Amazon SimpleDB
Developer Guide (API Version 2009-04-15)


Following is a table that describes current limits within Amazon SimpleDB.

Parameter Restriction
Domain size 10 GB per domain
Domain size 1 billion attributes per domain
Domain name 3-255 characters (a-z, A-Z, 0-9, '_', '-', and '.')
Domains per account 250
Attribute name-value pairs per item 256
Attribute name length 1024 bytes
Attribute value length 1024 bytes
Item name length 1024 bytes
Attribute name, attribute value, and item name allowed characters

All UTF-8 characters that are valid in XML documents.

Control characters and any sequences that are not valid in XML are returned Base64-encoded. For more information, see Working with XML-Restricted Characters.

Attributes per PutAttributes operation 256
Attributes requested per Select operation 256
Items per BatchDeleteAttributes operation 25
Items per BatchPutAttributes operation 25
Maximum items in Select response 2500
Maximum query execution time 5 seconds
Maximum number of unique attributes per Select expression


Maximum number of comparisons per Select expression


Maximum response size for Select 1MB