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Database Feed

Oracle Database, Oracle 10g, Oracle 11g, Oracle XE, Oracle RAC, Oracle Instant Client, Oracle Data Guard and Oracle Exadata resources, news, and support articles.

Unusual Deadlock

Prompted by a question on OTN I came up with a strategy for producing an ORA-00060 deadlock that DIDN’T produce a deadlock graph (because there isn’t one) and didn’t get reported in the alert log (at least, not when tested on 11.2.0.4). It’s a situation that shouldn’t arise in a production system because it’s doing the sorts of things that you shouldn’t do in a production system: but possibly if you’re trying to do some maintenance or upgrades while keeping the system live it could happen.

Oracle Database 12.1.0.2.0 – Getting started with JSON Path Expressions

Yesterday my colleague Alex and I had the pleasure to do some extra presentations during AMIS’s Oracle OpenWorld preview evening. While still not getting around...
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Side effects of disabling BEQ protocol

Hi,

I have ORACLE 11g client and server in a single machine. I run an application which has its own signal handling. Since BEQ is hosting processes i get errors in my application functioning (which works absolutely fine when client and server are hosted in different machines).

I want to know what are side effects of disabling BEQ protocol?

Can anybody please advice?

RMAN – The pocket knife of the DBA – Part 1

One area which has always interested me within the Oracle ‘world’ is Backup and Recovery, and there is one utility in particular that I think stands out – RMAN. Oracle Recovery Manager, or RMAN as it is widely known, is one of the most important database utilities, and one that every Oracle DBA should be […]

Oracle OEM Cloud Control 12.1.0.4 - AWR Warehouse

This post explains how to configure and use the new AWR warehouse functionality present in Enterprise Manager Cloud Control 12.1.0.4. This new feature offers the possibility to store date from the AWR of your main databases in the EM AWR warehouse.

Documentum upgrade project - Documentum Administrator and ACS

After having installed the Documentum Administrator, one of our test was to open a document. When I opened one for the first time the content was empty although I knew it contained text. But the correct content was well displayed when I opened it a second time.
In the ucf trace file I had:
 

inmemory: Why did that table was not populated in the column store?

I enabled an huge 70G table for inmemory population, I expected the inmemory population to take a while, but the population didn’t complete even after letting it run for a day. Why?

ASH data

Initial review of the server shows no issues, no resource starvation. This must be a problem with Oracle processes itself. I started digging further, and ASH data shows that in numerous samples the process was seen reading block using single block I/I calls. Also object_id matches with the table I was trying to populate.

Spreading Out Data – Old School Methods

In the previous post in this series we introduced a crude test case in which we had data packed in to a single block which was causing severe buffer contention. To re-cap – here is a chart of ASH data demonstrating the issue, the large grey stripe is time wasted on global cache contention.

How to See When Your Database Was Opened

This was tested on Oracle 11.2: 

inmemory: sa00 process

After the restart of a 12c inmemory database with 300GB+ SGA, I noticed that an Oracle background process sa00 was consuming a bit of CPU. Documentation suggests that it is SGA Allocator process, however, ipcs -ma command shows that the shared memory segment is already allocated. I was curious, of course, what would that background process will be allocating?.

pstack

Process stack of the process shows that it is touching SGA pages to pre-page SGA memory pages.

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