Technical data

Configuration Guidelines
4-4 Oracle Utilities Meter Data Management Database Administrator’s Guide
Storage Recommendations
This section specifies recommended options for storing the database objects.
SecureFile for Storing LOBs
Beginning with Oracle 11g, tables having fields with data type of CLOB or BLOBS should have
the LOB Columns stored as SecureFiles.
• The storage options with SecureFiles for Heap Tables should be ENABLE STORAGE IN
ROW, CACHE and COMPRESS.
• For the IOT Table the PCTTHRESHOLD 50 OVERFLOW clause should be specified and
the storage options with SecureFiles should be ENABLE STORAGE IN ROW, CACHE and
COMPRESS.
• The PCTTHRESHOLD should be specified as a percentage of the block size. This value
defines the maximum size of the portion of the row that is stored in the Index block when an
overflow segment is used.
• The CHUNK option for storage, which is the data size used when accessing or modifying
LOB values, can be set to higher than one database block size if big LOBs are used in the IO
Operation.
• For SecureFiles, make sure that the initialization parameter db_securefile is set to
PERMITTED (the default).
• The Tablespace where you are creating the SecureFiles should be enabled with Automatic
Segment Space Management (ASSM). In Oracle Database 11g, the default mode of
Tablespace creation is ASSM so it may already be set for the Tablespace. If it's not, then you
have to create the SecureFiles on a new ASSM Tablespace.
Note: To enable compression on SecureFiles, you must have an Oracle
Advanced Compression license in addition to Oracle Database Enterprise
Edition. This feature is not available for the standard edition of the Oracle
database.
If you are using Oracle Database Enterprise Edition, please ensure that the
“COMPRESS” flag is turned on by setting it to “Y” in Storage.xml.
See Database Syntax on page 4-5 for more information on SecurFiles.
Database Configuration Recommendations
This section specifies the recommended methods for configuring the database with a focus on
specific functional area.
Large Redo Log File Sizes
The Redo Log files are written by the Log Writer Background process. These Log files are written
in a serial manner. Once a Log File is full, a Log Switch occurs and the next Log file starts getting
populated.
It is recommended that the size of the Redo Log files should be sufficiently high so that you do
not see frequent Log Switches in the Alert logs of the database. Frequent Log Switches impact the
IO performance and can be avoided by having a larger Redo log File size.
Frequent Log Switches impacts the IO performance and can be avoided by having a bigger Redo
log File Size.