Category: Tips and Tricks

Feed: Striving for Optimal Performance. The contents of the V$SQL_CS_HISTOGRAM view is used by the SQL engine to decide when a cursor is made bind aware, and therefore, when it should use adaptive cursor sharing. For each child cursor, the view shows three buckets. It is of general knowledge that the first one (BUCKET_ID equal 0) is associated with the executions that process up to and including 1,000 rows, the second one (BUCKET_ID equal 1) with the executions that processes between 1,001 and 1,000,000 rows, and the third one (BUCKET_ID equal 2) with the executions that processes more than 1,000,000 ... Read More

Feed: Kamran Agayev's Oracle Blog. Last week we had a clusterware issue on one of the critical 3 node RAC environment. In the first node, network resource is restarted by ending up killing all sessions on that node abnormally. Oracle VIP that was running on that node failed over to the third node. The first node was up and running, but didn’t accept connections because it was trying to register the instance using LOCAL_LISTENER parameter where the oranode1-vip was specified that was not running on that node. We tried to relocate it back to the first node, but it failed ... Read More

Feed: SQL Server Customer Advisory Team. Author: Denzil Ribeiro. This article was co-authored by Dimitri Furman and Denzil Ribeiro Reviewed by: Danimir Ljepava, Borko Novakovic, Jovan Popovic, Rajesh Setlem, Mike Weiner Introduction In our ongoing engagements with the SQL DB Managed Instance preview customers a common requirement has been to monitor database workload performance in real time. This includes not just monitoring of a single (or a few) performance metrics, but being able to look at many relevant metrics at once, within seconds of events occurring. While much of the needed performance data is available in various DMVs, consuming it ... Read More

Feed: Kamran Agayev's Oracle Blog. Last month, after long brainstorm, I decided to take my chance and accepted my participation at Indian Oracle ODev Yathra tour. Despite the fact that I’ve visited India (Hyderabad) 2 times in the past for the Sangam conferences, I wanted to discover India more and decided to take 4 cities out of 7. For the Yathra Tour I submitted 2 papers: The first one was about “8 ways to migrate your On-Premis database to Oracle Cloud” where I was talking about different ways to migrate the database based on the downtime and the migration requirements ... Read More

Feed: Striving for Optimal Performance. In the last days, I am running a number of tests based on the TPC-DS benchmark against Oracle’s Autonomous Data Warehouse Cloud service (ADWC). One of the first thing I did is of course to create the TPC-DS schema and populate it. The aim of this blog post is to share some observations related to the population step. I started by generating the data with the tool provided by TPC-DS: dsdgen. With the following command, I generated 1TB of data: $ dsdgen -scale 1000 -dir /data/tpcdsdata The tool generated, in about 24 hours, the following ... Read More

Feed: Kamran Agayev's Oracle Blog. Posted by Kamran Agayev A. on July 25th, 2018 Most of you already have seen that Oracle Database 18c has been already released. If you haven’t downloaded and installed it yet, let’s do it! First of all, check the following address and download the installation of Oracle Database 18c: http://www.oracle.com/technetwork/database/enterprise-edition/downloads/oracle18c-linux-180000-5022980.html If you want to download it from the host itself, you can use wget by providing username, password and the installation zip file as follows: wget –http-user=YOUR_USERNAME –http-password=YOUR_PASSWORD –no-check-certificate –output-document=LINUX.X64_180000_db_home.zip “https://download.oracle.com/otn/linux/oracle18c/180000/LINUX.X64_180000_db_home.zip” If you want to get more information on this technique, check the following metalink ... Read More

Feed: SQL Server Customer Advisory Team. Author: Dimitri Furman. Reviewed by: Kun Cheng, Borko Novakovic, Jovan Popovic, Denzil Ribeiro, Rajesh Setlem, Arvind Shyamsundar, Branislav Uzelac In this article, we describe database storage architecture on Azure SQL Database Managed Instance (MI), for General Purpose (GP) instances specifically. We also provide a set of best practices to help optimize storage performance. At the time of this writing (July 2018), Managed Instance, both General Purpose and Business Critical, is in public preview. Some aspects of MI storage architecture will likely change as MI progresses from the current preview to general availability and beyond ... Read More

Feed: Striving for Optimal Performance. The Autonomous Data Warehouse Cloud (ADWC) service provides a Service Console that can be used to monitor the service activity and to carry out a small number of administration tasks (e.g. changing some resource management rules). The documentation specifically says to use the ADMIN user to login. But, actually, any unlocked database user having the CREATE SESSION privilege can be used to login. This is not only useful, but, in my opinion, necessary. In fact, developers should be able to see the service activity without knowing the password of the ADMIN user. The documentation provides ... Read More

Feed: SQL Server Customer Advisory Team. Author: Arvind Shyamsundar. Team members from Microsoft AzureCAT (a.k.a. DataCAT / SQLCAT) will be presenting a full-day pre-conference on “Building A Scalable Data Architecture In Azure” at the upcoming DPS 2018 conference in Bengaluru, India. We are very excited to be part of the 4th edition of Asia’s largest Microsoft data-focused conference, with over 1000 attendees expected overall. The motivation for this full-day pre-conference training is to share with attendees typical scenarios and considerations in architecting and implementing solutions on Microsoft Azure. Whether you are migrating an existing on-premises data pipeline, or implementing a ... Read More

Feed: Striving for Optimal Performance. The Appendix A of the Using Oracle Autonomous Data Warehouse Cloud guide describes the DBMS_CLOUD package. Unfortunately, it documents only a subset of the subroutines. And, for some of them, the description could also be enhanced. Therefore, while I was testing all the subroutines the DBMS_CLOUD package provides, I took a number of notes. By the end of my tests, I got what I can call my personal reference guide to the package. Since it might help others, here it is… Introduction To interact with other cloud services, the Oracle Autonomous Data Warehouse Cloud service ... Read More