kenneth d'souza wrote: > <DIV>Let us imagine if there is Process P which is holding a lock and > there are individual waiters p1 p2 p3 p4 p5 p6 requiring the same > lock. Now since they are in conflict it is sure that there will be > wait queue that will get generated as in p1 p2 p3 p4 p5 p6. > <BR>Imagine if Process P releases it lock. As per explaination given > in (a) it is sure that p1 will wake up. What is the status of p2. It > was in conflict with process P and hence should we term it that it > will not wake up. Same is the case with p2 ... p6. </DIV>
If p2's requested lock does not conflict with p1's granted lock, then it will be awakened also (for example if P had an AccessExclusive lock and both p1 and p2 were requesting an AccessShare lock). > <DIV>Secondly if p2 is not woken up and if p3's lock doesn't conflict > with ( P and p2 ) then by rule(b) will p3 move ahead of > p2</DIV> No, sleeping waiters are not moved ahead. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
