Commands that use large amounts of space allocate new space by allocating an extent rather than allocating single pages. The reservepagegap keyword causes these commands to leave empty pages so that subsequent page allocations occur close to the page being split or close to the page from which a row is being forwarded.
This table shows when reservepagegap is applied:
|
Command |
Applies to data pages |
Applies to index pages |
|---|---|---|
|
Fast bcp |
Yes |
Fast bcp is not used if indexes exist |
|
Slow bcp |
Only for heap tables, not for tables with a clustered index |
Extent allocation not performed |
|
select into |
Yes |
No indexes exist on the target table |
|
create index or alter table...constraint |
Yes, for clustered indexes |
Yes |
|
reorg rebuild |
Yes |
Yes |
|
alter table...lock (For allpages-locking to data-only locking, or vice versa) |
Yes |
Yes |