CA ERwin Model Manager Implementation Guide

Database ConfigurationYou should have at least four Redo log files, each 2 MB in size. A smallernumber of Redo log files or a smaller Redo log file size can cause I/Obottlenecks. If the disk space is available, using more than four Redo log filesfurther reduces the chances of delayed log switches. Larger Redo log filesimprove performance, but care must be taken to adequately schedulecheckpoints that write DMLs stored in the Redo logs to the tablespace files.If the number of disks permits, you should mirror Redo log files by creatingRedo log groups with two mirrored members per group. This offers thedatabase some protection against single disk errors.Increase Space in Redo LogsThe number and size of the Redo log files is an important performanceconsideration. Redo log files are created when the database is created.To increase space in the Redo logs1. Log in to Oracle using SQL*Plus as SYSDBA or SYSOPER and run thefollowing script to create eight Redo logs that are 2 MB each:rem -- parm1 -- temp dirrem Generate creation scriptSELECT 'ALTER DATABASE ADD LOGFILE '''|| SUBSTR ( MEMBER , 1 , INSTR ( MEMBER , '\' , -1 , 1 ) )|| 'REDO_11.LOG'' SIZE 2M ;'from V$LOGFILEwhere ROWNUM = 1and not exists ( SELECT 1 from V$LOGFILE where MEMBER like '%REDO_11.LOG' )UNIONSELECT 'ALTER DATABASE ADD LOGFILE '''|| SUBSTR ( MEMBER , 1 , INSTR ( MEMBER , '\' , -1 , 1 ) )|| 'REDO_12.LOG'' SIZE 2M ;'from V$LOGFILEwhere ROWNUM = 1and not exists ( SELECT 1 from V$LOGFILE where MEMBER like '%REDO_12.LOG' )UNIONSELECT 'ALTER DATABASE ADD LOGFILE '''|| SUBSTR ( MEMBER , 1 , INSTR ( MEMBER , '\' , -1 , 1 ) )|| 'REDO_13.LOG'' SIZE 2M ;'from V$LOGFILEwhere ROWNUM = 1and not exists ( SELECT 1 from V$LOGFILE where MEMBER like '%REDO_13.LOG' )UNION60 Implementation Guide