Monitoring Commit Times Without Application Instrumentation in Oracle
Learn how knowing log file sync wait times in Oracle enables a good database commit time approximation, and how this can help you better tune performance.
Read MoreMost Popular Wait Events
Types of Oracle Wait Events
Oracle DBAs frequently classify wait events into four main categories: Foreground, Background, Idle, and Non-Idle events. Learn more.
Read MoreAbout Oracle RAC Global Cache CR Request Wait Event
Learn how to diganose and tune for Oracle RAC global cache cr request or gc cache cr request wait events.
Read MoreUnderstanding Oracle Write Complete Waits
If a session spends a lot of time waiting on the Oracle write complete waits event, it is usually due to a slow I/O subsystem, the MTTR is too short or the DBWR write batch size is too large.
Read MoreUnderstanding Oracle Free Buffer Wait Events
Oracle free buffer waits are caused by inefficient SQL statements, not enough DBWR processes, slow I/O subsystems, delayed block cleanouts and/or small buffer caches.
Read MoreUnderstanding Oracle Log Buffer Space Wait Events
The Oracle log buffer space wait event can indicate that the log buffer in the SGA is too small or the LGWR process is too slow.
Read MoreSolving Oracle Log File Sync Waits Caused by High Commit Frequency
High commit frequency is the number one cause for foreground log file sync waits in Oracle. Learn how to diagnose and tune for these waits.
Read MoreDiagnosing Oracle Wait for TX Enqueue in Mode 4–Bitmap Index Entry
Diagnose Oracle waits for TX enqueue in mode 4 that are caused by multiple sessions attempting to update or delete different rows covered by the same bitmap entry.
Read MoreDiagnosing Oracle Wait for TX Enqueue in Mode 4–Unique Key Enforcement
Unique or primary key enforcement may cause Oracle enq: TX—row lock contention, indicating an application issue outside the database.
Read MoreDiagnosing Oracle Wait for TX Enqueue in Mode 4–ITL Shortage
Learn how to diagnose Oracle waits for TX enqueue in mode 4 that are caused by ITL (interested transaction list) shortage.
Read MoreDiagnosing Oracle Wait for TX Enqueue in Mode 6 (Row Lock Contention)
A wait for the Oracle TX enqueue in mode 6 (row lock contention) is a common enqueue wait, and occurs when a transaction tries to update or delete rows that are currently locked by another transaction.
Read MoreWhat Does the Oracle Latch Free Wait Event Tell You?
Oracle latch free wait events mean the process failed to obtain the latch in the willing-to-wait mode after spinning _SPIN_COUNT times and went to sleep. Learn more about what this can mean.
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