Data-only Locking

Sybase now supports new locking methods called “data-only” locking. In previous releases, all locking happened at the page level. When you upgrade, by default, your server performs page-level locking. However, you may change the locking scheme on your existing tables with the alter table command.

The new locking schemes are:

If you intend to use the data-only locking feature, you need to be aware of the following system and application issues:

Clustered indexes on data-only-locked tables may not return rows in clustered key order if there is no order by clause. Bulk copy is not guaranteed to copy out a table in clustered key order.

Queries on unpartitioned allpages-locked tables with clustered indexes return rows in the clustered key order if the query does not include a sort (that is, if there are no clauses such as order by or distinct). Bulk copy also copies the rows out of allpages-locked tables in clustered key order for both partitioned and unpartitioned tables.