHK 460).
HP36386 (A.00.00) DBCHANGE (c) COPYRIGHT Hewlett-Packard Co. 1985
>
Following is a description of the CHECK BASE output:
CHECK SET (Master) Output
Master Set Name is the name of the master data set being checked.
Type is the type of master data set being checked. A is
for automatic master; M is for manual master.
Entries is the number of entries the data set contains.
Capacity is the capacity of the data set.
Pct Full is the percentage of the data set capacity, rounded
to the nearest whole percentage, that is not
available.
Pct Sec is the percentage of secondary entries.
Longest Cluster is the longest number of TurboIMAGE/XL blocks that
must be read to find an open slot to place a synonym.
Average Cluster is the average number of TurboIMAGE/XL blocks that
must be read to find an open slot to place a synonym.
CHECK SET (Detail) Output
Detail Set Name is the name of the detail data set being checked.
Entries is the number of entries the data set contains.
Capacity is the capacity of the data set.
Pct Full is the percentage of the data set capacity, rounded
to the nearest whole percentage, that is not
available.
Highest Entry Used is the record number of the highest entry ever used
in the data set.
Delete Chain Count is the number of records in the delete chain.
CHECK PATH output
Data Set Name is the name of data set whose paths are being
checked.
Search Item Name is the name of the search item. Because master data
sets do not contain search items, but rather key
items, the text SYNONYM CHAINS appears in the field
instead. For detail data sets, the search item name
appears in the field.
Type is the data set type. Valid data set types are as
follows:
M is for manual master data sets.
A is for automatic master data sets.
D is for detail data sets.
Other codes that appear in this column are defined as
follows:
P designates primary paths.
S designates sort items.
Max Chain is the maximum number of entries in the longest
synonym or detail chain.
Avg Chain is the average number of entries per chain.
Std Dev is the standard deviation, which indicates the
accuracy of the Avg Chain statistic. The closer to
0.00 this number is, the more accurate the Avg Chain
statistic is.
Pct Far Ptrs is percent far pointers. This number is the
percentage of forward pointers that point outside the
current block.
Avg Blocks is the average number of blocks per chain.
Packing Ratio is the efficiency of the path. This is calculated by
the optimal number of blocks per chain divided by the
actual number of blocks per chain.
CHECK INFORMATION Output
The CHECK INFORMATION output contains a series of messages containing
information about inconsistencies in the database and where they occur;
that is, which data set they occur in, which record number, and so on.
Example 2
In the example below, the ORDERS database is checked using the CHECK BASE
command with the Quick parameter. A description of the output follows
the example.
>base orders
>check base quick
CHECK BASE (CHECK ROOT, CHECK SET and CHECK PATH) pending for 5 set(s).
>perform commands
PERFORM COMMANDS now or create job file [job/y/N]? y
Please wait ...
HP36386 (A.00.00) DBALTER (c) COPYRIGHT Hewlett-Packard Co. 1985
FRI, MAY 25, 1990, 9:04 AM
Database has been modified since last DBSTORE (DBA 220).
Continue [y/N] ? y
Checking root file.
Starting data set serial reads.
.....
Tabulating statistics.
CHECK SET (MASTER)
Pct Pct Longest Average
Master Set Name Type Entries Capacity Full Sec Cluster Cluster
-----------------------------------------------------------------------
CUSTOMER M 9 221 4 11.1 0 0.0
PRODUCT M 32 307 10 6.3 0 0.0
SUP-MASTER M 6 211 3 0.0 0 0.0
CHECK SET (DETAIL)
Pct Highest Delete
Detail Set Name Entries Capacity Full Entry Used Chain Count
-----------------------------------------------------------------------
SALES 17 504 3 17 0
INVENTORY 5 510 1 5 0
CHECK PATH
Pct
Set Name Type Max Avg Std Far Avg Packing
Search Item (PS) Chain Chain Dev Ptrs Blocks Ratio
----------------------------------------------------------------------
CUSTOMER M
SYNONYM CHAINS 1 1.00 0.00 0 1.00 N/A
PRODUCT M
SYNONYM CHAINS 2 1.07 0.25 0 1.00 N/A
SALES D
ACCOUNT ( S) 17231 2874.67 7033.14 6 1.17 6.86
STOCK# (P ) 5 2.13 1.64 6 1.13 0.89
SUP-MASTER M
SYNONYM CHAINS 1 1.00 0.00 0 1.00 N/A
INVENTORY D
STOCK# 1 1.00 0.00 0 1.00 1.00
SUPPLIER (P ) 5 5.00 0.00 0 1.00 1.00
Starting data set chained reads.
CHECK INFORMATION
Set Name Type
Search Item
Message(s)
------------------------------------------------------------------------
ROOT FILE
Root file inconsistency in area other than path sequence. This
cannot be fixed by DBChange (CHK 220).
CUSTOMER M
Userlabel entry count does not match synonym chain count (CHK 570).
SALES D
ACCOUNT (Path 1; linked to master CUSTOMER, path 1)
Path Chain inconsistencies detected (CHK 400).
Sum of chain counts in the related master set does not
match bitmap entry count for this set (CHK 580).
STOCK# (Path 2; linked to master PRODUCT, path 1)
Path Chain inconsistencies detected (CHK 400).
HP36386 (A.00.00) DBCHANGE (c) COPYRIGHT Hewlett-Packard Co. 1985
>
The output for the CHECK BASE command using the Quick parameter is the
same as the standard CHECK BASE command; however, a summary version of
the standard CHECK INFORMATION output is displayed. Problems are
identified, but the specific location and records that need fixing are
not isolated.