IBM 000-8697 Bedienungsanleitung PDF herunterladen (Seite 107)

100

101

System Architecture 2-13

What Happens During Shared-Memory Initialization

Duringshared-memoryinitialization,diskstructuresanddisklayoutarenot

affected. Essential address information (such as the locations of the logical

and physical logs) is read from disk. These addresses are used to update

pointers in shared memory.

Step 5: Wake Parent Process

After the tbinit daemon updates all pointers, it wakes the parent tbinit

process and writes a “shared-memory initialization complete” message in

theOnLinemessagelog (speciﬁedas

MSGPATHintheconﬁgurationﬁle).The

prompt returns to the user at this point, and any error messages that might

havepassedfromthedaemontotheparentprocessaredisplayed.Theparent

process goes away at this point. Its role is ended.

Steps 6 and 7: Initiate Fast Recovery and First Checkpoint

Shared memory is initialized. The tbinit daemon initiates fast recovery.

(Refer to page 4-39 for further information about fast recovery.)

After fast recovery executes,tbinit initiates acheckpoint. (Referto page 2-70

for further information about checkpoints.) As part of the checkpoint

procedure (page 2-72), tbinit checks the database tblspace index to verify

that all database names are unique. (Refer to page 2-107 for further infor-

mation about the database tblspace.)

After the checkpointcompletes, thedaemon writes a“checkpoint complete”

message in the OnLine message log.

OnLine is in quiescent mode.

Step 8: Drop Temporary Tables (Optional)

The tbinit daemon begins a search through all dbspaces for temporary

tblspaces. (If you executed tbinit with the -p option, tbinit skips this step.)

These temporary tblspaces would have been left by user processes that died

prematurely and were unable to perform proper cleanup. Any temporary

tblspaces are deleted and the disk space is reclaimed.

1 2 ... 102 103 104 105 106 107 108 109 110 111 112 ... 701 702

Kommentare zu diesen Handbüchern

Keine Kommentare

IBM 000-8697 Bedienungsanleitung Seite 107

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Datenbanksoftware IBM 000-8697