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Displaying posts with tag: acid (reset)

How to structure and design a relational database to support you data storage needs?
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Well, every now and then, when we began to start a new project or app, which has some data storage requirement, we have a deep intriguing thought as to how best represent the data structure so as to support a variety of needs including but not limited to (ACID rules):

1. Normalization
2. Reliability
3. Consistency
4. And many others

Below, I provide a set of steps which you can follow to arrive at a data model that correctly suites your requirements.

Steps:

1. Identify the project or app requirements / specifications and business rules which tell you what your app will be able to do when it is ready.
2. From these business rules, identify possible objects for each business rule and mark them in a paper using rectangular sections like authors,











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Slides from PLMCE 2014 breakout session
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As many of you already know, PLMCE is an annual MySQL
community conference and Expo organized by Percona in the month of April
(usually). It is a great conference, not only to meet new and eminent people in
MySQL and related database fields, but also to attend interesting talks, and
also to give some.

This year I spoke about synchronous replication at a higher level. The talk was
titled “ACIDic Clusters: Review of current relational databases with synchronous replication”. Having previously given talks with boring titles (but





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MySQL needs single master to check data integrity
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Read the original article at MySQL needs single master to check data integrity

MySQL slaves can drift out of sync. Many of our clients are surprised to find some data differences in their replication topology, once we do some checking and sniffing around. Such checks require a single reliable or authoritative master to compare against. Click through to the end for multi-master solutions that work with MySQL. Reason [...]

For more articles like these go to Sean Hull's Scalable Startups

Related posts:
  • MySQL requires an authoritative master to build slaves
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    On Eventual Consistency– Interview with Monty Widenius.
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    “For analytical things, eventual consistency is ok (as long as you can know after you have run them if they were consistent or not). For real world involving money or resources it’s not necessarily the case.” — Michael “Monty” Widenius. In a recent interview, I asked Justin Sheehy, Chief Technology Officer at Basho Technologies, maker [...]
    Differences between READ-COMMITTED and REPEATABLE-READ transaction isolation levels
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    As an instructor with Percona I’m sometimes asked about the differences between the READ COMMITTED and REPEATABLE READ transaction isolation levels.  There are a few differences between READ-COMMITTED and REPEATABLE-READ, and they are all related to locking.

    Extra locking (not gap locking)
    It is important to remember that InnoDB actually locks index entries, not rows. During the execution of a statement InnoDB must lock every entry in the index that it traverses to find the rows it is modifying. It must do this to prevent deadlocks and maintain the isolation level.

    If you run an UPDATE that is not well indexed you will lock many rows:

    update employees set store_id = 0 where store_id = 1;
    ---TRANSACTION 1EAB04, ACTIVE 7 sec
    633 lock struct(s), heap


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    Understanding InnoDB transaction isolation levels
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    Isolation is an important part of ACID properties that guarantee that transactions are processed in a reliable manner. But there are four different levels of isolation available and you have to understand each one of them to be able to select the correct one for your needs. This post intends on explaining the four levels together with their effects on locking and performance.
    Tuning InnoDB Configuration
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    I had earlier written a post on tuning the MySQL server configuration which was more geared towards the MyISAM storage engine. While that is not because I didn't intend on ignoring InnoDB but because I had planned a whole post on tuning InnoDB related configuration. So this post is the post that I had planned, I have discussed the major configuration parameters in here that should help you out most of the times.
    Dispelling some unintentional MySQL FUD
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    There are three types of FUD: the first and more genuine is (#1) the intentional spreading of falsehood, mostly to gain some marketing advantage over a competing product. While I despise this practice, I understand it.
    Then there is (#2) FUD spread by ignorance, when the originators are so blindly enraged by their hatred for a product that they don't care about getting the facts straight.
    And finally, there is a third kind, not less dangerous, which is (#3) the spreading of FUD with good intentions, when the authors believe that they have the facts straight and they want to help.I have recently come across two examples of

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    Why do I recommend switching over from MyISAM to Innodb!
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    Although MyISAM has been the default storage engine for MySQL but its soon going to change with the release of MySQL server 5.5. Not only that, more and more people are shifting over to the Innodb storage engine and the reasons for that is the tremendous benefits, not only in terms of performance, concurrency, ACID-transactions, foreign key constraints, but also because of the way it helps out the DBA with hot-backups support, automatic crash recovery and avoiding data inconsistencies which can prove to be a pain with MyISAM. In this article I try to hammer out the reasons why you should move on to using Innodb instead of MyISAM.
    Easy MySQL: transaction isolation and ACID, the simple explanation
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    Clients often ask what the differences are between the various InnoDB isolation levels, or what ACID means. Here are some simple explanations for those that have not yet read the manual and committed it to memory.

    READ UNCOMMITTED
    Every select operates without locks so you don’t get consistency and might have dirt reads, which are potentially earlier versions of data. So, no ACID support here.

    READ COMMITTED
    Has consistent reads without locks. Each consistent read, even within the same transaction, sets and reads its own fresh snapshot.

    REPEATABLE READ
    The InnoDB default isolation level for ACID compliance. All reads within the same transaction will be consistent between each other – ie, the C in ACID. All writes will be durable, etc etc.

    SERIALIZABLE
    Same as




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    Showing entries 1 to 10 of 15 5 Older Entries

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