Oracle Recovery internals: Basic data structure

Basic data structure

2.1 Control files

The control file contains status information for all other files in the database.

The control file contains the following types of data:

A. Database information records (one)

B. Data file records (one per data file)

C. Thread logging (one per thread). Note: One thread per instance)

D. log file Logging (one per log file)

E. File name records (one for each data file or log file member)

F. Log history (one for each completed log file)

The control file is referred to by the following document as follows, followed by the section referencing the field:

2.1.1 Database information logging (control file)

The included fields:

A Resetlogs timestamp:8.2

B Resetlogs scn:8.2

C Enabled Thread bitvec:8.3

D Force archiving scn:3.8

E. Database checkpoint thread (thread record Index): 2.13, 3.10

2.1.3 Data file record (control file)

A Thread checkpoint structure:2.12, 3.4, 8.3

B Thread-open flag:3.9, 3.11, 8.3

C Current log (LogFile record index)

D Head and tail (logfile record indices) of the list of logfiles in thread:2.8

2.1.4 Log file record (control file)

A Log sequence number:2.7

B Thread number:8.4

C Next and previous (LogFile record indices) of the list of logfiles in thread:2.8

D Count of files in group:2.8

E. Low scn:2.7

F. Next scn:2.7

G Head and tail (filename record indices) of the list of filenames in group:2.8

H. "Being cleared" flag:10.3

I. "Archiving not needed" flag:10.3

2.1.5 File name record (control file)

A FileName

B FileType

C Next and previous (filename record indices) of the list of filenames in group:2.8

2.1.6 log file history (control file)

A Thread number:2.11

B Log sequence number:2.11

C Low scn:2.11

D Low SCN timestamp:2.11

E. Next scn:2.11