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Displaying posts with tag: innodb (reset)
Fun with Bugs #81 - On MySQL Bug Reports I am Subscribed to, Part XVII

Two weeks passed since my previous review of public MySQL bug reports I consider interesting enough to subscribe to them. Over this period I picked up a dozen or so new public bug reports that I'd like to briefly review today.

Here is my recent subscriptions list, starting from the oldest bug reports:

  • Bug #94431 - "Can't upgrade from 5.7 to 8.0 if any database have a hyphen in their name". It seems one actually needs a database like that created in MySQL 5.6 with at least one InnoDB table having FULLTEXT index to hit the problem. Great finding by Phil Murray. Note that after several unsuccessful attempts by others the bug was eventually reproduced and verified by …
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Percona XtraBackup 8.0.5 Is Now Available

Percona is glad to announce the release of Percona XtraBackup 8.0.5 on March 4, 2019. Downloads are available from our download site and from apt and yum repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an open source solution, it drives down backup costs while …

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Presentation : JSON improvements in MySQL 8.0

MySQL User camp is one of the prestigious MySQL meetup happening in India for the past 6 years. Mydbops DBA’s PonSuresh and Vignesh has presented about the “JSON functions and their improvements in MySQL 8.0” at MySQL User Camp Bangalore on 13-02-2019.

JSON has been more improved a lot in MySQL 8.0 and improvements in LOB storage of MySQL boost it performance further. This presentation covers the JSON performance enhancements in MySQL 8.0 with its basic functions.

JSON improvements in MySQL 8.0 from Mydbops

Fun with Bugs #80 - On MySQL Bug Reports I am Subscribed to, Part XVI

Today I'd like to continue my review of public MySQL bug reports with a list of some bugs I've subscribed to over last 3 weeks. It's already long enough and includes nice cases to check and share. Note that I usually subscribe to a bug either because it directly affects me or customers I work with, or I consider it technically interesting (so I mostly care about InnoDB, replication, partitioning and optimizer bugs), or it's a "metabug" - a problem in the way public bug report is handled by Oracle engineers. These are my interests related to MySQL bugs.

As usual, I start with the oldest bugs and try to mention bug reporters by name with links to their other reports whenever this may give something useful to a reader. I try …

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Fun with Bugs #79 - On MySQL Bug Reports I am Subscribed to, Part XV

More than 3 weeks passed since my previous review of public MySQL bug reports I am subscribed to, so it's time to present some of the bugs I've considered interesting in January, 2019.

As usual, I'll review them starting from the oldest and try to summarize my feelings about these bugs at the end of this post. Here they are:

  • Bug #93806 - "Document error about ON DUPLICATE KEY UPDATE". Years pass, but fine MySQL manual still does not explain some cases of InnoDB locking properly. Xiaobin Lin found yet another case that it does not explain properly. Or, maybe, the manual is correct and the problem in …
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Summary – Mydbops Database meetup 2

Mydbops database meetup was held on 26-01-2019 and 48 members from open source database community has attended this event. We had talks on MySQL and MongoDB databases.

Open source database enthusiastic from companies like OLA Cabs, Searce Inc, PayTm, Quikr, Zensar, Grab, SAP labs, Travel Yarri, Meddiff and a few has travelled from other cities of India like Hyderabad and Chennai.

The Welcome talk was given my Selva venkatesh of Mydbops. He spoke about the open source database community and welcomed all the participants and speakers.

Followed by it Karthik P R , CEO/ Founder, Mydbops made his presentation on “InnoDB Performance Optimisation” . InnoDB is the prime engine in MySQL.This talk focuses on the InnoDB Architecture in MySQL 8.0 and its fine tuning. He also answered the various questions raised …

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Compression Options in MySQL (Part 2)

In one of my previous posts, I started a series on data compression options with MySQL. The first post focused on the more traditional compression options like InnoDB Barracuda page compression and MyISAM packing. With this second part, I’ll discuss a newer compression option, InnoDB transparent page compression with punch holes available since 5.7. First, I’ll describe the transparent page compression method and how it works. Then I’ll present similar results as in the first post.

InnoDB transparent page compression

Before we can discuss transparent page compression, we must understand how InnoDB accesses its data pages. To access an InnoDB page, you need to know the tablespace (the file) and the offset of the page within the …

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Reduce MySQL Core Dump Size by Excluding the InnoDB Buffer Pool


When things go horrible wrong and a process crashes, one of the most powerful things to investigate the cause of the crash is a core dump. As the amount of memory allocated to processes such as MySQL has increased – in some cases approaching 1TiB of memory – enabling core dumps can cause problems of their own. MySQL Server 8.0.14 and later supports an option to reduce the size of the core dump which will be discussed in this blog.

Typically the largest single user of memory for MySQL is the InnoDB buffer pool. This is used to cache the data and indexes for tables using the InnoDB storage engine (the default). It is rarely important to know what is stored in the InnoDB buffer pool when investigating a crash, so a good way to …

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How to Switch Replica Master of a non-GTID Slave in Percona Cluster ?

Introduction –

Recently i worked on a production issue for one of our client under support .They have a architecture of a three node Galera cluster with one asynchronous slave .

  • Node1 –
  • Node2 –
  • Node3 –
  • Replica –

Architecture –

The slave(replica) was configured with node3 as replica master. Unfortunately the node 3 was crashed with an OOM killer ,also server has a low gcache size, so when i am trying to start the node 3 , it went to SST . Here the data size was around 2.6 TB , in general for completion of whole SST and joining the node back to cluster will take around  approximately 12 hours.

As i told earlier, the replication slave was under …

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ProxySQL Series: MySQL InnoDB Cluster balancing ( using config file )

Introduction –

                     At Mydbops we are exploring the latest MySQL technologies . Recently i was worked for one of our client the project. The requirement is setting up a three node InnoDB cluster with 3 node ProxySQL cluster . During my ProxySQL configuration, i discovered that the ProxySQL group replication host groups are not loading from ProxySQL config file . Then i reached the ProxySQL official website and found that they are already have the bug for this issue and provided the fix as well ( BUG #1050 ). The fixed version is ProxySQL 1.4.9 .

                   I just had the interest to write the blog about this behaviour, as …

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