An old story that is not yet solve.

Why this article.

Some time ago I had open a bug report to codership through Seppo.

The report was about the delay existing in executing data load with FK. (https://bugs.launchpad.net/codership-mysql/+bug/1323765).

The delay I was reporting at that time were such to scare me a lot, but I know talking with Alex and Seppo that they were aware of the need to optimize the approach an some work was on going.

After some time I had done the test again with newer version of PXC and Galera library.

This article is describing what I have found, in the hope that share information is still worth something, nothing less nothing more.

The tests

Tests had being run on a VM with 8 cores 16GB RAM RAID10 (6 spindle 10KRPM).

I have run 4 types …

This is a maintenance release which contains mainly bugfixes.

Get it from the download page.



Changelog:
* Bugfix: Crash in foreign key dropdown editor
* Bugfix: Crash when killing processes on very long running servers
* Bugfix: SQL error when accessing UUID and JSON columns in PostgreSQL via SUBSTR
* Bugfix: MSSQL: Prefer "schema.table" quoting over "schema"."table" when renaming a table
* Bugfix: Fix column type converted to locale string format by String.ToUpper in TDBConnection.GetCreateCode - prefer String.ToUpperInvariant instead, to avoid funny characters in data types
* Bugfix: MSSQL: Do not pass "Database=xyz" to connection string if database(s) setting contains more than one …

This is a maintenance release which contains mainly bugfixes.

Get it from the download page.



Changelog:
* Bugfix: Crash in foreign key dropdown editor
* Bugfix: Crash when killing processes on very long running servers
* Bugfix: SQL error when accessing UUID and JSON columns in PostgreSQL via SUBSTR
* Bugfix: MSSQL: Prefer "schema.table" quoting over "schema"."table" when renaming a table
* Bugfix: Fix column type converted to locale string format by String.ToUpper in TDBConnection.GetCreateCode - prefer String.ToUpperInvariant instead, to avoid funny characters in data types
* Bugfix: MSSQL: Do not pass "Database=xyz" to connection string if database(s) setting contains more than …

MariaDB 10.1.6 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.1.6/

This is the 4th beta, and 7th overall, release of MariaDB 10.1. There were not many major changes in this release, but a few notable items, as well as many overall bugs fixed (I counted 156, down ~50% from 10.1.5).

Since it’s beta, I’ll only cover the major changes and additions, and omit covering general bug fixes (feel free to browse them all here).

To me, these are the highlights:

• RESET_MASTER is extended with TO # clause which allows one to specify the number of the first binary log. (MDEV-8469)
• Added support for …

MySQL 5.6.26 was recently released (it is the latest MySQL 5.6, is GA), and is available for download here.

For this release, there are 3 “Functionality Added or Changed” items, 1 “Security Fix”, and 36 other bug fixes.

Out of those other 36 bugs, 13 are InnoDB, 1 Partitioning, 3 Replication, and 19 misc. (including 3 potentially crashing bug fixes, and 1 performance-related fix) Here are the ones of note:

• Functionality Added/Changed: Replication: When using a multi-threaded slave, each worker thread has its own queue of transactions to process. In previous MySQL versions, STOP SLAVE waited for all workers to process their entire queue. This logic has been changed so that STOP SLAVE first finds the newest transaction that was committed by any worker thread. Then, it waits for all workers to complete …

VividCortex now lets you search for queries that cause a specific error in your application. The error code itself will be database-specific, but for example error 1062 in MySQL is a duplicate key error, and in PostgreSQL error 23503 is a foreign key violation.

One of our customers requested that we add this feature so they could search for queries that cause UTF8 issues, which is a great example of when this can be useful.

To use this feature, click on the Queries navigation link, which brings up a catalog of every query we have seen execute in your systems. At the top, select the drop-down menu and filter by errors, then type in the error code you’re looking for and click Apply:

The result will be a listing of all queries that cause the server to return that error (even if it’s only an occasional error).

You might be surprised at how many queries cause once-in-a-million errors! They’re really hard to find …

VividCortex now lets you search for queries that cause a specific error in your application. The error code itself will be database-specific, but for example error 1062 in MySQL is a duplicate key error, and in PostgreSQL error 23503 is a foreign key violation.

One of our customers requested that we add this feature so they could search for queries that cause UTF8 issues, which is a great example of when this can be useful.

To use this feature, click on the Queries navigation link, which brings up a catalog of every query we have seen execute in your systems. At the top, select the drop-down menu and filter by errors, then type in the error code you’re looking for and click Apply:

The result will be a listing of all queries that cause the server to return that error (even if it’s only an occasional error).

You might be surprised at how many queries cause once-in-a-million errors! They’re really hard to find …

Hi Keith 🙂

Thank you for the great write up. I am setting up a demo on raspberry pi 2, and the DemoKit you showed looks like fun. Please feel free to email me, if it is OK for me get a copy of DemoKit as well.

MySQL 5.5.45 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://dev.mysql.com/downloads/mysql/5.5.html

This release, similar to the last 5.5 release, is mostly uneventful.

There were 0 “Functionality Added or Changed” items this time, 1 “Security Fix”, and just 9 bugs overall fixed.

Out of the 9 bugs, there were 3 InnoDB bugs, 1 security-related bug, and 1 potential crashing bug. Here are the ones worth noting:

• InnoDB: An index record was not found on rollback due to inconsistencies in the purge_node_t structure.
• InnoDB: An assertion was raised when InnoDB attempted to dereference a NULL foreign key object.
• InnoDB: On Unix-like platforms, os_file_create_simple_no_error_handling_func and …

Introduction

A foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table. The table containing the foreign key is called the child table, and the table containing the candidate key is called the referenced or parent table. The purpose of the foreign key is to identify a particular row of the referenced table. Therefore, it is required that the foreign key is equal to the candidate key in some row of the primary table, or else have no value (the NULL value). This is called a referential integrity constraint between the two tables. Because violations of these constraints can be the source of many database problems, most database management systems provide mechanisms to ensure that every non-null foreign key corresponds to a row of the referenced table. Consider following simple example:

create table parent (
    id int not null primary key,
    name char(80)
) …