MySQL与MS SQL Server —进行插入/更新的并行进程

Question

I'm using a 3rd party ETL application (Pentaho/ Kettle/ Spoon) --- so unfortunately I'm not sure of the exact SQL query, but I can try different manual queries.

I'm just wondering why ... MySQL seems to allow multiple processes at once do an insert, but if found, update ... queries.

MS SQL does not ... it "locks" the rows when one query is doing an insert/ update ... and throws an error if another query tries to insert/ update over the same data.

I guess this makes sense ... but I'm just a bit annoyed that MySQL allows this, and MS SQL does not.

Is there any way to get around this?

I just want as fast a way as possible to insert/ update a list of 1000 records into a data table. In the past I just divided this numbers into 20 processes updating 50 records doing insert/ updates ... this worked in parallel because none of the 1000 records are duplicate ... they are only some duplicates of them already in table ... so they can be inserted/ updated in any order, so long as it happens.

Any thoughts? Thanks

Answer 1

MySQL use the ISAM storage engine by default which does not support transactions. SQL Server is a RDBMS and supports transactions as you've observed though you can tweak the isolation levels to do risky things like read uncommitted (very rarely a good idea).

If you want your MySQL database to have transaction support, you need to explicitly create your table with the option ENGINE=INNODB. Older versions also support ENGINE=BDB which is the Berkeley Database engine. See MySQL docs for more details on InnoDB http://dev.mysql.com/doc/refman/5.7/en/innodb-storage-engine.html