Jump to the Code block for a combined complete example.
A client application can also issue an asynchronous background query to the database and apply a series of write transaction operations to each record. This is more efficient than a query to retrieve records followed by updates to them for cases where data needs to be manipulated on the client side. Transactional operations are typically more efficient than using Lua UDFs because the server doesn't need to translate internal objects to another language. Many client libraries also provide an API to poll for the completion of a background query.
Refer to Background Queries for more information.
The following examples will use the setup and record structure below to illustrate batch operations in an Aerospike database.
The record structure:
Background queries can define policies to pass to the executed task.
The following example creates a policy that defines a filter expression looking for records that do not already
Just like basic queries background queries can be run on the primary index or, using a filter, on a secondary index.
The following example creates a primary index background query using the Filter Expression defined in the policies example to find all
records without a
numShapes bin, then get the length of the
shape key in the
report map and write that value to a new bin called
The following example uses a secondary index created on the
asadm -e 'enable; manage sindex create numeric occurred_idx ns sandbox set ufodata bin occurred'
Then creates a secondary index background query using a Filter Expression checking for the existence of a
posted bin on records
that have an
occurred bin value inclusively between
20211231, that updates the
report map by adding a
key with a value of
Once a background query has been executed, a query status can be obtained to query nodes for task completion.