IBM 000-8697 - page 97

System Architecture 2-3
LRU Queues and Buffer Pool Management..........2-58
LRU_MAX_DIRTY.................2-59
LRU_MIN_DIRTY .................2-59
How a User Process Acquires a Buffer ...........2-60
Step 1: Identify the Data ...............2-61
Step 2: Determine Lock-Access Level ..........2-61
Step 3: Locate the Page in Memory ...........2-61
Step 4: Read the Page in from Disk ...........2-62
Steps 5-7: Lock Buffer, Release Lock, and Wake
Waiting Processes ..............2-62
Physical Log Buffer ..................2-63
Double Buffering .................2-64
Causes of Flushing .................2-64
Flushing a Full Buffer ................2-65
Logical Log Buffer ..................2-66
Triple Buffering ..................2-66
Buffer Contents ..................2-68
Causes of Flushing .................2-68
Flushing a Full Buffer ................2-69
OnLine Checkpoints .................2-70
Main Events During a Checkpoint ...........2-70
Initiating a Checkpoint ...............2-70
Fast Recovery...................2-71
Archive Checkpoints ................2-71
What Happens During a Checkpoint ............2-72
When the Daemons Flush the Buffer Pool ..........2-73
How OnLine Synchronizes Buffer Flushing..........2-74
Write Types Describe Flushing Activity ...........2-75
Sorted Write ...................2-76
Idle Write ....................2-76
Foreground Write .................2-77
LRU Write....................2-77
Chunk Write ...................2-77
Big-Buffer Write..................2-78
Writing Data to a Blobspace ...............2-78
Disk Data Structures ...................2-81
OnLine Disk Space Terms and Definitions ..........2-81
Chunk .....................2-82
Page ......................2-82
Blobpage ....................2-84