Batch update mysql how to#
Batch update mysql update#
Batch update mysql driver#

The reason why temporary table is used is because ofĪ) speed, a temporary table is usually created in the memory and will be converted to use disk storage if the temporary table becomes too large (hence data loss is prevented)ī) convenience, when the db link is disconnected,temporary tables are dropped automatically

Batch update mysql update#

Please note this table doesn’t have to have exactly the same data structure as tbl_A, as long as it holds the columns that will be used in step 5 and it’s also a good idea to remove any indexes to speed up insertion (to the temporary table).Ģ) Use delete or truncate statement to delete any existing rows in tbl_A_tmpģ) Inside the loop, save new records to an array list_new and existing records to an array list_existing, when num_of_elements(list_new) >=BATCHCOUNT, do batch insertion to tbl_A directly, when num_of_elements(list_existing) >=BATCHCOUNT, do batch insertion to tbl_A_tmp, clear list_new or list_existing after each batch insertionĤ) When looping is done, Check remaining number of elements in both list_new and list_existing, perform batch insertions for any remaining records to the corresponding tablesĤ) Add unique or primary key to tbl_A_tmp, without this the next step will be very slowĥ) Perform cross-table update like the following Let’s assume the table we are going to insert/update has the following structure:ġ) Before entering the loop, create a temporary table tbl_A_tmpĬreate temporary table if not exists tbl_A_tmp ( Through a project I completed recently, I’ve learned a new way to solve the above problem, and the basic idea is to use bulk insertion to accomplish the goal of bulk updates, with the help of mysql temporary table. Prepare/Execute method might help a bit but still the performance is not satisfactory. Updating existing rows is quite a different story as there’s not yet an official way to do “bulk” updating.

For new records, using bulk insertion is pretty easy. The external source has a column that will be checked against the table’s primary key to determine if a record is new or not. This way, the number of inserts per batch will be the minimum between the batch insert size defined in VDP and the value of the property ‘ max_allowed_packet ’ defined in MySQL.Ĭonfiguring MySQL data sources to enable batch insertions is recommended as it will improve the performance when acting as a VDP cache or as a data movement target source.You need to insert or update a large number of rows (at least hundreds of thousands) from an external data source (either from other database or file) into an existing mysql table but you are not allowed to truncate the table first because data source contains less number of columns than the existing table. It is important to notice that this limit is more restrictive than the Batch size configured in Virtual DataPort for the data source. This parameter is defined on the MySQL server side.

The property ‘ max_allowed_packet ’ defines the maximum size of a single network packet, so this parameter will limit the number of inserts included in a batch. There is also another important thing to take into account when dealing with batch inserts on MySQL. INSERT INTO jdbc (`name`) VALUES ('value_name_1'),('value_name_2') Once this property is set to true, the rows will effectively be inserted in batches: To the connection URL in the configuration of the data source or cache. In order to do this, it is just needed to add the property

Batch update mysql driver#

To take advantage of batch inserts when using MySQL is necessary to change how the MySQL jdbc driver performs the connection. INSERT INTO jdbc ( `name` ) VALUES ( 'value_name_2' )

INSERT INTO jdbc ( `name` ) VALUES ( 'value_name_1' ) This implies that Virtual DataPort’s cache batch inserts are not going to be effective and all the rows are going to be inserted one at a time: When using a MySQL database as a cache database or as a data movement target source, it is important to notice that, by default, MySQL does not allow Batched statements.

To speed up the data movement, the INSERT statements are also executed in batches. In the same way, when a data source is the target of a Data Movement operation, the Virtual DataPort server inserts data obtained from another data source into the target data source. The size of the batches is determined by the ‘ batch insert size ’ parameter in the cache configuration. When the cache for a Virtual DataPort view is being populated, the rows obtained from the source are stored in the cache database using batch insertions.

Batch update mysql how to#

This document explains the behavior of the default configuration in MySQL databases for batch inserts and how to configure MySQL properly to take advantage of batch inserts when used as cache or as a data movement enabled data source in Virtual DataPort.