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• The Next-gen Databases

  - by Randin

  I'm learning traditional Relational Databases (with PostgreSQL) and doing some research I've come across some new types of databases. CouchDB, Drizzle, and Scalaris to name a few, what is going to be the next database technologies to deal with?

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• How to backup my MySQL's databases on Windows Vista?

  - by MCardinale

  Hello. How can I backup my MySQL's databases? I'm using Windows Vista and MySQL 5.1. I have found the folder "C:\Users\All Users\MySQL\MySQL Server 5.1\data" with all my database files and copy them, but how can I restore them if I need? Thank you.

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• Object Oriented vs Relational Databases

  - by Dan

  Objects oriented databases seem like a really cool idea to me, no need to worry about mapping your domain model to your database model, no messing around with sql or ORM tools. The way I understand it, relational DBs offer some advantages when there is massive amounts of data, and searching an indexing need to be done. To my mind 99% of websites are not massive, and enterprise issues never need to be thought about, so why arn't OO DBs more widely used?

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• methods of joining 2 tables without using JOIN or SELECT more than one distinct table in the query

  - by GB_J

  Is there a way of joining results from 2 tables without using JOIN or SELECT from more than one table? The reason being the database im working with requires queries that only contain SELECT, FROM, and WHERE clauses containing only one distinct table. I do, however, need information from other tables for the project i'm working on. More info: the querier returns the query results in a .csv format, is there something we can manipulate there?

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• Oracle/SQL table attribute question

  - by UnceRawr

  I have been given a context schema for a database i need to make for my coursework but some of the attributes (column names) contain letters in brackets at the end of them such as: *x_Number (Adm) *x_Number (A) *x_Number (P) The problem is i have no idea what these letters mean! Can anyone help?

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• Q&A: Oracle's Paul Needham on How to Defend Against Insider Attacks

  - by Troy Kitch

  Source: Database Insider Newsletter: The threat from insider attacks continues to grow. In fact, just since January 1, 2014, insider breaches have been reported by a major consumer bank, a major healthcare organization, and a range of state and local agencies, according to the Privacy Rights Clearinghouse.  We asked Paul Needham, Oracle senior director, product management, to shed light on the nature of these pernicious risks—and how organizations can best defend themselves against the threat from insider risks. Q. First, can you please define the term "insider" in this context? A. According to the CERT Insider Threat Center, a malicious insider is a current or former employee, contractor, or business partner who "has or had authorized access to an organization's network, system, or data and intentionally exceeded or misused that access in a manner that negatively affected the confidentiality, integrity, or availability of the organization's information or information systems."  Q. What has changed with regard to insider risks? A. We are actually seeing the risk of privileged insiders growing. In the latest Independent Oracle Users Group Data Security Survey, the number of organizations that had not taken steps to prevent privileged user access to sensitive information had grown from 37 percent to 42 percent. Additionally, 63 percent of respondents say that insider attacks represent a medium-to-high risk—higher than any other category except human error (by an insider, I might add). Q. What are the dangers of this type of risk? A. Insiders tend to have special insight and access into the kinds of data that are especially sensitive. Breaches can result in long-term legal issues and financial penalties. They can also damage an organization's brand in a way that directly impacts its bottom line. Finally, there is the potential loss of intellectual property, which can have serious long-term consequences because of the loss of market advantage.  Q. How can organizations protect themselves against abuse of privileged access? A. Every organization has privileged users and that will always be the case. The questions are how much access should those users have to application data stored in the database, and how can that default access be controlled? Oracle Database Vault (See image) was designed specifically for this purpose and helps protect application data against unauthorized access.  Oracle Database Vault can be used to block default privileged user access from inside the database, as well as increase security controls on the application itself. Attacks can and do come from inside the organization, and they are just as likely to come from outside as attempts to exploit a privileged account.  Using Oracle Database Vault protection, boundaries can be placed around database schemas, objects, and roles, preventing privileged account access from being exploited by hackers and insiders.  A new Oracle Database Vault capability called privilege analysis identifies privileges and roles used at runtime, which can then be audited or revoked by the security administrators to reduce the attack surface and increase the security of applications overall.  For a more comprehensive look at controlling data access and restricting privileged data in Oracle Database, download Needham's new e-book, Securing Oracle Database 12c: A Technical Primer. 

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• How security of the systems might be improved using database procedures?

  - by Centurion

  The usage of Oracle PL/SQL procedures for controlling access to data often emphasized in PL/SQL books and other sources as being more secure approach. I'v seen several systems where all business logic related with data is performed through packages, procedures and functions, so application code becomes quite "dumb" and is only responsible for visualization part. I even heard some devs call such approaches and driving architects as database nazi :) because all logic code resides in database. I do know about DB procedure performance benefits, but now I'm interested in a "better security" when using thick client model. I assume such design mostly used when Oracle (and maybe MS SQL Server) databases are used. I do agree such approach improves security but only if there are not much users and every system user has a database account, so we might control and monitor data access through standard database user security. However, how such approach could increase the security for an average web system where thick clients are used: for example one database user with DML grants on all tables, and other users are handled using "users" and"user_rights" tables? We could use DB procedures, save usernames into context use that for filtering but vulnerability resides at the root - if the main database account is compromised than nothing will help. Of course in a real system we might consider at least several main users (for example frontend_db_user, backend_db_user).

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• "[INS-30131] Initial setup required for the execution of installer validations failed." Encountering this error while installing Oracle database 12c. [on hold]

  - by user132992

  I am trying to install Oracle 12c database on my machine running Fedora 20. And I am encountering this problem: "[INS-30131] Initial setup required for the execution of installer validations failed." And when we see the details then it is like this: Cause - Failed to access the temporary location. Action - Ensure that the current user has required permissions to access the temporary location. Additional Information: - Framework setup check failed on all the nodes - Cause: Cause Of Problem Not Available   - Action: User Action Not Available Summary of the failed nodes fedora - Version of exectask could not be retrieved from node "fedora"   - Cause: Cause Of Problem Not Available   - Action: User Action Not Available To eliminate this error I have tried various measures including the change of permission of the tmp folder and restarting the computer but none is working. Plz someone help me out of this. Any kind of help will be appreciated...

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• NFS (with Kerberos) mount failing due to "Server not found in Kerberos database" error

  - by Kendall Hopkins

  When running: `sudo mount -t nfs4 -o sec=krb5 sol.domain.com:/ /mnt` I get this error on the client: mount.nfs4: access denied by server while mounting sol.domain.com:/ And on the server syslogs UNKNOWN_SERVER: authtime 0, nfs/[email protected] for nfs/ip-#-#-#-#[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for nfs/ip-#-#-#-#[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database UNKNOWN_SERVER: authtime 0, nfs/[email protected] for krbtgt/[email protected], Server not found in Kerberos database Server keytab file: ubuntu@sol:~$ sudo klist -e -k /etc/krb5.keytab Keytab name: WRFILE:/etc/krb5.keytab KVNO Principal ---- -------------------------------------------------------------------------- 7 host/[email protected] (aes256-cts-hmac-sha1-96) 7 host/[email protected] (arcfour-hmac) 7 host/[email protected] (des3-cbc-sha1) 7 host/[email protected] (des-cbc-crc) 9 nfs/[email protected] (aes256-cts-hmac-sha1-96) 9 nfs/[email protected] (arcfour-hmac) 9 nfs/[email protected] (des3-cbc-sha1) 9 nfs/[email protected] (des-cbc-crc) Client keytab file: ubuntu@mercury:~$ sudo klist -e -k /etc/krb5.keytab Keytab name: WRFILE:/etc/krb5.keytab KVNO Principal ---- -------------------------------------------------------------------------- 3 host/[email protected] (aes256-cts-hmac-sha1-96) 3 host/[email protected] (arcfour-hmac) 3 host/[email protected] (des3-cbc-sha1) 3 host/[email protected] (des-cbc-crc) 3 nfs/[email protected] (aes256-cts-hmac-sha1-96) 3 nfs/[email protected] (arcfour-hmac) 3 nfs/[email protected] (des3-cbc-sha1) 3 nfs/[email protected] (des-cbc-crc)

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• Database which only holds indexes and last X records in memory?

  - by Xeoncross

  I'm looking for a data store that is very memory efficient while still allowing many object changes per second and disregarding ACID compliance for the last X records. I need this database for a server with not much memory and I can make a key-value store, document, or SQL database work. The idea is that indexes/keys are the only thing I need in memory and all the actual values/objects/rows can be saved on disk do to the low read rate (I just want index/key lookup to be fast). I also don't want records constantly being flushed to disk, so I would like the last X number of records to be held in memory so that 100 or so of them can all be written at once. I don't care if I lose the last 10 seconds worth of objects/values. I do care if the database as a whole is in danger of becoming corrupt. Is there a data-store like this?

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• Migrating master-slave MySQL database servers to 2 new servers, any tips or suggestions?

  - by mmattax

  I'm setting up 2 new database servers that will be replacing a current master-slave setup. All boxes are running / will be running MySQL on RHEL. Our current naming conventions: db1 - master database db2 - slave (using MySQL replication) db01 - new master db02 - new slave We need to get db01 to be the new master with db02 as the new slave. What is the best way to migrate db1 and db2 to db01 and db02? db1 and db2 are running in a production setting and we need to minimize all downtime; db1 has roughly 30GB of data in the database. Any suggestions or tips on how to migrate to our new servers would be much appreciated.

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• Windows authenticated users have lost access to master (default) database

  - by Rob Nicholson

  Something very strange has occurred on our production SQL database. Users connecting via Windows authentication appear to have lost all access to the master database. By default, all logins have the default database set to master. So when you connect using SQL Server management studio, they get the error: "Cannot open user default database. Login failed error 4064". What's also worrying is that we have a group called "COMPANY - SQL Administrator" which has sysadmin rights and users in this group also get the same error. Worse, they don't appear to be system administrators anymore... If they change their default database to something else, they can connect and then work on the database, it's just the master database that is problematic. I'm not even sure by what mechanism windows authenticated users get access to the master database. Is it something hard coded in or some property that's got changed? Any ideas? Cheers, Rob.

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• Can I convert my database/script to UTF-8 ?

  - by Mohannad Otaibi

  How can I convert a database to support UTF-8 and convert it's old data from what ever encoding they're in to UTF-8 ? Extra Info: I'm running a server which has many websites on it, and one of them is running WHMCS (php script to manage hosting clients). WHMCS has an iPhone application where i can browse it through iPhone, the problem is that this application will only run if everything in my website is in UTF-8 encoding. I was using windows-1256 as encoding in my script's settings, and i tried changing that in some point of time to UTF-8 for a while then changed it back to windows-1256 so, the data in the database are some inserted using UTF standards and most of them are windows-1256 If someone could clear the picture for me, Do I need to convert every database on the server or just one DB ? what should I change? If i had to do that manually, I'll do it but I need some expert advise.

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• DBA Command line options

  - by Anthony Shorten

  There are a number of database utilities supplied with the installation of the Oracle Utilities Application Framework based products. These are typically run in interactive mode where the utility prompts you for the values and then executes the required functionality. Did you know that the utilities also have command line options that allow you to run the utility in silent mode as well? You can assess the command line options by specifying the -h option on the command line. Here is an example of the oragensec command line options: oragensec -d <Owner,OwnerPswd,DbName> -u <Database Users> -r <ReadRole,UserRole> -l <logfile> -h where: -d <Owner,OwnerPswd,DbName> Database connect information for the target database. e.g. spladm,spladm,DB200ODB. -u <Database Users> A comma-separated list of database users where synonyms need to be created. e.g. spluser, splread -r <ReadRole,UserRole> Optional. Names of database roles with read and read-write privileges. Default roles are SPL_READ, SPL_USER. e.g. spl_read,spl_user -l <logfile> Optional. Name of the log file. -h Help The command line options allow the DBA to automate the exeucution either via a script or some utility can than execute utilities. This optin can apply to the majority of DBA utilities supplied with the product. Take a look at others.

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• SQL SERVER – Identify Most Resource Intensive Queries – SQL in Sixty Seconds #029 – Video

  - by pinaldave

  There are a few questions I often get asked. I wonder how interesting is that in our daily life all of us have to often need the same kind of information at the same time. Here is the example of the similar questions: How many user created tables are there in the database? How many non clustered indexes each of the tables in the database have? Is table Heap or has clustered index on it? How many rows each of the tables is contained in the database? I finally wrote down a very quick script (in less than sixty seconds when I originally wrote it) which can answer above questions. I also created a very quick video to explain the results and how to execute the script. Here is the complete script which I have used in the SQL in Sixty Seconds Video. SELECT [schema_name] = s.name, table_name = o.name, MAX(i1.type_desc) ClusteredIndexorHeap, COUNT(i.TYPE) NoOfNonClusteredIndex, p.rows FROM sys.indexes i INNER JOIN sys.objects o ON i.[object_id] = o.[object_id] INNER JOIN sys.schemas s ON o.[schema_id] = s.[schema_id] LEFT JOIN sys.partitions p ON p.OBJECT_ID = o.OBJECT_ID AND p.index_id IN (0,1) LEFT JOIN sys.indexes i1 ON i.OBJECT_ID = i1.OBJECT_ID AND i1.TYPE IN (0,1) WHERE o.TYPE IN ('U') AND i.TYPE = 2 GROUP BY s.name, o.name, p.rows ORDER BY schema_name, table_name Related Tips in SQL in Sixty Seconds: Find Row Count in Table – Find Largest Table in Database Find Row Count in Table – Find Largest Table in Database – T-SQL Identify Numbers of Non Clustered Index on Tables for Entire Database Index Levels, Page Count, Record Count and DMV – sys.dm_db_index_physical_stats Index Levels and Delete Operations – Page Level Observation What would you like to see in the next SQL in Sixty Seconds video? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video Tagged: Excel

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• How to use Nginx to export the mongoDB connection?

  - by Totty

  I have on my server 2 things: the node.js server and a mongodb database; The node.js server is reachable from myip/server; and now I would like to export the mongodb database to myip/database for example. Now when I use my mongodb viewer (MongoVUE) with "http://myip/database:9000" (the port 9000 is set in nginx and it's also the port that I start mongod). If I go to "http://myip/database:9000" or "http://myip/database" in a browser it look like: "You are trying to access MongoDB on the native driver port. For http diagnostic access, add 1000 to the port number". But in MongoVUE it says: Unable to connect to server 192.168.1.16/database:9000: No such host is known. Type: MongoDB.Driver.MongoConnectionException Stack: at MongoDB.Driver.Internal.DirectConnector.Connect(TimeSpan timeout) at MongoDB.Driver.MongoServer.Connect(TimeSpan timeout, ConnectWaitFor waitFor) at MongoDB.Driver.MongoServer.Connect(TimeSpan timeout) at MongoDB.Driver.MongoServer.Connect() at MangoUI.MMongo.FQlxNlJKqO74gYmXgZR4(Object ) at MangoUI.MMongo.Open(Boolean useSamus) at MangoUI.MMongo.Open() at MangoUI.ComNavTree.wJQdUqApCpjoC39P59n(Object ) at MangoUI.ComNavTree.ExpandMe(MTreeNode expand) at MangoUI.ComNavTree.tree_BeforeExpand(Object sender, TreeViewCancelEventArgs e) No such host is known Type: System.Net.Sockets.SocketException Stack: at System.Net.Dns.GetAddrInfo(String name) at System.Net.Dns.InternalGetHostByName(String hostName, Boolean includeIPv6) at System.Net.Dns.GetHostAddresses(String hostNameOrAddress) at MongoDB.Driver.MongoServerAddress.ToIPEndPoint(AddressFamily addressFamily) at MongoDB.Driver.MongoServerInstance.Connect(Boolean slaveOk) at MongoDB.Driver.Internal.DirectConnector.Connect(TimeSpan timeout)

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• Items cannot be installed or removed

  - by Gyanendra Kumar Gyan

  installArchives() failed: (Reading database ... (Reading database ... 5% (Reading database ... 10% (Reading database ... 15% (Reading database ... 20% (Reading database ... 25% (Reading database ... 30% (Reading database ... 35% (Reading database ... 40% (Reading database ... 45% (Reading database ... 50% (Reading database ... 55% (Reading database ... 60% (Reading database ... 65% (Reading database ... 70% (Reading database ... 75% (Reading database ... 80% (Reading database ... 85% (Reading database ... 90% (Reading database ... 95% (Reading database ... 100% (Reading database ... 136187 files and directories currently installed.) Removing pidgin-ppa ... gpg: key "67265EB522BDD6B1C69E66ED7FB8BEE0A1F196A8" not found: eof gpg: 67265EB522BDD6B1C69E66ED7FB8BEE0A1F196A8: delete key failed: eof dpkg: error processing pidgin-ppa (--remove): subprocess installed post-removal script returned error exit status 2 No apport report written because MaxReports is reached already Processing triggers for ureadahead ... ureadahead will be reprofiled on next reboot Errors were encountered while processing: pidgin-ppa Error in function: SystemError: E:Sub-process /usr/bin/dpkg returned an error code (1)

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• Database Driven Web Application, C# Front-End and F# Back-End meaning

  - by user1473053

  Hi I am an intern working with ASP.NET. My current task is to make a website which will incorporate some jquery viewing features. This project seems to me will be primarily dealing with reading data from a database and making graphs out of them. This will require me to make custom queries from whatever the client is looking at. I think it is going to be what this guy calls an Ad Hoc Query tool My plan for this is to make it a database-driven website. So I can utilize the jquery dynamic viewing capabilities. I stumbled upon the functional programming paradigm and found F#. I read that because of it's functional programming paradigm, it makes it a good language to do asynchronous functions. I read about how you can use this with LINQ to SQL and how easy it is to make queries without actually putting the query language in. I understand the concept of the MVC design pattern. But I don't understand what they mean about C# being the front-end and F# being the back-end. Can someone clarify this to me? Also what are your thoughts about doing this project in this way? Any comments and thoughts are greatly appreciated. I feel as if learning F# will be a great learning experience for me. My guess is that the F# back-end is like the part where it controls the calls to the database. F# is possibly the model part of the design pattern. And C# is the controller. So HTML, Javascript and Jquery stuff will be my View design pattern. Clarify please?

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• Build vs Buy Webcast: November 8, 2012

  - by TammyBednar

  Date: Thursday, November 8, 2012, 1:00 PM EST You have a choice. Do you build your own database platform or buy a pre-engineered database appliance? Building a high-availability database platform presents unique challenges. Combining servers, storage, networking, OS, firmware, and database is complicated and raises important concerns: Will coordination between multiple SME’s delay deployment? Will it be reliable? Will it scale? Will routine maintenance consume precious IT-staff time? Ultimately, will it work? Enter the Oracle Database Appliance, a complete package of software, server, storage, and networking that’s engineered for simplicity. It saves time and money by simplifying deployment, maintenance, and support of database workloads. Plus, it’s based on Intel Xeon processors to ensure a high level of performance and scalability. Attend this Webcast to hear customer stories and discover how the Oracle Database Appliance: Increases ROI by reducing capital and operational expenses Frees IT staff by reducing deployment and management time from weeks to hours Takes the worry out of supporting mission critical application workloads Register For this WebCast today!

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• ?Oracle DB 11gR2 ??????????????????/????????????????!

  - by Yuichi.Hayashi

  ?????????????????????????????40~60%????????????? ??????????????????????????????????????????????????????????????????????????????????... ????????????????????????????????????????TCO(Total Cost of Ownership)???????????? ??????????????????????????????????????????????????????????????????????????? ???????1?1???????????????????????????????????1??????????????????????????????????????·????????????? ??????????????????·???·????????????????TCO????????????? ????????????????Grid(????)????????????????????????????·???? = Oracle Real Application Clusters(RAC)???????·???? = Oracle Automatic Storage Management(ASM)????????????????????????????????????? Oracle Database???????11g R2?????????????????????????/???????????????????????(????????????????)?????????????????????????????! SCAN Single Client Access Name(SCAN)??Oracle Real Application Clusters(RAC)11g R2??????? SCAN??????????????????????????????????????????????????RAC?????????????????????????·????????????????????SCAN?????????????????????VIP?????????????RAC????????????????????????????????!???????????????? ???????????????????????????????????????SCAN?????????????????????????????TCO?????????????????(????????????)???????????????????????????????!????????????? SCAN?????????????????????? ??????Oracle Database 11gR2 Real Application Clusters(?????????) ??????Oracle Real Application Clusters 11g Release 2 SCAN??? ACFS ASM Cluster File System(ACFS)??Automatic Storage Management(ASM)11g R2??????? ASM??S.A.M.E.(Stripe And Mirror Everything)????????????????????????????????????????????????????????·???????·??????????????????10g????????????????·??????????·???????????????ASM????????????·??????????????????????????????????????????·?????????????????????????????????????????????? 11g R2??????ACFS?????????????????(????????????????????????????????????????????????????????)????ASM???????????????????????????????????????????????????????·??????????????ACFS????! · ??????????????????? · ????????????/???? · ??????????????????????(?????)??? · ????????????? ?2???????????????????????????? · ???????????? ??????????????????????·??????????·?????????????????????!???????????????????????????????????????? ACFS??????????????????? ??????Oracle Database 11gR2 Automatic Storage Management ??????Oracle Database 11g Release 2 Automatic Storage Management???????????????? ??????·????? ??????·???????Oracle Database Resource Manager(????·?????)11g R2??????? ????·????????????·???????????????????????????????Oracle Database???Oracle RAC????????????????????????????????????????????????????????????????????????????????????????????????????1????????????? ????????????·?????????????????????????????????????????????????????????????????? CPU ???????????????????????????????????????????????????·??????????????????????????? 11g R2??????????·???????????????? CPU_COUNT ?????????????? CPU ???????????????????????????·??????? CPU ?????????????????????????????????????????????? ????????·???????????????????????????????????????????Oracle ??????????????????????·??????? CPU ??????????????????????????????·???????????????!???????????????? ??????·???????????????????????? ??????Oracle Database 11gR2 ????????????? ?????????? ? ??????????????????????????????????!? ? ???????????????????????????????????!?

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• Why does mobile first responsive design tend to not use max-width queries alongside the min-width queries?

  - by Sam

  First off, I understand the basic principles behind mobile first responsive web design, and totally agree with them. But one thing I don't understand: In my experience, not all styles for small screens can be used for the larger version of a website. For example, usually smaller versions tend to have larger clickable areas, hamburger navigation, etc. So I sometimes have to override these specific styles, aside from just progressively enhancing the base styles. So I was wondering: why is max-width rarely mentioned (or used) in the context of mobile-first responsive web design? Because it looks like it could be used to isolate styles for smaller screens that are not useful for larger screens, and would thus prevent unnecessary duplication of code. A quote which mentions min-width as typically mobile-first, but not max-width: Mobile first, from a coding perspective, means that your base style is typically a single-column, fully-fluid layout. You use @media (min-width: whatever) to add a grid-based layout on top of that. from: http://gomakethings.com/mobile-first-and-internet-explorer/ EDIT: So to be more specific: I was wondering if there is a reason to exclude max-width from a mobile-first responsive design (as it seems like it can be useful for writing your css as DRY as possible, as some styles for small screens will not be used for bigger screens).

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• Design Book–Fourth(last) Section (Physical Abstraction Optimization)

  - by drsql

  In this last section of the book, we will shift focus to the physical abstraction layer optimization. By this I mean the little bits and pieces of the design that is specifically there for performance and are actually part of the relational engine (read: the part of the SQL Server experience that ideally is hidden from you completely, but in 2010 reality it isn’t quite so yet.  This includes all of the data structures like database, files, etc; the optimizer; some coding, etc. In my mind, this...(read more)

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• BizTalk host throttling &ndash; Singleton pattern and High database size

  - by S.E.R.

  Originally posted on: http://geekswithblogs.net/SERivas/archive/2013/06/30/biztalk-host-throttling-ndash-singleton-pattern-and-high-database-size.aspxI have worked for some days around the singleton pattern (for those unfamiliar with it, read this post by Victor Fehlberg) and have come across a few very interesting posts, among which one dealt with performance issues (here, also by Victor Fehlberg). Simply put: if you have an orchestration which implements the singleton pattern, then performances will continuously decrease as the orchestration receives and consumes messages, and that behavior is more obvious when the orchestration never ends (ie : it keeps looping and never terminates or completes). As I experienced the same kind of problem (actually I was alerted by SCOM, which told me that the host was being throttled because of High database size), I thought it would be a good idea to dig a little bit a see what happens deep inside BizTalk and thus understand the reasons for this behavior. NOTE: in this article, I will focus on this High database size throttling condition. I will try and work on the other conditions in some not too distant future… Test conditions The singleton orchestration For the purpose of this study, I have created the following orchestration, which is a very basic implementation of a singleton that piles up incoming messages, then does something else when a certain timeout has been reached without receiving another message: Throttling settings I have two distinct hosts : one that hosts the receive port (basic FILE port) : Ports_ReceiveHostone that hosts the orchestration : ProcessingHost In order to emphasize the throttling mechanism, I have modified the throttling settings for each of these hosts are as follows (all other parameters are set to the default value): [Throttling thresholds] Message count in database: 500 (default value : 50000) Evolution of performance counters when submitting messages Since we are investigating the High database size throttling condition, here are the performance counter that we should take a look at (all of them are in the BizTalk:Message Agent performance object): Database sizeHigh database sizeMessage delivery throttling stateMessage publishing throttling stateMessage delivery delay (ms)Message publishing delay (ms)Message delivery throttling state durationMessage publishing throttling state duration (If you are not used to Perfmon, I strongly recommend that you start using it right now: it is a wonderful tool that allows you to open the hood and see what is going on inside BizTalk – and other systems) Database size It is quite obvious that we will start by watching the database size and high database size counters, just to see when the first reaches the configured threshold (500) and when the second rings the alarm. NOTE : During this test I submitted 600 messages, one message at a time every 10ms to see the evolution of the counters we have previously selected. It might not show very well on this screenshot, but here is what happened: From 15:46:50 to 15:47:50, the database size for the Ports_ReceiveHost host (blue line) kept growing until it reached a maximum of 504.At 15:47:50, the high database size alert fires At first I was surprised by this result: why is it the database size of the receiving host that keeps growing since it is the processing host that piles up messages? Actually, it makes total sense. This counter measures the size of the database queue that is being filled by the host, not consumed. Therefore, the high database size alert is raised on the host that fills the queue: Ports_ReceiveHost. More information is available on the Public MPWiki page. Now, looking at the Message publishing throttling state for the receiving host (green line), we can see that a throttling condition has been reached at 15:47:50: We can also see that the Message publishing delay(ms) (blue line) has begun growing slowly from this point. All of this explains why performances keep decreasing when a singleton keeps processing new messages: the database size grows and when it has exceeded the Message count in database threshold, the host is throttled and the publishing delay keeps increasing. Digging further So, what happens to the database queue then? Is it flushed some day or does it keep growing and growing indefinitely? The real question being: will the host be throttled forever because of this singleton? To answer this question, I set the Message count in database threshold to 20 (this value is very low in order not to wait for too long, otherwise I certainly would have fallen asleep in front of my screen) and I submitted 30 messages. The test was started at 18:26. At 18:56 (ie : exactly 30min later) the throttling was stopped and the database size was divided by 2. 30 min later again, the database size had dropped to almost zero: I guess I’ll have to find some documentation and do some more testing before I sort this out! My guess is that some maintenance job is at work here, though I cannot tell which one Digging even further If we take a look at the Message delivery throttling state counter for the processing host, we can see that this host was also throttled during the submission of the 600 documents: The value for the counter was 1, meaning that Message delivery incoming rate for the host instance exceeds the Message delivery outgoing rate * the specified Rate overdrive factor (percent) value. We will see this another day… :) A last word Let’s end this article with a warning: DO NOT CHANGE THE THROTTLING SETTINGS LIGHTLY! The temptation can be great to just bypass throttling by setting very high values for each parameter (or zero in some cases, which simply disables throttling). Nevertheless, always keep in mind that this mechanism is here for a very good reason: prevent your BizTalk infrastructure from exploding!! So whatever you do with those settings, do a lot of testing and benchmarking!

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• Dealing with a fundamental design flaw when you're new to the project

  - by Matt Phillips

  I've just started working on an open source project with around 30 developers in it. I'm working on fixing some of the bugs as a way to get into the "loop" and become a regular committer to the project. The problem is I think I've uncovered a fundamental design flaw that's causing one of the bugs I'm working on. But I feel like if I blast this on the mailing list I'm going to come off as arrogant, and some of the discussions I've had about the issue are butting heads with some of the people. How should I go about this?

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• Challenges in multi-player Android Game Server with RESTful Nature

  - by Kush

  I'm working on an Android Game based on Contract Bridge, as a part of my college Summer Internship project. The game will be multi-player such that 4 Android devices can play it, so there's no BOT or CPU player to be developed. At the time of getting project, I realized that most of the students had already worked on the project but none of their works is reusable now (for variety of reasons like, undocumented code and design architecture, different platform implementation). I have experience working on several open source projects and hence I emphasis to work out on this project such that components I make become reusable as much as possible. Now, as the game is multi-player and entire game progress will be handled on server, I'm currently working on Server's design, since I wanted to make game server reusable such that any client platform can use it, I was previously confused in selecting Socket or REST for Game Server's design, but later finalized to work on REST APIs for the server. Now, since I have to keep all players in-sync while they make movements in game, on server I've planned to use Database which will keep all players' progress, specific for each table (in Bridge, 4 players play on single table, and server will handle many such game tables). I don't know if its an appropriate decision to use database as shared medium to track progress of each game table (let me know if there's an appropriate or better option). Obviously, when game is completed for the table, data for that table on server's database is discarded. Now the problem is that, access to REST service is an HTTP call, so as long as client doesn't make any request, server will remain idle, and consider a situation where A player has played a card on his device and the device requests to apply this change on the server. Now, I need to let rest of the three devices know that the player has played a card, and also update view on their device. AFAIK, REST cannot provide a sort-of Push-notification system, since the connection to the server is not persistent. One solution that I thought was to make each device constantly poll the server for any change (like every 56 ms) and when changes are found, reflect it on the device. But I feel this is not an elegant way, as every HTTP request is expensive. (and I choose REST to make game play experience robust since, a mobile device tends to get disconnected from Internet, and if there's Socket-like persistent connection then entire game progress is subject to lost. Also, portability on client-end is important) Also, imagining a situation where 10 game tables are in progress and 40 players are playing, a server must be capable to handle flooded HTTP requests from all the devices which make it every 56 ms. So I wonder if the situation is assumed as DoS attack. So, explaining the situation, am I going on the right track for the server design? I wanted to be sure before I proceed much further with the code.

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