INF: Support of Page and Table Locking in SQL Server

ID Number: Q46170

1.00 1.10 1.11 4.20

OS/2

Summary:

SQL Server will lock only the page containing the updated row if an

index was used to locate that row. If an index was not used to locate

the row, by (for example) using the sp_lock() function, the entire

table will be locked.

Using NOT in a WHERE clause or creating an index before data is loaded

and not UPDATING STATISTICS can cause SQL Server to not use indexes.

If a non-clustered index is used to locate a row, the data page will

be locked as well as the leaf-level index page used to locate the row,

even if the value of the indexed column is not changed. If the row was

located via clustered index, only the data page will be locked (unless

the values of indexed columns are changed).

Additional reference words: 1.00 1.10 1.11 4.20