Databases Reference
In-Depth Information
We begin by withdrawing the affected versions. The transac-
tion specifies the timespan [Jul 2010 - Jul 2011]. Part of version
8, and all of versions 5 and 3, [
fill
1
] this timespan. So the first
step is to withdraw these three versions. Since no assertion begin
date was explicitly specified on the transaction, that date
defaults to Now(), January 2012. The result is shown in
Figure 10.10
. Using a convention described previously, we
enclose in angle brackets the row numbers of all rows which
are part of this atomic, isolated unit of work and, because these
rows are now withdrawn, we show them shaded.
Only part of row 2 (version 8) [intersects] the range of the
transaction. Since row 2 has been withdrawn into past assertion
time, the next thing we must do is to replace, in current assertion
time, that part of the version that the transaction is not
concerned with. To do this, the AVF creates a version whose
effective time period extends from version 8's effective begin
date up to the effective begin date of the transaction, July 2010.
The result is row 7, shown in
Figure 10.11
.
The rest of version 8 does [
fill
1
] the range of the transaction,
as do all of versions 5 and 3. The versions which take the place of
these two versions are not replacements, because they do not
contain identical business data. Instead, they are versions which
supercede the original versions with the new business data. To
supercede these versions, the AVF first creates a version whose
effective time period extends from the transaction's effective
begin date up to the effective end date of version 8. The result
is row 8, shown in
Figure 10.12
.
Jan12
UPDATE Policy [P861, , , $40] Jul 2010, Jul 2011
Jan
2010
Row
#
1
<2>
<3>
Jan
2011
Jan
2012
Jan
2013
Jan
2014
eff-beg
asr-beg
oid
eff-end
asr-end
epis-
beg
client
type
copay
row-crt
P861
Feb10
Apr10
Oct10
Feb10
9999
Jan10
C882
HMO
$15
Feb10
P861
P861
P861
P861
P861
Apr10
Mar10
Jan12
Jan10
C882
C882
C882
C882
C882
HMO
$20
$20
Apr10
Apr11
Jul11
9999
Apr11
Jan12
Apr11
Apr11
PPO
Apr11
4
Jul11
Jul11
9999
HMO
HMO
$15
Jul11
<5>
Jan11
Mar11
Aug11
Jan12
Jan11
Jan10
$20
$20
Aug11
6
Jan10
Feb10
Oct11
9999
PPO
Oct11
Figure 10.10 Updating a Policy: Withdrawing the Versions in the Target Range.
