Speeding Inserts of longtext or longblob columns
InnoDB Architecture (from Percona CTO Vadim Tkachenko)




  
  What are the values recommended for the batch insert size, considering the size of the columns (longtext, longblob)?
  



Increase innodb_log_buffer_size to 256M
Increase innodb_log_file_size to 2G
I wrote about increasing these to accommodate TEXT/BLOB fields in the past


Apr 20, 2011 : MySQL gives &quot;Out of Memory&quot; error when inserting a large file. From where is this filesize limitation arising?
Apr 27, 2011 : Changed max_allowed_packet and still receiving &#39;Packet Too Large&#39; error 
Aug 01, 2011 : How does max_allowed_packet affect the  backup and restore of a database?




  
  Is there any tuning recommended on my.cnf to improve the insert performance?
  



Increase the Write I/O Threads (For more info, see Configuring the Number of Background InnoDB I/O Threads)
Change innodb_thread_concurrency to default setting of 0


Proposed Changes

[mysqld]
innodb_log_buffer_size    = 256M
innodb_log_file_size      = 2G
innodb_write_io_threads   = 16
innodb_thread_concurrency = 0


GIVE IT A TRY !!!