CREATE TABLE [IF NOT EXISTS] tablename attributes [GLOBAL [ALL|KEYS|INCLUDE] INDEX global_index]
CREATE TABLE foobars (id STRING HASH KEY); CREATE TABLE IF NOT EXISTS foobars (id STRING HASH KEY); CREATE TABLE foobars (id STRING HASH KEY, foo BINARY RANGE KEY, THROUGHPUT (1, 1)); CREATE TABLE foobars (id STRING HASH KEY, foo BINARY RANGE KEY, ts NUMBER INDEX('ts-index'), views NUMBER INDEX('views-index')); CREATE TABLE foobars (id STRING HASH KEY, bar STRING) GLOBAL INDEX ('bar-index', bar, THROUGHPUT (1, 1)); CREATE TABLE foobars (id STRING HASH KEY, baz NUMBER, THROUGHPUT (2, 2)) GLOBAL INDEX ('bar-index', bar STRING, baz) GLOBAL INCLUDE INDEX ('baz-index', baz, ['bar'], THROUGHPUT (4, 2));
Create a new table. You must have exactly one hash key, zero or one range keys, and up to five local indexes and five global indexes. You must have a range key in order to have any local indexes.
- IF NOT EXISTS
- If present, do not through an exception if the table already exists.
- The name of the table that you want to alter
- A list of attribute declarations of the format (name data type [key
type]) The available data types are
BINARY. You will not need to specify any other type, because these fields are only used for index creation and it is (presently) impossible to index anything other than these three. The available key types are
RANGE KEY, and
[ALL|KEYS|INCLUDE] INDEX(name). At the end of the attribute list you may specify the
THROUGHPUT, which is in the form of
(read_throughput, write_throughput). If throughput is not specified it will default to
- A global index for the table. You may provide up to 5. The format is
(name, hash key, [range key], [non-key attributes], [throughput]).
If the hash/range key is in the attributes declaration, you don’t need
to supply a data type.. non-key attributes should only be provided if it
INCLUDEindex. If throughput is not specified it will default to
Schema Design at a Glance¶
When DynamoDB scales, it partitions based on the hash key. For this reason, all queries (not scans) must include the hash key in the WHERE clause (and optionally the range key or a local/global index). So keep that in mind as you design your schema.
The keypair formed by the hash key and range key is referred to as the ‘primary key’. If there is no range key, the primary key is just the hash key. The primary key is unique among items in the table. No two items may have the same primary key.
From a query standpoint, local indexes behave nearly the same as a range key. The main difference is that the hash key + range key pair doesn’t have to be unique.
Global indexes can be thought of as adding additional hash and range keys to the table. They allow you to query a table on a different hash key than the one defined on the table. Global indexes have throughput that is managed independently of the table they are on. Global index keys do not have a uniqueness constraint (there may be multiple items in the table that have the same hash and range key).
Read Amazon’s documentation for Create Table for more information.