Bulk Insert
Definition
INSERT all entities in the database.
All entities are considered as new rows and are INSERTED in the database.
// Easy to use
context.BulkInsert(list);
// Easy to customize
context.BulkInsert(list, options => options.BatchSize = 100);
Purpose
Inserting thousand of entities for an initial load or a file importation is a typical scenario.
BulkInsert in counterpart requires the minimum database round-trips as possible. By example under the hood for SQL Server, a simpleSqlBulkCopy could be performed.
Performance Comparisons
| Operations | 1,000 Entities | 2,000 Entities | 5,000 Entities |
|---|---|---|---|
| SubmitChanges | 1,000 ms | 2,000 ms | 5,000 ms |
| BulkInsert | 6 ms | 10 ms | 15 ms |
How can I specify more than one option?
You can specify more than one option using anonymous block.
context.BulkInsert(list, options => {
options.BatchSize = 100);
options.ColumnInputExpression = c => new {c.Name, c.Description});
});
How can I specify the Batch Size?
You can specify a custom batch size using the BatchSize option.
Read more: BatchSize
context.BulkInsert(list, options => options.BatchSize = 100);
How can I specify custom columns to Insert?
You can specify custom columns using the ColumnInputExpression option.
Read more: ColumnInputExpression
context.BulkInsert(list, options => options.ColumnInputExpression = c => new {c.Name, c.Description});
Why BulkInsert doesn't use the ChangeTracker?
To provide the best performance possible!
Since using the ChangeTracker can greatly reduce performance, we chose to let SubmitChanges method handle the scenarios with ChangeTracker and BulkInsert the scenarios without it.
Why BulkInsert is faster than SubmitChanges?
The major difference between both methods is SubmitChanges uses the ChangeTracker but not the BulkInsert method.
By skipping the ChangeTracker, some methods like Add, AddRange, DetectChanges are no longer required which greatly helps to improve the performance.