IBM 000-8697 사용자 설명서

2-140

IBM Informix OnLine Database Server Administrator’s Guide

Structure of an Index Page

Figure 2-35

To aid

understanding, this

figure uses last

names and

customer numbers

as index key values

instead of a bytes

part and a rowid.

The

Tsonga

root-

page entry

represents a single-

byte value and

rowid, indicating

the first entry on a

branch page. The

Smith

root-page

entry represents a

byte value, rowid,

and two page

addresses,

indicating a range

of pages that

contain rowids for

the same byte

value. The last

entry,

1099

represents the

infinity slot.

256, 385, 786, 646,
611, 577...

Last Name
(lname)

Customer number
(customer_num)

Smith

148, 193, 232, 256, 385, 459,
475, 513, 542, 577, 598, 611,
639, 646, 773. 786,790,821

Tsonga

523

Watson

106

Smith 542, 639, 790,
148, 232, 193...

Tsonga 523

Tsonga 1087

Smith 542 1054 1056

1099

459, 475, 513,
193, 821

Watson 106

Root node index page

Branch node index pages

Address 1054

Address 1087

Address 1099

Address 1056