Any practical examples of share, row share, row excl, share row excl ?
From: Aniruddha Kortikar <kortikar_at_mipos2.intel.com>
Date: 11 Aug 92 15:57:12 GMT
Message-ID: <12884_at_inews.intel.com>
Date: 11 Aug 92 15:57:12 GMT
Message-ID: <12884_at_inews.intel.com>
Hi there
would anyone have practical examples of above mentioned locks ? I have created following matrix
User A User B Status locks in Locks in 1. share mode select for update succeeds update where ... fails 2. share row excl select for update succeeds update where ... fails 3. row share select for update succeeds update where succeeds 4. row exclusive select for update succeeds update where succeeds 5. update where .. row share succeeds 6. update where row excl succeeds 7. update where share mode fails 8. update where share row excl fails
could anybody tell how these locks differ from each other. and PRACTICAL examples of usage of these categories. I have read pages of chapter 12. but rather than "RX lock prevents another RX or S lock" type of language I would like itif somebody gave me real world exmamples of using these locking modes. If anybody has used "lock table in share mode" or "lock tables in share row excl" will he /she please respond.