Oracle NoSQL Database Cloud Service offers two capacity pricing modes: ondemand capacity and provisioned capacity.
The ondemand pricing model frees you from provisioning the write and read capacity in advance. Oracle NoSQL Database Cloud Service dynamically adjusts the capacity needed by your application in realtime. Billing is based on your application’s actual write and read capacity consumed.
Product

Unit price

Metric

Oracle NoSQL Database Cloud–Write–Auto


Write unit per month*

Oracle NoSQL Database Cloud–Read–Auto


Read unit per month*

Oracle NoSQL Database Cloud–Storage


GB storage capacity per month*

Oracle NoSQL Database Cloud  Regional Replicated Write 
Write Unit Per Month 
* See Metric Description for details.
Per the service description (PDF), the metrics are defined as below:
One Write or Read Unit Per Month measures the total consumption of 2,678,400 KB of writes or reads per month (744 hours).
Since there are 2,678,400 seconds in a month:
Your application workload characteristics may vary dynamically and consume a different number of write or read units per month; you will be billed accordingly per your Oracle NoSQL Database Cloud consumption.
In addition to writes and reads, storage is another resource required. Storage capacity is provisioned in advance. Capacity can vary within a month; it is measured and billed based on the number of GB capacity provisioned.
Consider an application that performs some write and read operations in different periods of a month and consumes the following write and read:
Assumptions
Assume the following for simplicity:
Here's a sample of the monthly billing, assuming both workloads result in the same total amount of write and read units consumed for the 31 days.
Billing example for both workloads in a month (31 days)
Writes  

Workload period  Daily write workload  Total writes consumed for each period  Details 
Day 1–5  100,000  500,000  100,000 writes x 5 days 
Day 6–15  250,000  2,500,000  250,000 writes x 10 days 
Day 16–31  45,000  720,000  45,000 writes x 16 days 
Monthly total  3,720,000  
Monthly total write units  1.39  3,720,000/2,678,400  
Monthly billing  $4.35  3,720,000/2,678,400 x $3.135 
Reads  

Workload period  Daily read workload  Total reads consumed for each period  Details 
Day 1–5  100,000  500,000  100,000 reads x 5 days 
Day 6–15  250,000  2,500,000  250,000 reads x 10 days 
Day 16–31  45,000  720,000  45,000 reads x 16 days 
Monthly total  3,720,000  
Monthly total read units  1.39  3,720,000/2,678,400  
Monthly billing  $0.22  3,720,000/2,678,400 x $0.16 
Storage  

Total storage GB read units  Monthly billing  Details  
Day 1–31  5  $0.33  5 GB x $0.066 
Total monthly billing
$4.91 (Write, read, and storage) 
Note: The total monthly billing number is rounded. There will be some slight differences if you simply total the numbers in the examples using a calculator.
Ondemand capacity model bills are based on the total number of read and write units consumed by your application over a month. The example below assumes that you have the following two vastly different workloads: one is continuous with various peaks and troughs, and the other is spiky with abrupt pauses. Both consume the same number of write and read units over a month. The areas under each workload curve represent the total number of write and read units consumed and are the same. Therefore, the monthly costs will also be the same.
Example 1: Various continuous write/read operations in a month
Days 1 to 5 have continuous, medium write/read workloads compared to Days 6 to 15 with higher workloads. Days 16 to 31 have continuous, lowest write/read workloads among the three different periods.
Example 2: Unpredictable sudden spike in write/read operations in a month
Days 1 to 5 have one spike with medium write/read workloads. Then, there is a rest period before Days 6 to 15 which have three spikes with higher write/read workloads and shorter rests in between. Days 16 to 31 have the lowest write/read operations with three smaller spikes and longer rests in between.
The provisioned pricing model enables you to reserve the write and read capacity limits in advance per the needs of your application. Oracle NoSQL Database Cloud Service will provision the capacity to meet the workload requirements. Billing is based on the write and read capacity reserved by your application.
Product 
Unit Price 
Metric 
Oracle NoSQL Database Cloud–Write 
Write unit per month* 

Oracle NoSQL Database Cloud–Read 
Read unit per month* 

Oracle NoSQL Database Cloud–Storage 
GB storage capacity per month* 
* See Metric Description for details.
Per the service description (PDF), the metrics are defined as below:
One Write or Read Unit Per Month provides the opportunity to perform 2,678,400 1 KB writes or reads over the course of a month at an interval of one per second. If your table requires multiple writes or reads per second, allocating greater than 1 Write or Read Unit Per Month is required.
Storage capacity is metered and billed based on the number of GB capacity provisioned throughout a month. Capacity can vary within a month; Oracle NoSQL Database will be billed accordingly.
Below are a few billing examples with different workload patterns and provisioned capacities. We will learn how the monthly billing may be calculated using the quickest and easiest methods to understand. We will explore different billing calculations where capacities fluctuate on a monthly or even an hourly basis. Since write, read, and storage capacities provisioned are metered at persecond granularity, users have the flexibility to calculate using other unit prices, e.g., per minute, per hour.
Use monthly and hourly unit prices for the examples. To derive the hourly unit price, divide the monthly unit price by 744 hours. Hourly price is ideal when the workload changes on an hourly basis.
Pricing and metrics for billing examples
Product  Unit Price Per Month  Unit Price Per Hour 

Oracle NoSQL Database Cloud—Write  $0.1254  $0.0001685 
Oracle NoSQL Database Cloud—Read  $0.0064  $0.0000086 
Assumptions
Assume the following for simplicity:
Below are three examples with different workloads, provisioned capacities, and billing calculation methods.
Example 1: Predictable, continuously consistent workload and provisioned capacities in a month
Assume your application performs a pretty consistent number of write and read operations for the entire month. The workloads are continuous and only slightly vary for the entire month, enabling monthly consistent capacities provisioned for writes and reads. Capacities are provisioned for the workload's small peak at the middle of the month. Assume the storage provisioned on Day One stays constant at 25 GB (with time to live enabled) throughout the month.
Unit Price Per Month is the best method for calculating the monthly billing since the provisioned write and read capacities and storage are consistent throughout the month.
Days 1 to 31 have consistent workload with minimal changes across the month. Provisioned write and read capacities are at 200 KB/sec (200 Write/Read Units) to meet the peak at the middle of the month.
Monthly bill = (Write/Read Unit provisioned) x (Write/Read Monthly Unit Price) 
Writes  

Workload period  Write units  Monthly billing  Details 
Day 1–31 (Write 200 KB/sec)  200  $25.08  200 writes x $0.1254 
Reads  

Workload period  Read units  Monthly billing  Details 
Day 1–31 (Read 200 KB/sec)  200  $1.28  200 reads x $0.0064 
Storage  

Total storage GB  Monthly billing  Details  
Day 1–31  25  $1.65  25 GB x $0.066 
Total monthly billing $28.01 (Write, read, and storage) 
Note: The total monthly billing number is rounded. There will be some slight differences if you simply total the numbers in the examples using a calculator.
Example 2: Dynamic, continuous workloads and provisioned capacities in a month
Assume your application performs various write and read operations for different periods within the month. Each workload is different for the following periods:
Assume the write and read capacities changes occur at midnight. Also, assume the storage provisioned on Day One stays constant at 25 GB (with time to live enabled) throughout the month.
Unit Price Per Hour is the ideal method for calculating the monthly billing by aggregating the total hourly write and read capacities provisioned.
Days 1–5 have 120 hours of 100 Write Units, 100 Read Units provisioned. Days 6–15 have 240 hours of 200 Write Units, 200 Read Units provisioned. Days 16–31 have 384 hours of 70 Write Units, 70 Read Units provisioned.
Monthly bill = SUM ((Hourly Write/Read Unit provisioned) x (Write/Read Hourly Unit price)) 
Writes  

Workload period  Hourly write units  Hourly write cost  Total hourly cost for x days  Details 
Day 1–5  100  $0.0169  $2.02  Hourly cost x 120 hours 
Day 6–15  200  $0.0337  $8.09  Hourly cost x 240 hours 
Day 16–31  70  $0.0118  $4.53  Hourly cost x 384 hours 
Monthly billing  $14.64 
Reads  

Workload period  Hourly read units  Hourly read cost  Total hourly cost for x days  Details 
Day 1–5  100  $0.0009  $0.10  Hourly cost x 120 hours 
Day 6–15  200  $0.0017  $0.41  Hourly cost x 240 hours 
Day 16–31  70  $0.0006  $0.23  Hourly cost x 384 hours 
Monthly billing  $0.75 
Storage  

Total storage GB  Monthly billing  Details  
Day 1–31  25  $1.65  25 GB x $0.066 
Total monthly billing $17.04 (Write, read, and storage) 
Note: The total monthly billing number is rounded. There will be some slight differences if you simply total the numbers in the examples using a calculator.
Example 3: Dynamic workloads and multiple provisioned capacities in an hour
This is a special case where different write/read capacities are provisioned within an hour. Assume your application performs two extreme workload changes within an hour. Below is how the cost is calculated when there are more than one write/read unit provisioned within an hour.
Unit Price Per Hour is the ideal method to calculate the monthly billing by aggregating the total hourly write and read capacities provisioned. In this case, the Unit Price Per Hour is also used to calculate the average cost during the hour that has two changes in write and read capacities provisioned.
Days 1–5 have 120 hours of 100 Write Units, 100 Read Units provisioned. Day 6 (12:01 a.m.–12:15 a.m.) has 20 Write Units, 20 Read Units provisioned. Day 6 (12:16 a.m.–1:00 a.m.) has 60 Write Units, 60 Read Units provisioned. Day 6 (1:01 a.m.–11:59 p.m.) have 200 Write Units, 200 Read Units provisioned. Days 7–15 have 216 hours of 200 Write Units, 200 Read Units provisioned. Days 16–31 have 384 hours of 70 Write Units, 70 Read Units provisioned.
Monthly bill = Sum ((Hourly Write/Read Unit provisioned) x (Write/Read Hourly Unit price) + (12:01 a.m.–1:00 a.m. Hourly Average Write/Read Unit provisioned) x (Write/Read Hourly Unit price)) 
Here's a sample of the monthly billing, assuming the storage provisioned on Day One stays constant at 25 GB (with time to live enabled) throughout the month. The average write/read units in Day 6 between 12 a.m.–1 a.m. is as follows:
Writes  

Workload period  Hourly write units  Hourly write cost  Total hourly cost for x days  Details 
Day 1–5  100  $0.0169  $2.02  Hourly cost x 120 hours 
Day 6, 12 a.m.–1 a.m. (Average provisioned capacities)  50  $0.0084  $0.01  Hourly cost x 1 hour 
Day 6, 12:01 a.m.–12:15 a.m. (Write 20 KB/sec)  20  20 writes x 900 seconds  
Day 6, 12:16 a.m.–1:00 a.m. (Write 60 KB/sec)  60  60 writes x 2700 seconds  
Day 6, 1:01 a.m.–12:00 a.m.  200  $0.0337  $0.78  Hourly cost x 23 hours 
Day 7–15  200  $0.0337  $7.28  Hourly cost x 216 hours 
Day 16–31  70  $0.0118  $4.53  Hourly cost x 384 hours 
Monthly billing  $14.62 
Reads  

Workload period  Hourly read units  Hourly read cost  Total hourly cost for x days  Details 
Day 1–5  100  $0.0009  $0.10  Hourly cost x 120 hours 
Day 6, 12 a.m.–1 a.m. (Average provisioned capacities)  50  $0.0004  $0.0004  Hourly cost x 1 hour 
Day 6, 12:01 a.m.–12:15 a.m. (Read 20 KB/sec)  20  20 reads x 900 seconds  
Day 6, 12:16 a.m.–1:00 a.m. (Read 60 KB/sec)  60  60 reads x 2700 seconds  
Day 6, 1:01 a.m.–12:00 a.m.  200  $0.0017  $0.04  Hourly cost x 23 hours 
Day 7–15  200  $0.0017  $0.37  Hourly cost x 216 hours 
Day 16–31  70  $0.0006  $0.23  Hourly cost x 384 hours 
Monthly billing  $0.75 
Storage  

Total storage GB  Monthly billing  Details  
Day 1–31  25  $1.65  25 GB x $0.066 
Total monthly billing $17.01 (Write, read, and storage) 
Note: The total monthly billing number is rounded. There will be some slight differences if you simply total the numbers in the examples using a calculator.
Here is a sample OCI monthly billing statement for December 2022 based on Example 2 above.