User Guide

SAP AG November 2002
LOG_IO_QUEUE
The special database parameter [Page 80] LOG_IO_QUEUE denotes the size of the log
queue [Page 45] in pages [Page 46].
LOG_MODE
The general database parameter [Page 79] LOG_MODE denotes the log mode [Page 143].
• SINGLE: Log entries are saved to a single log area [Page
142]
• DUAL: Log entries are saved to two log areas in parallel
LOG_SEGMENT_SIZE
The general database parameter [Page 79] LOG_SEGMENT_SIZE denotes the size of a log
segment in the log area [Page
142] in pages.
For interactive backups [Page 139], the log segment size determines the size of the segments
that the redo log entries [Page 44] are saved to. It also determines the intervals at which log
areas are backed up automatically [Page 126].
The size of the log segment depends on the size of the individual log volumes [Page 144] and
must not be greater than the sum of all log volumes.
User-defined value Log segment sizes used by the system
No definition of log segment size
(LOG_SEGMENT_SIZE = 0)
A third of the total log area.
The log segment size in pages is smaller than or
the same as 50% of the title log area.
The defined value for LOG_SEGMENT_SIZE.
The log segment > 50% of the total log area. 50% of the log area.
LRU_FOR_SCAN
The special database parameter [Page 80] LRU_FOR_SCAN governs where data pages that
have been scanned into the data cache [Page 130] are placed in the LRU (last recently used)
list.
• no (default setting): The data pages scanned into the data cache are placed at the end of
the LRU list. This means the data pages will removed from the data cache promptly if
new entries are made in the LRU list.
• yes: The data pages scanned into the data cache remain in the same place in the LRU
list as they were before the scan.
MAXARCHIVELOGS
See MAXLOGVOLUMES [Page 86]
User Manual: SAP DB 84