(mysql.info) concurrent-inserts
Info Catalog
(mysql.info) table-locking
(mysql.info) locking-issues
7.3.3 Concurrent Inserts
------------------------
For a `MyISAM' table, you can use concurrent inserts to add rows at the
same time that `SELECT' statements are running if there are no deleted
rows in middle of the table.
Under circumstances where concurrent inserts can be used, there is
seldom any need to use the `DELAYED' modifier for `INSERT' statements.
See insert-delayed.
If you are using the binary log, concurrent inserts are converted to
normal inserts for `CREATE ... SELECT' or `INSERT ... SELECT'
statements. This is done to ensure that you can re-create an exact copy
of your tables by applying the log during a backup operation.
With `LOAD DATA INFILE', if you specify `CONCURRENT' with a `MyISAM'
table that satisfies the condition for concurrent inserts (that is, it
contains no free blocks in the middle), other threads can retrieve data
from the table while `LOAD DATA' is executing. Using this option
affects the performance of `LOAD DATA' a bit, even if no other thread is
using the table at the same time.
Info Catalog
(mysql.info) table-locking
(mysql.info) locking-issues
automatically generated byinfo2html