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Displaying posts with tag: Internals (reset)
[Reprint]Injection MySQL – Function

Reprint a PDF for MySQL Injection Test

MySQL Error Based SQL Injection Using EXP

What Makes the MySQL Audit Plugin API Special?

Why Should I Be Reading This?

To better understand how the MySQL Server functions, how to monitor the relevant server events, and find out what’s new in MySQL 5.7.8.

What’s Special About the Audit Plugin API?

Picking the right API for your new plugin is probably the most important design decision a plugin author will need to make.…

How to configure Tcpdump system

MySQL Tcpdump system : use percona-toolkit to analyze network packages

We can identify problem SQLs with high execution frequency.

With DBMON system and AWR system we can find problem SQLs in a special time (high frequency, occurs over a period of time)

View this PDF:

http://www.vmcd.org/docs/MySQL_TCPDUMP.pdf

The InnoDB Change Buffer

One of the challenges in storage engine design is random I/O during a write operation. In InnoDB, a table will have one clustered index and zero or more secondary indexes.  Each of these indexes is a B-tree.  When a record is inserted into a table, the record is first inserted into clustered index and then into each of the secondary indexes.  So, the resulting I/O operation will be randomly distributed across the disk.  The I/O pattern is similarly random for update and delete operations. To mitigate this problem, the InnoDB storage engine uses a special data structure called the change buffer (previously known as the insert buffer, which is while you will see ibuf and IBUF used in various internal names).

The change buffer is another B-tree, with the ability to hold the record of any secondary index.  It is also …

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MariaDB : Bug when add index on Partition table

Version: 5.5.5-10.0.10-MariaDB-log MariaDB Server

When I use mariadb as multi-source slave DB I met a strange problem . Creating index on a vary large partition table , Mariadb do — copy to tmp table on the slave side. It takes a long time and still not finish over 9 hours.

Primary : MySQL 5.6.16 —

add index on a partition table:

CREATE TABLE `track_raw_wap211_log` (
 `table_id` varchar(100) DEFAULT NULL,
 `page_id` varchar(100) DEFAULT NULL,
 `banner_id` varchar(100) DEFAULT NULL,
 `button_id` varchar(100) DEFAULT NULL,
 `test_id` varchar(100) DEFAULT NULL,
 `classfication` varchar(100) DEFAULT NULL,
 `request_refer` varchar(100) DEFAULT NULL,
 `request_url` text,
 `title` varchar(100) DEFAULT NULL,
 `user_id` varchar(100) DEFAULT NULL,
 `language` varchar(100) DEFAULT NULL,
 `event` varchar(100) DEFAULT NULL,
 `event_desc` varchar(100) DEFAULT NULL,
 `event_type` varchar(100) DEFAULT NULL,
 `log_version` varchar(100) DEFAULT …
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Performance Impact of InnoDB Transaction Isolation Modes in MySQL 5.7

During the process of reviewing our server defaults for MySQL 5.7, we thought that it might be better to change the default transaction isolation level from REPEATABLE-READ to READ-COMMITTED (the default for PostgreSQL, Oracle, and SQL Server). After some benchmarking, however, it seems that we should stick with REPEATABLE-READ as the default for now.

It’s very easy to modify the default isolation level, however, and it can even be done at the SESSION level. For the most optimal performance you can change the transaction isolation level dynamically in your SESSION according …

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Extent Descriptor Page of InnoDB

Within the MySQL data directory, the InnoDB storage engine creates two types of files — the data files and the redo log files. Each data file (or ibd file) belongs to exactly one tablespace. Each tablespace is given a unique identifier called the space_id. One tablespace can have 1 or more data files. If a tablespace has more than one data file, then the data files have a specific order or sequence. The data files can be thought of as being concatenated to each other in that specific order.

The data file is made up of a series of equal sized pages. Each page in the data file is given a unique number identifier called the page number (page_no). The first page of the first ibd file is given the page_no of 0. The page number of the first page of the second ibd file of the tablespace is …

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Using the row buffer in Drizzle (and MySQL)

Here’s another bit of the API you may need to use in your storage engine (it also seems to be a rather unknown. I believe the only place where this has really been documented is ha_ndbcluster.cc, so here goes….

Drizzle (through inheritance from MySQL) has its own (in memory) row format (it could be said that it has several, but we’ll ignore that for the moment for sanity). This is used inside the server for a number of things. When writing a Storage Engine all you really need to know is that you’re expected to write these into your engine and return them from your engine.

The row buffer format itself is kind-of documented (in that it’s mentioned in the MySQL Internals documentation) but everywhere that’s …

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Building MySQL Server with CMake on Linux/Unix

CMake is a cross-platform, open-source build system, maintained by Kitware, Inc.

From the CMake.org home page:

CMake is a family of tools designed to build, test and package software. CMake is used to control the software compilation process using simple platform and compiler independent configuration files. CMake generates native makefiles and workspaces that can be used in the compiler environment of your choice.

It has been used for building the MySQL Server on Windows since MySQL 5.0 – the initial CMake build support was added in August 2006.

For …

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2010 will be a good year,

I suppose I should make it official: 2010 should see me being much more active in the Community.Why? Simply because I am now working for Blizzard Entertainment where I hope to help them make better, more efficient, use of MySQL/MariaDB. I expect to be working on some of MySQL's internals and storage engines in order to achieve what is wanted and helping them enhance their existing use of

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