Limits
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 | 20 |
Maximum number of comparisons per Select expression | 20 |
Maximum response size for Select | 1MB |
