The WriteRecords operation enables you to write your time series data into Timestream. You can specify a single data point or a batch of data points to be inserted into the system. Timestream offers you with a flexible schema that auto detects the column names and data types for your Timestream tables based on the dimension names and data types of the data points you specify when invoking writes into the database. Timestream support eventual consistency read semantics. This means that when you query data immediately after writing a batch of data into Timestream, the query results might not reflect the results of a recently completed write operation. The results may also include some stale data. If you repeat the query request after a short time, the results should return the latest data. Service quotas apply.

See code sample for details.

Upserts

You can use the Version parameter in a WriteRecords request to update data points. Timestream tracks a version number with each record. Version defaults to 1 when not specified for the record in the request. Timestream will update an existing record’s measure value along with its Version upon receiving a write request with a higher Version number for that record. Upon receiving an update request where the measure value is the same as that of the existing record, Timestream still updates Version, if it is greater than the existing value of Version. You can update a data point as many times as desired, as long as the value of Version continuously increases.

For example, suppose you write a new record without indicating Version in the request. Timestream will store this record, and set Version to 1. Now, suppose you try to update this record with a WriteRecords request of the same record with a different measure value but, like before, do not provide Version. In this case, Timestream will reject this update with a RejectedRecordsException since the updated record’s version is not greater than the existing value of Version. However, if you were to resend the update request with Version set to 2, Timestream would then succeed in updating the record’s value, and the Version would be set to 2. Next, suppose you sent a WriteRecords request with this same record and an identical measure value, but with Version set to 3. In this case, Timestream would only update Version to 3. Any further updates would need to send a version number greater than 3, or the update requests would receive a RejectedRecordsException.