A sequence is a database object that automatically generates
unique key values. A sequence can generate one value at a time or
can generate a cache of multiple values. The use of sequence caches
improves system performance because processes can obtain values from
the cache without waiting for the sequence to generate individual
values.
About this task
The maxseq sequence is used to generate values for the
rowstamps column in database tables. Because the rowstamps column
requires values frequently, set the sequence cache size for maxseq
to 500. For all other sequences, set the sequence cache size to 50.
If IBM®
Tivoli® Asset Management for IT is
installed, you must remove some specified sequence names from your
SQL script because those sequences must not be altered manually.
Procedure
- Run the following command to generate a script file that
contains the SQL statements to set the sequence cache size:
| Option |
Description |
|---|
| If you are using Db2® |
db2 "select ’alter sequence maximo.’ || sequencename
|| ’ cache 50 ;’ from maximo.maxsequence" > change_seq_cache.sql |
| If you are using Oracle |
sqlplus "select ’alter sequence maximo.’ || sequencename
|| ’ cache 50 ;’ from maximo.maxsequence" > change_seq_cache.sql |
- Edit the change_seq_cache.sql file
to change the sequence cache size for the maxseq sequence to 500.
- If Tivoli
Asset Management for IT is
installed, edit the change_seq_cache.sql file
to remove any entries that match the following sequence names:
Table 1. Sequences to remove from the change_seq_cache.sql file
| Sequence cache name |
Sequence cache name |
Sequence cache name |
| ASSETATTRIBUTESEQ |
DPADISKSEQ |
DPAMSWSUITECOMPSEQ |
| CDMCITYPESSEQ |
DPADISPLAYSEQ |
DPAMSWSUITESEQ |
| CLASSANCESTORUSEQ |
DPAFILESEQ |
DPAMSWUSAGERANGESEQ |
| CALSSSPECSEQ |
DPAIMAGEDEVICESEQ |
DPAMSWUSAGESEQ |
| CLASSSPECUSEWITHSEQ |
DPAIPXSEQ |
DPAMSWVARIANTSEQ |
| CLASSSTRUCTURESEQ |
DPALOGICALDRIVESEQ |
DPANETADAPTERSEQ |
| OMPSEQ |
DPAMADAPTERSEQ |
DPANETDEVCARDSEQ |
| RELATIONRULESSEQ |
DPAMADPTVARIANTSEQ |
DPANETDEVICESEQ |
| RELATIONSEQ |
DPAMEDIAADAPTERSEQ |
DPANETPRINTERSEQ |
| ACTCIRELATIONSEQ |
DPAMMANUFACTURERSEQ |
DPAOSSEQ |
| ACTCISEQ |
DPAMMANUVARIANTSEQ |
DPASOFTWARESEQ |
| ACTCISPECSEQ |
DPAMOSSEQ |
DPASWSUITESEQ |
| DEPLOYEDASSETSEQ |
DPAMOSVARIANTSEQ |
DPATCPIPSEQ |
| DPACOMMDEVICESEQ |
DPAMPROCESSORSEQ |
DPAUSERINFOSEQ |
| DPACOMPUTERSEQ |
DPAMPROCVARIANTSEQ |
OMPCIRLNSEQ |
| DPACPUSEQ |
DPAMSOFTWARESEQ |
|
- Run the SQL script on the database to change the sequence
cache values.