Hello everyone, Today’s post addresses a common request we’ve encountered in our careers— the need to automatically initiate the Oracle database upon the reboot of a Linux server. The objective is to ensure that all databases, listeners, and other dependent services are up and running seamlessly where there is no Oracle Restarts configured, eliminating the need for manual intervention. This post will delve into how we can achieve this efficiently and swiftly using Linux services. T I am doing this test for Oracle 19c on RHEL7 but the steps are almost same for other DB or Types. Step 1 : Enable ..read more

Recently, I was working to simulate a production workload on a new server and analyze the potential impact of changes made to the Oracle Database. Armed with my favorite testing tool from Oracle, Real Application Testing (RAT), everything seemed to progress smoothly until I encountered a roadblock during the replay phase on the target system via workload clients (wrc replay clients). This incident occurred while conducting workload replay on Oracle Database 21c Release 3 within one of the Pluggable Databases (PDB). Yes, you read it right – replaying workload within a PDB! Since Oracle Release ..read more

Hi All, Here comes what is likely the final post of the year 2023! While there have been previous discussions on this topic, I’d like to delve deeper into the specific enhancements and features related to the use of the DUAL table in Oracle 23c and little more about this sweet little object in Oracle databases … The DUAL table has been a part of the Oracle Database for a very long time. It has been a fundamental component of Oracle’s SQL language for decades. The DUAL table in Oracle Database serves a specific purpose and is often used for various tasks. Its primary function is to provide a on ..read more

Hi All, Occasionally, anticipating the occurrence of a problem becomes unpredictable, and simultaneously, dealing manually with a transient issue to extract necessary information may not always be feasible (mainly due to the rapid resolution of the problem before we can initiate the extraction process). Additionally, there is a requirement for adaptability in the content we aim to extract. The ensuing approach allows us to attain our primary objectives without resorting to invasive measures. There could be multiple use cases, few of the scenarios would be : Case 1 : With little changes to it ..read more

Hi All, Recently, one of our custom monitoring scripts, which comprises more than 2000 lines of PL/SQL code covering all possible performance areas of the Oracle database, started behaving strangely on some 19c (19.15.0) databases. Usually, the report completes within 10-12 minutes on databases running version 12.2 and above, but it began taking approximately 30 minutes for a single run, with worst times exceeding 40 minutes. This issue seems to occur specifically on our 19c instances. During analysis, we identified one of the underlying SQL queries in our script that queries V$DIAG_ALERT_EXT ..read more

Hi All, In the past, I looked into a Database AWR performance report from a slow 19c where we suspected some IO issues and were looking into related metrics. “Tablespace IO Stats” was an important area and provided some important statistics like the average number of read requests per second, average read time in milliseconds, write waits, number of buffer waits, and average wait time in milliseconds for buffer waits for the tablespaces. While looking into the report, I saw that the said section was not there and was missing for Tablespace IO stats. It appeared that the file IO statistics for ..read more

Hi Everyone, Todays’ post was about an interesting scenario faced by my colleagues while they were doing an application upgrade and migration. Due to some reasons, the upgrade was supposed to be rolled back, and as a part of the strategy, they had to drop specific schemas touched by the failed upgrade and import a healthy backup taken just before the activity. The steps were simple and were well discussed and vetted. While doing the import, they started getting errors which reported about the AQ (Oracle Advanced Queues). The error pointed out that the import job had failed to create the AQs wi ..read more

Hi Guys, Recently I was working on one row locking contention where the a particular row was locked in exclusive mode caused all subsequent sessions trying to modify that row went in to waiting mode and were were waiting on ‘enq: TX row lock contention‘ wait event. This was a classic pessimistic row locking scenario which was happening due to application design problem. The situation is not new for most of the DBAs, and they know what is causing the block, the relationship of parent and child blockers, the blocking and block SIDs, lock modes etc., but things are sometimes difficult for non-DBA ..read more

Hi Guys, Recently while working on a Golden Gate setup Classic version 21 with XAG GI bundled agents version 9.1 (standalone deployment) on the top of Oracle 21.3.0 faced a strange issues where the GG failed to start and throwing errors .. CRS-2672: Attempting to start 'xag.ggtest.goldengate' on 'host' CRS-2674: Start of 'xag.ggtest.goldengate' on 'host' failed CRS-2679: Attempting to clean 'xag.ggtest.goldengate' on 'host' CRS-2681: Clean of 'xag.ggtest.goldengate' on 'host' succeeded CRS-4000: Command Start failed, or completed with errors. I checked for XAG errors in /diag/crs/crs_script ..read more

Recently while applying a WebLogic PSU Patch in an Oracle Hyperion-Essbase 14.x environment we encountered a weird issue where the patching utility was exceptionally slow while doing a rollback. We were using BSU (BEA Smart Update) utility to patch middleware homes and It took almost 95 minutes to rollback a patch in one of the lower environment. The slowness was most noticeable when its checking for conflicts in the system. It was surprising, I mean though BSU is an old utility (pre OPatch) but still is still the times are quite high to rollback a patch and was not acceptable. I have even inc ..read more