Databases Reference
In-Depth Information
client
Row
#
oid
eff-beg
eff-end
asr-beg
asr-end
epis-
beg
type
copay
row-crt
1
2
3
4
5
6
7
8
<9>
<10>
P861
Feb10
Apr10
Apr10
Feb10
Mar12
Jan10
C882
C882
C882
C882
C882
C882
C882
C882
C882
C882
HMO
HMO
$15
Feb10
Apr10
Apr11
Jul11
P861
P861
P861
P861
P861
P861
P861
P861
P861
Oct10
Mar10
Jan12
Jan12
Jan10
$20
$20
Apr11
Jul11
9999
Apr11
Apr11
Apr11
PPO
Jul11
Jul11
9999
HMO
HMO
$15
Jan11
Mar11
Aug11
Jan12
Jan11
Jan10
Jan10
Jan10
$20
$20
$20
$40
$40
$40
Aug11
Jan10
Feb10
Oct11
Mar12
Mar12
Mar12
May12
May12
PPO
Oct11
Apr10
Jul10
Jan12
HMO
HMO
Jan12
Jan12
Jan12
Jan12
Jan12
Jul10
Oct10
Apr11
Jul11
Jan12
Jan12
Apr11
PPO
Jan11
Mar11
Jan11
HMO
Figure 10.16 Shortening an Episode Forwards: After Step 1.
Because the delete transaction {shortens Episode B forwards},
it alters the episode begin date. Specifically, it changes that begin
date from April 2011 to May 2011. This transaction will require
all three of the physical transaction steps shown in
Figure 10.13
.
The first physical transaction step withdraws versions 9 and
10. The result is shown in
Figure 10.16
. These versions have been
withdrawn, as all versions are, by overwriting their assertion end
dates. The overwrites which withdraw rows into past assertion
time do not lose information, however, as overwrites of business
data do. This is because we always know what the assertion end
date was before the row was withdrawn. In all cases, it was
12/31/9999. This is guaranteed because (i) all versions are cre-
ated with an assertion end date of 12/31/9999, and (ii) the AVF
will never alter an assertion end date that is not 12/31/9999.
In comparing the transaction's time period to that of the epi-
sode, we see that it completely includes version 10 but only
[overlaps] version 9. So, having withdrawn version 9, we must
now replace it with a version identical to it except that its effec-
tive time period begins on May 2011. But because version 9 is
the first version of Episode B, it changes the episode begin date
of the episode from April 2011 to May 2011. This, in turn, affects
version 4, which is the second version in that episode. Conse-
quently, we must withdraw version 4, and replace it with a ver-
sion that is identical to it except for having the new episode
begin date. The result of all this work is shown in
Figure 10.17
.
Episode C has been {erased}, completely withdrawn into past
assertion time. Episode B has been {shortened forwards} by one
month.
The first delete transaction we considered covered an entire
episode, {removing} that episode by withdrawing all its versions
into past assertion time. This delete transaction, however, left part
