Database Reference
In-Depth Information
Watching for expanding item collections
While creating a DynamoDB table, there are no restrictions. But once it has been created,
there are a few limitations. One such limitation is on the hash key limit. We already know
that table items will be partitioned on the hash key value. What we don't know is that it is
not possible for the same hash key value (of the table and index collectively) to have items
greater than 10 GB.
For example, in our
Tbl_Book
function, we have a hash key attribute named
BookTitle
. Let's say that we inserted items with
BookTitle
as SCJP and after a point
of time, we stored items with a collective size of 6 GB with SCJP as the hash key. If we
create an index with
BookTitle
as the hash key (and assume that 4 GB space is con-
sumed by the SCJP hash key in the index), we cannot insert even a single item into this
table. So if a large number of items need to be inserted for certain hash key attributes, then
we are not supposed to create any secondary indexes with the same hash key, which will
restrict the size of the table. Beyond 10 GB, DynamoDB will start returning
ItemCol-
lectionSizeLimitExceededException
.
