Paginate results in Amazon Keyspaces - Amazon Keyspaces (for Apache Cassandra)

Paginate results in Amazon Keyspaces

Amazon Keyspaces automatically paginates the results from SELECT statements when the data read to process the SELECT statement exceeds 1 MB. With pagination, the SELECT statement results are divided into "pages" of data that are 1 MB in size (or less). An application can process the first page of results, then the second page, and so on. Clients should always check for pagination tokens when processing SELECT queries that return multiple rows.

If a client supplies a PAGE SIZE that requires reading more than 1 MB of data, Amazon Keyspaces breaks up the results automatically into multiple pages based on the 1 MB data-read increments.

For example, if the average size of a row is 100 KB and you specify a PAGE SIZE of 20, Amazon Keyspaces paginates data automatically after it reads 10 rows (1000 KB of data read).

Because Amazon Keyspaces paginates results based on the number of rows that it reads to process a request and not the number of rows returned in the result set, some pages may not contain any rows if you are running filtered queries.

For example, if you set PAGE SIZE to 10 and Keyspaces evaluates 30 rows to process your SELECT query, Amazon Keyspaces will return three pages. If only a subset of the rows matched your query, some pages may have less than 10 rows. For an example how the PAGE SIZE of LIMIT queries can affect read capacity, see Estimate the read capacity consumption of limit queries.

For a comparison with Apache Cassandra pagination, see Pagination.