DataStax Astra Developer Hub

Welcome to the DataStax Astra Developer Hub. You'll find comprehensive guides and documentation to help you start working with DataStax Astra as quickly as possible. Use the included APIs to create, modify, and terminate databases, and interact with the databases you create. Let's do it!

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DataStax Astra database limits

DataStax Astra sets limits for databases to ensure good practices, foster availability, and promote optimal configurations for your database.

DataStax Astra offers a Free tier, allowing you to create an Astra database with 5 GB for free. Create a databasedatabase - A group of distributed instances for storing data. Each paid Astra database has at least three instances. with just a few clicks and start developing within minutes.

You can create up to 5 databases per regionregion - A group of related nodes configured together within a database for replication purposes. A region is virtual datacenter hosted on your selected cloud provider. Using separate regions prevents transactions from being impacted by other workloads and lowers latency. Depending on the replication factor, data can be written to multiple regions. Regions cannot span physical locations. A region in Astra is the same concept as a "datacenter" in Apache Cassandra™ or DataStax Enterprise., and add a total of 20 capacity units (CUs) per database (10TBs). To adjust the capacity unitcapacity unit - Represents three database instances grouped together with three replicas. limits, contact DataStax Support.

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Note

Astra provides one database on the Free tier per user.

The following limits are set for all databases not on the Free tier created using DataStax Astra. These limits ensure good practices, foster availability, and promote optimal configurations for your database.

Columns

Parameter

Limit

Notes

Size of values in a single columncolumn - The smallest increment of data, which contains a name, a value, and a timestamp. Also known as a cell.

5 MB

Hard limit.

Number of columns per tabletable - Stores data based on a primary key, which consists of a partition key and optional clustering columns. A partition key defines the node on which the data is stored, and divides data into logical groups. Define partition keys that evenly distribute the data and also satisfy specific queries. Query and write requests across multiple partitions should be avoided if possible. A clustering column defines the sort order of rows within a partition. When defining a clustering column, consider the purpose of the data. For example, retrieving the most recent transactions, sorted by date, in descending order.

50

Hard limit.

Tables

Parameter

Limit

Notes

Number of tables per keyspacekeyspace - The defining container for replication, similar to a schema in a relational database. All tables belong to a keyspace. Each keyspace can contain as many as 200 tables.

200

A warning is issued when the database exceeds 100 tables.

Table properties

Fixed

All table properties are fixed except for Expiring data with time-to-live.

Secondary indexindex - A native capability for finding a column in the database that does not involve using the primary key.

1

Limit is per table.

Materialized view

2

Limit is per table. A warning is issued if the materialized view will create large partitions.

Cassandra Query Language (CQL)

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Note

At this time, user-defined functions (UDFs) and user-defined aggregate functions (UDAs) are not enabled.

Parameter

Limit

Notes

Consistency level

Fixed

Supported consistency levels:

Compaction strategy

Fixed

Only the SizeTieredCompaction strategy is supported.

Lists

Fixed

Cannot UPDATE, INSERT, or DELETE a list value by index because Astra does not allow list operations which perform a read-before-write.

Page size

Fixed

The proper page size is configured automatically.

Large partition

Warning

A warning is issued if reading or compacting a partition that exceeds 50 MB.

cassandra.yaml

If you are an experienced Cassandra or DataStax Enterprise, you are likely familiar with editing the cassandra.yaml file. For Astra, the cassandra.yaml file cannot be configured. The following limits are included in Astra:

// for read requests
        page_size_failure_threshold_in_kb =  512
        in_select_cartesian_product_failure_threshold =  25
        partition_keys_in_select_failure_threshold = 20
        tombstone_warn_threshold = 1000
        tombstone_failure_threshold = 100000

// for write requests
        batch_size_warn_threshold_in_kb = 5
        batch_size_fail_threshold_in_kb = 50
        unlogged_batch_across_partitions_warn_threshold = 10
        user_timestamps_enabled = true
        column_value_size_failure_threshold_in_kb = 5 * 1024L
        read_before_write_list_operations_enabled = false

// for schema
        fields_per_udt_failure_threshold = 10
        collection_size_warn_threshold_in_kb =  5 * 1024L
        items_per_collection_warn_threshold =  20
        columns_per_table_failure_threshold = 50
        secondary_index_per_table_failure_threshold = 1
        materialized_view_per_table_failure_threshold = 2
        tables_warn_threshold = 100
        tables_failure_threshold = 200
    
// for node status
        disk_usage_percentage_warn_threshold =  70
        disk_usage_percentage_failure_threshold =  80
        partition_size_warn_threshold_in_mb =  100

// SAI Table Failure threshold 
        sai_indexes_per_table_failure_threshold = 10

Updated 4 days ago


DataStax Astra database limits


DataStax Astra sets limits for databases to ensure good practices, foster availability, and promote optimal configurations for your database.

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