Current Status

This documents reflects ddbmock status as of 3/10/12. It may be outdated.

Methods support

• CreateTable DONE
• DeleteTable DONE
• UpdateTable DONE
• DescribeTable DONE
• GetItem DONE
• PutItem DONE
• DeleteItem DONE
• UpdateItem ALMOST
• BatchGetItem WIP
• BatchWriteItem WIP
• Query WIP
• Scan WIP

There is basically no support for Limit, ExclusiveStartKey, ScanIndexForward and their associated features at all in ddbmock. This affects all “WIP” functions.

UpdateItem has a different behavior when the target item did not exist prior the update operation. In particular, the ADD operator will always behave as though the item existed before.

Comparison Operators

Some comparison might not work as expected on binary data as it is performed on the base64 representation instead of the binary one. Please report a bug if this is a problem for you, or, even better, open a pull request :)

All operators exists as lower case functions in ddbmock.database.comparison. This list can easily be extended to add new/custom operators.

Common to Query and Scan

• EQ DONE
• LE DONE
• LT DONE
• GE DONE
• GT DONE
• BEGINS_WITH DONE
• BETWEEN DONE

Specific to Scan

• NULL DONE
• NOT_NULL DONE
• CONTAINS DONE
• NOT_CONTAINS DONE
• IN DONE

IN operator is the only that can not be imported directly as it overlaps builtin in keyword. If you need it, either import it with getattr on the module or as in_test which, anyway, is its internal name.

Return value specifications

• NONE DONE
• ALL_OLD DONE
• ALL_NEW DONE
• UPDATED_OLD DONE
• UPDATED_NEW DONE

Please note that only UpdateItem supports the 5. Other compatible nethods understands only the 2 first.

Rates and size limitations

basically, none are supported yet

Request rate

• Throttle read operations when provisioned throughput exceeded. TODO
• Throttle write operations when provisioned throughput exceeded. TODO
• Maximum throughput is 10,000. DONE
• Minimum throughput is 1. DONE
• Report accurate throughput. WIP (low level foundations are in place)

ddbmock currently reports the consumed throughput based on item count. Their size is ignored from the computation.

Actually, this is even trickier as the throughput is normally spreaded among partitions which ddbmock does not handle.

Request size

• Limit response size to 1MB. TODO
• Limit request size to 1MB. TODO
• Limit BatchGetItem to 100 per request. TODO
• Linit BatchWriteItem to 25 per request. TODO

Table managment

• No more than 256 tables. DONE
• No more than 10 CREATING tables. TODO
• No more than 10 DELETING tables. TODO
• No more than 1 UPDATING table. TODO
• No more than 1 Throughput decrease/calendar day. DONE
• No more than *2 Throughput increase/update. DONE
• At least 10% change per update. DONE

Types and items Limitations

• Table names can only be between 3 and 255 bytes long. DONE
• Table names can only contains a-z, A-Z, 0-9, ‘_’, ‘-‘, and ‘.’. DONE
• No more than 64kB/Item including fieldname but not indexing overhead. DONE
• Primary key names can only be between 1 and 255 bytes long. DONE
• Attribute value can not be Null. DONE
• hash_key value maximu 2048 bytes. DONE
• range_key value maximu 1024 bytes. DONE
• Numbers max 38 digits precision; between 10^-128 and 10^+126. DONE

Table description

• item count. DONE
• data size. DONE
• date: creation. DONE
• date: last throughput increase. DONE
• date: last throughput decrease. DONE

Dates are represented as float timestamps using scientific notation by DynamoDB but we only send them as plain number, not caring about the representation. Most parsers won’t do any difference anyway.