Before you change from allpages locking to data-only locking or vice versa, the following steps are recommended:
If the table is partitioned, and update statistics has not been run since major data modifications to the table, run update statistics on the table that you plan to alter. alter table...lock performs better with accurate statistics for partitioned tables.
Changing the locking scheme does not affect the distribution of data on partitions; rows in partition 1 are copied to partition 1 in the copy of the table.
Perform a database dump.
Set any space management properties that should be applied to the copy of the table or its rebuilt indexes.
See Chapter 9, “Setting Space Management Properties,” in the Performance and Tuning: General Information for more information.
Determine if there is enough space.
See “Determining the space available for maintenance activities” on page 356 in the Performance and Tuning: General Information.
If any of the tables in the database are partitioned and require a parallel sort:
Use sp_dboption to set the database option select into/bulkcopy/pllsort to true and run checkpoint in the database.
Set your configuration for optimum parallel sort performance.
