As of EBS ICM Application DBA Online Patching ADOP Analyzer version 200.39
ADOP Analyzer was not updated for 19c databases:
Per 19c Database with Oracle E-Business Suite R12 Known Issues & Solutions ( Doc ID 2662860.1 )
Running ADZDDBCC.sql in 19c database is taking time for Section 26.
Before running report set parameter _px_cdb_view_enabled to false . alter session set “_px_cdb_view_enabled”=false ;
This is run both as part of 12.2 upgrade steps, and whenever you log an SR for ATG/ICM.
Work-around – add the “ALTER SESSION” command towards the top of the ADZDDBCC.sql – otherwise, on a 19c database, you’ll discover that when the dependency check portion runs, which looks like: SELECT col.owner, col.table_name, col.column_name, col.data_type_owner, col.data_type FROM dba_tables tab, dba_tab_columns col WHERE tab.owner IN (SELECT oracle_username FROM fnd_oracle_userid WHERE read_only_flag IN (‘A’, ‘B’, ‘E’, ‘U’)) AND col.owner = tab.owner AND col.table_name = tab.table_name AND col.data_type_owner NOT IN (‘APPS_NE’, ‘SYS’, ‘MDSYS’, ‘SYSTEM’) AND NOT EXISTS (SELECT 1 FROM SYSTEM.fnd_oracle_userid fou, fnd_product_installations fpi, ad_obsolete_objects aoo WHERE fpi.application_id = aoo.application_id AND fou.oracle_id = fpi.oracle_id AND fou.oracle_username = tab.owner AND aoo.object_name = tab.table_name AND aoo.object_type = ‘TABLE’) AND EXISTS (SELECT NULL FROM fnd_oracle_userid au, dba_users du WHERE au.oracle_username = du.username AND au.read_only_flag = ‘U’ AND du.editions_enabled = ‘Y’) <snip>
on 19c databases, you start seeing PX queue waits for every row fetch.
Adding the alter session avoids the queue/dequeue process occurring.
James Lui 2022 OATUG President OATUG Board of Directors
If you have a NetApp storage appliance, device, SAN, whatever you want to call it, review this first (NetApp Best Practices for Oracle Databases – published March 2014): http://www.netapp.com/us/media/tr-3633.pdf
The quick and dirty (for those experiencing Production issues right now):
The database-side init.ora:
grep filesystemio $ORACLE_HOME/dbs/initSID.ora
The options for filesystemio_options can be summarized as follows:
ASYNCH: Asynchronous I/O. Oracle should submit I/O requests to the operating system for processing. This permits Oracle to carry on with other work rather than waiting for I/O completion and increases parallelization of I/O.
DIRECTIO: Direct I/O. Oracle should perform I/O directly against physical files rather than routing I/O through the host operating system cache.
NONE: Use synchronous and buffered I/O. In these configurations, the choice between shared and dedicated server processes and the number of dbwriters will become more important.
SETALL: Use both asynchronous and direct I/O. (preferred for NetApp)
Note: The filesystemio_options parameter has no effect in DNFS and ASM environments. The use of Direct NFS (DNFS) or Automatic Storage Management (ASM) automatically results in the use of both asynchronous and direct I/O.
However…. Because you might end up cloning to an environment that doesn’t support DNFS (remember it’s stuck in the ORACLE_HOME/rdbms/lib object binary), you should have it set to SETALL anyway to allow fall-back to standard NFS (but with asynch and DI/O.).
[This refers to the: cd $ORACLE_HOME/rdbms/lib ; make -f ins_rdbms.mk [dnfs_on / dnfs_off] used to enable and disable DNFS (you also need the /etc/oranfstab created to support this – server: local: path: export: mount: etc…)]
If you have 126.96.36.199.x or later (12c) there’s a new DNFS-related init.ora parameter critical for managing packet requests by the database to avoid packet flooding the NFS file server: Without it (i.e. older versions) DNFS only works well on dedicated DNFS storage because an oracle database on modern hardware can easily over-whelm the NetApp’s ability to service TCP packets (can send upwards of 4,000+ requests per second)
Incidentally, if you want to measure your I/O rates, I have been using SLOB (Silly Little Oracle Basher – http://kevinclosson.wordpress.com/slob/ ) with one small modification to the iostat command in the runit.sh script to capture the I/O activity on all the shares (iostat -mn instead of -xm):
All this besides the usual OEM recommendations (bigger log_buffer, manage SGA size, get block sizes correct), dropped latency from over 40000ms to < 80ms on heavy load, and is producing 12000 IOPS on the same device.
This is an R12 e-Business Suite environment running on an 188.8.131.52.13 (PSU JAN2015) database (5TB).
What triggered this investigation was that the Log Writer process (LGWR) began dumping trace files about 6 months ago with entries that look like:
After investigating all the usual suspects about slow disk, I happened upon the aforementioned NetApp white paper. This occurs when multiple hosts are competing for resources under a single NetApp appliance environment (multiple enclosures, multiple dedicated or shared aggregates, etc.)
Every so often, system load on an e-Business Suite instance ramps up and response time to users starts climbing, often resulting in user observed errors such as:
FRM-92100 Your connect to the server has been interrupted
FRM-92102 A network error has occurred
Or sometimes, the screen just freezes (aka spins, stops, is broken, stuck, motionless, looks like a screen saver,can’t do anything, won’t work, froze-up, etc.) and the person has to close their browser, or even shut-down their workstation and restart.
Old technology often barks with unrelated error messages to the actual cause. If there’s a lot going on with concurrent requests, or interfaces, or analytic extracts running, the front-end response-time slows down, sometimes sufficiently to trigger these kinds of Form errors, even though technically there was no interruption to the network connectivity, either between the hosts, nor the workstation and the middle-tier application server.
However, on the database, the user-experience can be seen, although not necessarily in the place you might expect. OEM had introduced it’s Adaptive Metric Thresholds technology back in OEM 11g (in a slightly different place than in 12c (in Oracle Management Server/OMS 184.108.40.206.0). In OEM 11g, they were a link under the AWR Baseline Reports page.
On this page and in the list of Baseline Metrics, when you click into them, you can access the trending statistics being gathered for each metric. Many times this will provide direct insight into what a user experiences as the “the system is frozen” translates into “the back-end database response time is incredibly bad.”
In the example here, the database experienced a dramatic slow-down in response almost 5 to 10 times slower than usual, which only lasted a few seconds. But that can be enough to show up in many users’ sessions who might have just kicked off a query, or were trying to save something. Based upon the information gathered, we set the Warning and Critical thresholds to 1500ms and 2000ms respectively to start sending e-mail alert notifications upon breach of the levels. If the settings are left at “None”, no incident would be raised, and thus, no notification would be sent.
If you’re experiencing odd transient outages or sluggish behavior that defies the normal AWR and ADDM snapshot analysis, go take a look at what OEM has been gathering in the background over time and see if the statistics correlate to any of your issues. There’s value in that data. Just mine it.
In part 2 of this mini-series I’ll be describing the new mechanism for the simple frequency histogram and the logic of the Top-N frequency histogram. In part 3 I’ll be looking at the new hybrid histogram.
You need to know about the approximate NDV (number of distinct values) before you start examining the 12c implementation of the frequency and top-frequency histograms – but there’s a thumbnail sketch at the end of the posting if you need a quick reminder.
If you Care a Little More, Things Happen. Bees can be dangerous. Always wear protective clothing when approaching or dealing with bees. Do not approach or handle bees without proper instruction and training.
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