Shulou(Shulou.com)06/01 Report--

1 Oracle Startup option

When the Oracle database starts with startup, Oracle looks for the initialization parameter file in the default location $ORACLE_HOME/dbs; Oracle looks for the appropriate initialization file in the following order:

Spfile$ORACLE_SID.ora

Spfile.ora

Init$ORACLE_SID.ora

You can start the oracle database in several ways. Different startup methods will affect the degree of starting the database. The startup status is nomount (database not loaded)-> mount (database load completed)-> open (database open).

1.1 STARTUP NOMOUNT

SQL > startup nomountORACLE instance started.Total System Global Area 1603411968 bytesFixed Size 2253664 bytesVariable Size 1375734944 bytesDatabase Buffers 218103808 bytesRedo Buffers 7319552 bytes

Oracle reads the parameter file, opens the instance, starts the Oracle background process, and assigns SGA to Oracle. At this point, the database status is unmounted.

1.2 ALTER DATABASE MOUNT

SQL > alter database mount;Database altered.

Oracle opens and reads the control file to get the name and location of the data file and the redo log file. At this point, the database finishes loading.

1.3 ALTER DATABASE OPEN

SQL > alter database open;Database altered.

Oracle opens data files and redo log files, so Oracle can provide services to the outside world.

2 View the internal startup process through the 10046 event

SQL > startup nomount;Total System Global Area 1603411968 bytesFixed Size 2253664 bytesVariable Size 1375734944 bytesDatabase Buffers 218103808 bytesRedo Buffers 7319552 bytesSQL > oradebug setmypidStatement processed.SQL > oradebug tracefile_name/oracle/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_3682.trcSQL > alter session set events'10046 trace name context forever,level 12 session altered.SQL > alter database mount;Database altered.SQL > alter database open;Database altered.

View the udump file

[oracle@rhel6 ~] $more / oracle/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_3682.trcTrace file / oracle/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_3682.trcOracle Database 11g Enterprise Edition Release 11.2.0.4.0-64bit ProductionWith the Partitioning, OLAP Data Mining and Real Application Testing optionsORACLE_HOME = / oracle/app/oracle/product/11.2.0System name: LinuxNode name: rhel6Release: 2.6.32-431.el6.x86_64Version: # 1 SMP Sun Nov 10 22:19:54 EST 2013Machine: x86_64VM name: VMWare Version: 6Instance name: orcl

Oracle database mount starts reading control files and writing log files

... WAIT # 140528657591192: nam='control file sequential read' ela= 8 file#=0 block#=1 blocks=1 obj#=-1 tim=1502627703012561WAIT # 140528657591192: nam='control file sequential read' ela= 2 file#=1 block#=1 blocks=1 obj#=-1 tim=1502627703012583WAIT # 140528657591192: nam='control file sequential read' ela= 47 file#=0 block#=3 blocks=8 obj#=-1 tim=1502627703012650WAIT # 140528657591192: nam='control file sequential read' ela= 13 file#=1 block#=3 blocks=8 obj#=-1 tim=1502627703012674...WAIT # 140528657591192: nam='ADR block file read' ela= 847 = 0 = 0 obj#=-1 tim=1502627707123048WAIT # 140528657591192: nam='ADR block file read' ela= 576 = 0 = 0 = 0 obj#=-1 tim=1502627707124068WAIT # 140528657591192: nam='ADR block file read' ela= 562 = 0 = 0 = 0 obj#=-1 tim=1502627707125013WAIT # 140528657591192: nam='ADR block file read' ela= 473 = 0 = 0 = 0 obj#=-1 tim=1502627707125891...

The Oracle database open process reads the control file information and compares it with the disk data file header.

Alter database openEND OF STMTPARSE # 140528657591192 PUBLIZOGRAPHIOGRAPHY 274 PUB0MIZOGRAPHY 0MIZOMIHY 0MIHULING 1DIREDIZOREOLOGICOLOGY Tim=1502627713479605WAIT # 140528657591192: nam='control file sequential read' ela= 8 file#=0 block#=1 blocks=1 obj#=-1 tim=1502627713479904WAIT # 140528657591192: nam='control file sequential read' ela= 4 file#=1 block#=1 blocks=1 obj#=-1 tim=1502627713479922WAIT # 140528657591192: nam='control file sequential read' ela= 2 file#=0 block#=15 blocks=1 obj#=-1 tim=1502627713479931...WAIT # 140528657591192: nam='Disk file operations I ela= 11 FileOperation=2 fileno=1 filetype=2 obj#=-1 tim=1502627713481300WAIT # 140528657591192: nam='Disk file operations I ela= 6 FileOperation=2 fileno=2 filetype=2 Obj#=-1 tim=1502627713481317WAIT # 140528657591192: nam='Disk file operations I ela= 4 FileOperation=2 fileno=3 filetype=2 obj#=-1 tim=1502627713481327WAIT # 140528657591192: nam='Disk file operations I ela= 4 FileOperation=2 fileno=4 filetype=2 obj#=-1 tim=1502627713481338WAIT # 140528657591192: nam='Disk file operations I FileOperation=2 fileno=201 filetype=2 obj#=-1 tim=1502627713481351 O'ela= 5

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