lock

New Features 23c, Overview (in extracts):

In this blog I want to introduce some of the new features of the Oracle 23c developer edition. It will be only a selection of some of the main features. It is not the intention to give you a(…)

Oracle Lock Free Reservations

The Oracle 23c new feature Lock Free Reservations allows to break with the traditional locking mechanism. Now multiple concurrent sessions can update the same row without be blocked !!! Let’s see how it works. In the(…)

A few words about the good to know MAX_IDLE_BLOCKER_TIME

The increasing popularity of tools like SQL Developer and Toad, sometimes comes hand in hand with an increase of stuck sessions.This is especially seen in cases where: User A does a change (neither committed nor rolled back). Then, switches(…)

Documentum Upgrade – Castor is locked!

One of the best practices while doing upgrade of Documentum is to unlock the various repository objects before starting. This will make sure that if the upgrade process requires an update of some objects, then it will succeed and not(…)

Documentum story – How to avoid “DFC_FILE_LOCK_ACQUIRE_WARN” messages in Java Method Server (jms) LOG

After upgrading from 6.7.x to 7.2, the following warning message is logged in JMS log files: com.documentum.fc.common.DfNewInterprocessLockImpl – [DFC_FILE_LOCK_ACQUIRE_WARN] Failed to acquire lock proceeding ahead with no lock java.nio.channels.OverlappingFileLockException at sun.nio.ch.SharedFileLockTable.checkList FileLockTable.java:255) By default ACS and ServerApp dfc.properties are pointing(…)

Script to suggest FK indexes

By Franck Pachot . In Oracle, when the referenced key is deleted (by delete on parent table, or update on the referenced columns) the child tables(s) are locked to prevent any concurrent insert that may reference the old key. This(…)

NOLOCK is definitely not what you may expect …

For those who still believe that using nolock hint is a lock-free process, keep reading this blog post. I wrote a previous blog post 3 years ago, when I was at one of my customer and(…)

Waiting for row lock. But which row is locked?

By Franck Pachot . When you are waiting on a locked row, the locked resource is the transaction that has locked the row. We have no information about which row is locked. Here is how to get it from V$SESSION.

Oracle: an unexpected lock behavior with rollback

By Franck Pachot . Here is an odd Oracle behavior I observed when a transaction that acquired a lock is rolled back. Note that this is related to a specific combination of locks that should not be encountered in(…)