100500 ways of caching in Oracle Database

100500 ways of caching in Oracle DatabaseTelling what caches are, what a Result Cache is, how it is made in Oracle and in other databases is not very interesting and rather patterned. But everything gets completely different colors when it comes to specific examples.
Alexander Tokarev
( Shtock ) Built his report on Highload ++ 2017 on the basis of cases. And it was based on the cases, he told me when the home-made cache can be handy, what the pain of the server-side Result Cache is and how to replace it with the client, and in general brought up a number of useful tips for setting up Result Cache in Oracle.
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Summer Mitap Apache Ignite in St. Petersburg

Summer Mitap Apache Ignite in St. Petersburg  
Friends, we invite you to the summer Mitap, dedicated to Apache Ignite. Join our informal meeting of users and developers. There will be new speakers, new topics and ice cream. With you bring interesting questions and summer mood.

June 2? St. Petersburg

on the meeting page (authorization via Facebook or Google takes only a couple of minutes).
Location: St. Petersburg, Kuznechny Lane ? studio 18/39 (in the courtyard), 2 minutes walk from the metro Vladimirskaya /Dostoevskaya.
Video Records at the ...[/h]
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Patch me if you can: how do we debug production. Part 2

Patch me if you can: how do we debug production. Part 2In the first part of his articles I talked about how we in Badoo created the first version of the patch system. In short, we needed to find a way to correct serious mistakes directly on production, available to all developers. However, the first version was not without flaws: we used a kind of layout that did not allow us to guarantee the atomicness of the patch calculations and the consistency of the code.
In this part of the article, I'll tell you about a new way of laying out the code that we came up with trying to solve our problems, and how our patch system changed with it.
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Heterogeneous competitive data processing in real time is strictly one time

Heterogeneous competitive data processing in real time is strictly one time
Real-time data processing exactly once (
) - the task is extremely non-trivial and requires a serious and thoughtful approach throughout the entire calculation chain. Some even believe that such a problem is impossible. . In reality, one wants to have an approach that ensures fault-tolerant processing in general without any delays and the use of various data stores, which puts forward even more stringent requirements for the system:
concurrent exactly-once
and the heterogeneity of the persistent layer. To date, this requirement does not support any of the existing systems.
The p...
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Data warehouse performance: new digits

Data warehouse performance: new digitsIn our previous post, we shared our measurements of hypervisor performance after installing patches against the vulnerabilities of Meltdown and Specter. Today it's time to talk about the performance of the data warehouse.
Thanks to the optimizations of VzKernel and its recompilation with the "Retpoline" option, we replaced the vulnerable machine code sequences and almost completely eliminated the performance problems caused by the need to protect the hypervisor from vulnerabilities in Intel processors. As a result, the decrease in productivity was reduced to 1-2%. However, against this ...
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Secure interaction in distributed systems

Secure interaction in distributed systems
Hello Habr!
My name is Alexey Solodky, I'm a PHP developer at Badoo. And today I will share the text version of my report for the first Badoo PHP Meetup. Videos of this and other reports with the mitapa can be found here .
Any system consisting of at least two components (and if you have both PHP and the database, it's already two components), encounters whole classes of risks in the interaction between these components.
The platform department in which I work integrates new internal services with our application. And solving these problems, we have accumulated experience, which I want ...
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A few words about the actual performance of the hypervisor

Users of virtualized systems, and especially service providers, very often wonder: "how to squeeze the maximum out of the existing hardware?" And in this context, we often have to discuss the KVM hypervisor and the differences between the different versions of Virtuozzo. In this post, we will talk about a series of tests of the latest virtualization system along with real-performance estimates for typical loads, as well as Meltdown and Specter patches.
Enter , you are welcome.
Which hypervisor parameters do you consider more important?
The density of placement is
Support for different ...
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Monitoring the performance of the disk subsystem using zabbix and block stat

Hardly anyone will argue that monitoring the performance of the disk subsystem is almost the most important task for all highly loaded storage systems and databases. I initially ran into this a long time ago, even when I had to watch PostgreSQL. Recently, I returned to this issue in connection with the need to test various storage facilities.
Today I want to share my current experience with the community on the real example of zabbix and its connection with the block stat.
Monitoring the performance of the disk subsystem using zabbix and block stat  
habr.com/post/165855 . I'll tell you - it's terribly inconvenient.
Where ...
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Overview and testing of Infortrend EonStor DS2024 2nd generation

Overview and testing of Infortrend EonStor DS2024 2nd generation In the article "Infortrend storage is an alternative to A-brands. Review and Testing » we described the functionality and performance of one of the most popular at the time SAN Infortrend - DS 3012T. To the advantages of Infortrend storage, following the results of the last article, we classified the support of classic Enterprise disks (not branded ones) and the operation of SATA disks in 2-controller systems. These facts make the storage system data unique, because using SATA SSD Enterprise, you can build a low-cost storage system with high performance and fault tolerance.
In this article, we'll look ...
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Tips for optimizing Java code: how not to step on the rake

Tips for optimizing Java code: how not to step on the rakeGood evening, colleagues.
The translation of the article that we will propose to you today is designed to help answer the question: was the need for an entire book on optimizing Java code necessary? We hope that the material will not only seem interesting to you, but it will also come in handy in practice. Please do not forget to vote.
VisualVM (free) and JProfiler (paid - but absolutely worth their money).
Armed with such information, you can rest assured that you are optimizing exactly the code that is required - and that the effect of the changes you make can be measured
We w...
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