Calculation Parameters for Examples

Provides the calculated values derived by using the formulas for calculating the disk queue size.

These calculations use these assumptions about the example replication system:

  • Tables T1 and T2 are in database DB1.

  • Table T3 is in database DB2.

  • All three tables are replicated to sites S1, S2, and S3.

  • Not all messages are replicated to all sites.

Table Parameters

Database

Table

# Cols

Columns Changed

Change Rate (num/sec)

Row Width (bytes)

Row Width Changed

# Sites

DB1

T1

10

5

20

200

100

3

DB1

T2

10

5

10

400

200

2

DB2

T3

120

100

2

1500

1000

2
Site Parameters—Table Replication Selectivity

Table

Percent of Updates to S1

Percent of Updates to S2

Percent of Updates to S3

T1

10%

40%

40%

T2

40%

80%

0%

T3

20%

0%

20%
Transaction Rates

Transaction Rate

DB1

DB2

S1

S2

S3

Inbound

20/sec

20/sec

-

-

-

Outbound

-

-

5/sec

10/sec

8/sec
Parent topic: Example Queue Usage Calculations