Index locking

Index locking is a procedure in which running one task on a database table blocks all access by other tasks to the entire table. With index locking it may be necessary to lock the index build for a column, not just the data items themselves. Index locking prevents conflicts between functions by ensuring that a table is not modified while a function is attempting to use it.

The circumstances where it is necessary to index lock include:

• Adding a new level to the root page
• Shrinking the root page
• Splitting or shrinking the immediate child of the root page, causing an update on the root page

Circumstances where it is not necessary to Index lock include where:

• Small tables with index levels no higher than 3 are being used.
• Possible modifications to the root page of an index are envisioned.