iX V6.5 (30391-90011)

342 Chapter7

Logging and Recovery

Logging Maintenance

:file orderssf;dev=disc

:store orders;*orderssf;online=start

>>TURBO-STORE/RESTORE VERSION C.55.07 B5152AA <<

STORE orders;*orderssf;ONLINE=START

FRI, APR 18, 1997, 12:01 PM

ONLINE BACKUP UTILIZED DISC SPACE FOR LOG ON THE FOLLOWING VOLSETS:

MPEXL_SYSTEM_VOLUME_SET : 0 KB

DATABASE INFORMATION:

TURBOIMAGE DATABASE: ORDERS .RECTOL .QALANG

FILES STORED : 7

TOTAL MEDIA WRITTEN : 1

Logging Results

All database modiﬁcations (DBPUTs, DBUPDATEs, and DBDELETEs) are logged; and in modes 1

through 4 calls to DBOPEN, DBCLOSE, DBBEGIN, DBXBEGIN, DBEND, DBXEND, and DBMEMO

are logged to the log ﬁle. Each DBBEGIN, DBXBEGIN, DBEND, and DBXEND causes a log

record to be written to the log ﬁle that includes such information as time, date, and user

buffer. These log records are used by DBRECOV to identify logical transactions.

When using TurboSTORE/iX 7x24 True-Online Backup (with ONLINE=START or

ONLINE=END option), log records designating the beginning and end of a quiesce point

triggered by True-Online backup are also written to the current log ﬁle. DBRECOV uses

these log records to determine the starting point of recovery of the database. Transactions

following the quiesce point will be used to recover the database.

Log Records

DBOPEN log records contain a time stamp recorded in the database root ﬁle, indicating the

date and the time of the last backup using DBSTORE or TurboSTORE/iX 7x24 True-Online

Backup (with ONLINE=START or ONLINE=END option) (this time stamp is referenced

by DBRECOV roll-forward recovery). DBOPEN log records also include the user identiﬁer, log

identiﬁer, and the name, group, and account of the user, database, and program.

DBUPDATE log records include both the new and the old data (before and after images);

DBDELETE includes a copy of the deleted data (before image); DBPUT includes the record

being added (after image).