Delete by Query Operation
DeleteByQueryOperation
gives you the ability to delete a large number of documents with a single query.
This operation is performed in the background on the server.
Syntax
public DeleteByQueryOperation(IndexQuery queryToDelete)
public DeleteByQueryOperation(IndexQuery queryToDelete, QueryOperationOptions options)
Parameters | Type | Description |
---|---|---|
indexName | String | Name of an index to perform a query on |
queryToDelete | IndexQuery | Holds all the information required to query an index |
options | QueryOperationOptions | Holds different setting options for base operations |
Example I
// remove all documents from the server where Name == Bob using Person/ByName index
store
.operations()
.send(new DeleteByQueryOperation(new IndexQuery("from Persons where name = 'Bob'")));
from index 'Person/ByName' where Name = 'Bob'
Example II
// remove all documents from the server where Age > 35 using Person/ByAge index
store
.operations()
.send(new DeleteByQueryOperation(new IndexQuery("from 'Person/ByAge' where age < 35")));
from index 'Person/ByName' where Age < 35
Example III
// delete multiple docs with specific ids in a single run without loading them into the session
Operation operation = store
.operations()
.sendAsync(new DeleteByQueryOperation(new IndexQuery(
"from People u where id(u) in ('people/1-A', 'people/3-A')"
)));
from People u where id(u) in ('people/1-A', 'people/3-A')
WaitForCompletion
DeleteByQueryOperation
is performed in the background on the server.
You have the option to wait for it using waitForCompletion
.
// remove all document from server where Name == Bob and Age >= 29 using People collection
Operation operation = store.operations()
.sendAsync(new DeleteByQueryOperation(new IndexQuery(
"from People where Name = 'Bob' and Age >= 29"
)));
operation.waitForCompletion();
from People where Name = 'Bob' and Age >= 29
Remarks
Map only indexes
DeleteByQueryOperation
can only be performed on a map index. Executing it on map-reduce index will lead to an exception.
Batching and Concurrency
The deletion of documents matching a specified query is run in batches of size 1024. RavenDB doesn't do concurrency checks during the operation so it can happen than a document has been updated or deleted meanwhile.