One of the presentations I went to at the DOAG conference earlier on this month was called “PL/SQL Tuning, finding the perf. bottleneck with hierarchical profiler” by Radu Parvu from Finland. If you do a lot of PL/SQL programming and haven’t noticed the dbms_hprof package yet make sure you take a good look at it.
A peripheral question that came up at the end of the session asked about problems with line numbers in pl/sql procedures; why, when (more...)
Let’s consider a hypothetical scenario. Suppose you have a process A that you want to run faster. This process doesn’t commit (much), so it doesn’t wait on log file sync. However, there is another multi-threaded process, B, that commits very frequently, and spends a lot of time on “log file sync”. You don’t care about the process B, your only goal is to make A go faster. After exhausting your tuning arsenal (to no avail), (more...)
In Oracle database version 184.108.40.206, Oracle introduced the Oracle In-Memory Database option. It is possible…
For whom are not familiar with PostgreSQL, it is an open source object-relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness. Like all other enterprise companies, we use different databases beside Oracle to lower the costs. We prefer PostgreSQL instead of Microsoft SQL Server, because it supports PL/SQL for some degree.
In this blog (more...)
There was a question on OTN a few days ago asking the following question:
Here’s a query that ran okay on 11g, but crashed with Oracle error “ORA-01843: not a valid month” after upgrade to 12c; why ?
The generically correct answer, of course, is that the OP had been lucky (or unlucky, depending on your point of view) on 11g – and I’ll explain that answer in another blog posting.
That isn’t the point of this (more...)
Last night was the Oracle Midlands Event #6 with Bjoern Rost.
Let’s start with the important stuff! I am now the proud owner of an Oracle Press bear! I didn’t technically win it, but one of the people who did donated it to me. This was the right thing to do for two reasons. (1) I wanted it more than him and (2) it is his fault I am in my current job, rather than (more...)
Those of you that have been around Oracle for some time may already be aware of the various OTN tours. These tours bring well known speakers to some of the smaller (relatively speaking) regions that often don’t get to see some of the big name speakers, simply because of audience size. Over the past couple of years, I’ve been involved in the OTN APAC tour, and recently returned from the New Zealand leg of the (more...)
Will you be joining us at the UKOUG Conference and Exhibition in Liverpool, UK? Over 200 world-class speakers and industry experts will be in attendance, including some of our very own.
Michael Abbey, Oracle ACE and Team Lead at Pythian notes that Pythian’s attendance is important, not only for the company and its employees, but for the Oracle community as a whole. “Pythian’s presence at UKOUG this year is the next chapter in an ongoing (more...)
One of the reasons I like user group conferences is meeting new people in my “area” – these people at the conference not only like technology and probably some of the same technology I do but, as they are at a conference, are probably inclined to learn stuff, meet people and maybe share ideas. I’m not actually very good face-to-face socially with people I do not know, so I like to tilt things in (more...)
I had a five-minute conversation with Oracle development Friday that rocked my world. I found out that parsing blocks stats which blocks parsing.
We have a system with queries that are taking minutes to parse. These queries include the main tables on our database, one of which is interval partitioned and has 20,000 sub-partitions. We have seen a situation where Oracle’s delivered statistics gathering job hangs on a library cache lock waiting (more...)
Database administrators, since the inception of their job descriptions, have been responsible for the protection of their organization’s most sensitive database assets. They are tasked with ensuring that key data stores are safeguarded against any type of unauthorized data access.
Since I’ve been a database tech for 25 years now, this series of articles will focus on the database system and some of the actions we can take to secure database data. We won’t (more...)
For the last couple of posts in this series I’ve been banging on about the importance of garbage collection (GC) in a flash system. I attempted to show you what happens if you don’t perform any GC at all (clue: you turn your flash device into a slow ROM), but clearly in the real world every flash array or SSD vendor has GC technology built into their flash translation layer. So why am I going (more...)
This query returns the top 5 wait events for the last hour from v$active_session_history view. Be careful, this view is part of the diagnostic pack, you should not query this view if you don’t have license for it. Top 5 wait events from v$active_session_history [crayon-5473514c88282132866302/] This is obviously an approximation, because v$active_session_history contains only 1 second samples, […]
The post Top 5 wait events from v$active_session_history appeared first on Oracle DBA Scripts and Articles (Montreal).
It's been a very long time not coming here, about 2 years and half ... and I missed it big time.
Now I moved to Oracle Systems (formerly Sun Microsystems) on a role support-programmer mixed, within RPE (Revenue Product Engineering) on the Extra Care team, with focus on Solaris, Engineered Systems with Solaris, ZFS Storage Appliance and Ops Center. I'm very happy since my job is closer to development, something was (more...)
I’ve previously discussed the new Zone Map database feature and how they work in a similar manner to Exadata Storage indexes. Just like Storage Indexes (and conventional indexes for that manner), they work best when the data is well clustered in relation to the Zone Map or index. By having the data in the table […]
At the NoCOUG fall conference at the eBay town hall in San Jose, we got a first-hand look at the workings of the most complex database environments in the world.(read more