4-2 IBM Informix OnLine Database Server Administrator’s Guide
What Happens During Logical Log Backup .......... 4-26
Ready LTAPEDEV.................. 4-27
Locate the Next Logical Log .............. 4-27
Copy Blobpages .................. 4-27
Place Log Header on Tape ............... 4-28
Write Log Records to Tape ...............4-29
Write Trailer Page ..................4-30
What Happens During an Archive ............. 4-30
Read Archive History Information ............ 4-31
Mount a Tape on TAPEDEV ..............4-31
Verify the Archive Level................ 4-32
Check Free Space in the Logical Log............ 4-32
Force a Checkpoint ................. 4-32
Purpose of Checkpoint Timestamp........... 4-33
Purpose of Data Snapshot ..............4-33
Synchronize tbtape and tbinit Activities ..........4-33
Archive Disk Pages ................ 4-34
Archive blobpages ................ 4-35
Write Tape Header Page................ 4-35
Archive Reserved Pages ................ 4-36
Determine Archive Criteria............... 4-37
Archive Disk Pages That Meet Criteria........... 4-38
Monitor and Archive Physical Log Pages .......... 4-38
Write a Trailer Page .................4-38
Update the Reserved Pages............... 4-38
Fast Recovery..................... 4-39
How Does OnLine Initiate Fast Recovery? ......... 4-39
Fast Recovery and Logging............... 4-40
Step 1: Checkpoint Condition .............. 4-41
Step 2: Find Checkpoint Record in Logical Log ........ 4-41
Step 3: Roll Forward Log Records ............ 4-43
Step 4: Roll Back Incomplete Transactions.......... 4-44
Data Restore: When Should You Do It? ............ 4-45
Steps That Occur During a Data Restore .......... 4-45
Gather All Tapes Needed for Restore ...........4-47
Verify OnLine Configuration .............. 4-48