System Architecture 2-7
In This Chapter
In this guide,system architecture is interpreted broadly to include OnLine
database server processes as well as OnLine shared memory and disk data
structures.This chapter provides optional reference material about OnLine 5.x
operation that is intended to deepen your understanding. Topics in other
chapters contain cross-references to specific topics in this chapter if
additional information could prove helpful for understanding.
OnLine system architecture can be separated into two major categories:
Shared memory
Disk data structures
Thefirst half of this chapter covers shared-memory topics. The second half of
thischapter, which begins on page 2-81, describes information related to the
disk data structures.
Initialization
OnLine initialization refers to two related activities: shared-memory initial-
ization and disk-space initialization. To initialize OnLine, you execute the
tbinit process. You can do this directly from theUNIX command line or
indirectlyvia DB-Monitor. The options you include in the tbinit command or
the option you select fromDB-Monitor determines the specific initialization
procedure thattbinit executes.
Referto page 2-10for a detailed description of what happens during shared-
memory initialization.
Refer topage 2-14 for a detailed description of what happens during disk-
space initialization.