Vfp nolock when updating sql Sex chats send pics of your naked
The sample data creation script below requires a table of numbers.If you do not have one of these already, the script below can be used to create one efficiently.The effect is that everything to the right of the spool is run to completion, storing all the information needed to make changes in a tempdb work table.Once the reading operation is completed, the contents of the work table are replayed to apply the changes at the Clustered Index Update iterator.If this bothers you, feel free to reset the end date column before each run using the following code.The broad points I will be making do not depend on the number of data changes actually made.The Clustered Index Scan is responsible for only a few thousand reads, one per page read.The Spool work table is also structured internally as a b-tree, and counts multiple reads as the spool locates the insert position while consuming its input.
The 'new' cardinality estimator available in SQL Server 2014 onward happens to produce a more accurate estimation for the hash output in this query, so you will not see a hash spill in that case: The number of Actual Rows may be slightly different for you, given the use of a pseudo-random number generator in the script.
I hope this limitation is addressed in a future version of the product.
Another way to express the update query involves numbering the rows per ID and joining: The post-execution plan is as follows: This query typically runs in 2950ms on my laptop, which compares favourably with the 5700ms (in the same circumstances) seen for the original update statement.
As before, the lack of a breakdown makes it impossible to determine which iterator (of the two Scans and the Update) was responsible for the 3 million reads.
Nevertheless, I can tell you that the Clustered Index Scans count only a few thousand logical reads each.