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Posted by Erland Sommarskog on 03/30/06 00:45
(zelnaga@gmail.com) writes:
> according to the mysql manual, multiple inserts can be sped up by
> locking the table before doing them and unlocking the table afterwards.
>
> is the same true of multiple inserts in mysql? if so, how would the
> table be locked?
>
> any insights would be appreciated - thanks!
In case "mysql" in the second paragraph is a type for MS SQL Server, the
answer is that you cannot really lock a table as such in MS SQL Server,
and definitely not unlock it. You can specify a locking hint to get a
table lock when you insert the first row. Note that you need to have a
user-defined transaction in progress, or else the lock will be released
since statements auto-commit in SQL Server. To "unlock" you simply commit
the transaction.
However, normally you don't play these games for insert statments. It's
better to let SQL Srever choose the locking mode.
If you need to load lots of data, you use BCP (a command-line tool) or
BULK INSERT (an SQL Statement). With these you can specify table lock to
speed up the operation.
--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se
Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx
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