How Does Bulk Insert Work Internally

How does BULK INSERT work internally?

BULK INSERT runs in-process with the database engine of SQL Server and thus avoids passing data through the network layer of the Client API - this makes it faster than BCP and DTS / SSIS.

Also, with BULK INSERT, you can specify the ORDER BY of the data, and if this is the same as the PK of the table, then the locking occurs at a PAGE level. Writes to the transaction logs happen at a page level rather than a row level as well.

In the case of regular INSERT, the locking and the Transaction log writes are at a row level. That makes BULK INSERT faster than an INSERT statement.

Cassandra bulk insert operation, internally

Correct, this is not supported natively. (Another alternative would be a map/reduce job.) Cassandra's API focuses on short requests for applications at scale, not batch or analytical queries.

How to do bulk (multi row) inserts with JpaRepository?

To get a bulk insert with Spring Boot and Spring Data JPA you need only two things:

1. set the option spring.jpa.properties.hibernate.jdbc.batch_size to appropriate value you need (for example: 20).

2. use saveAll() method of your repo with the list of entities prepared for inserting.

Working example is here.

Regarding the transformation of the insert statement into something like this:

INSERT INTO table VALUES (1, 2), (3, 4), (5, 6)

the such is available in PostgreSQL: you can set the option reWriteBatchedInserts to true in jdbc connection string:

jdbc:postgresql://localhost:5432/db?reWriteBatchedInserts=true

then jdbc driver will do this transformation.

Additional info about batching you can find here.

UPDATED

Demo project in Kotlin: sb-kotlin-batch-insert-demo

UPDATED

Hibernate disables insert batching at the JDBC level transparently if you use an IDENTITY identifier generator.

Bulk Insert/Load in MySQL and HBase

As far as i know, this depends on the Hbase configuration also. Normally a bulk insert would mean usage of List of Puts together, in this case, the insert ( called flushing in habse layer) is done automatically when you call table.put. Single inserts might wait for any other insert call so as to do a batch flush in the middle layer. However this will depend on the configuration also.

Another reason may be the easiness of task, its more efficient Map and Reduce, if you have more jobs at a time. The migration of file chunks are decided for all inputs single time. But in indvidual inserts, this becomes a crucial point.

Is there a way for bulk insert or update of records using Hibernate

this here!
This will work for your Scenario.

Which is faster: multiple single INSERTs or one multiple-row INSERT?

https://dev.mysql.com/doc/refman/8.0/en/insert-optimization.html

The time required for inserting a row is determined by the following factors, where the numbers indicate approximate proportions:

• Connecting: (3)
• Sending query to server: (2)
• Parsing query: (2)
• Inserting row: (1 × size of row)
• Inserting indexes: (1 × number of indexes)
• Closing: (1)

From this it should be obvious, that sending one large statement will save you an overhead of 7 per insert statement, which in further reading the text also says:

If you are inserting many rows from the same client at the same time, use INSERT statements with multiple VALUES lists to insert several rows at a time. This is considerably faster (many times faster in some cases) than using separate single-row INSERT statements.

Need Help: Create Stored Procedure for Bulk Insert

The SQL to execute an SP LoadDailyAdjReport would be EXEC LoadDailyAdjReport - so try this in ypur batch file SQLCMD :

sqlcmd -S YourServerName -E -d YourDataBaseName -Q "EXEC LoadDailyAdjReport"

(-E uses trusted connection (Windows login) more details here

http://msdn.microsoft.com/en-us/library/ms162773.aspx )

If you want to dabble with passing in the .txt filename as a parameter, see

How do I call a stored procedure with arguments using sqlcmd.exe?

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