The tradeoff is that you’re locking more rows for a longer period of time with a larger TOP value.
Sql server updating large databases adiult dating upgrade
Additional execution time can be saved by using SELECT INTO (recovery model was simple), which is minimally- logged.
You cannot specify a file group when using SELECT INTO, so to retain the split I\O performance you must set the target file group as the default before running the insert. Results are summarized in the table below: Statement Runtime (H: M) % Runtime Reduction Update na Insert 86.8 Select Into 91.5 See the following for more information regarding recovery models and minimally-logged operations: BOL: ms-help://MS. SQLSVR.v9.en/udb9/html/8cfea566-8f89-4581-b30d-c53f1f2c79MSDN: exercise provided an example of how certain operations can be non-optimal even with a great database like SQL Server.
Here are few tips to SQL Server Optimizing the updates on large data volumes. Let’s look at the execution plan of the query shown below.
In addition to the clustered index update, the index ix_col1 is also updated.
You declare a local table to hold the primary key values of the table being updated, then use the OUTPUT clause to capture the primary key values for the rows that are updated. For the WHILE loop to start, the @@ROWCOUNT function must return a value greater than 0.