Author - Nilnandan Joshi

Transporting tablespace from MySQL 5.6 to MySQL 5.7 (case study)

Recently, I was working on a MySQL support ticket where a customer was facing an issue while transporting tablespace from MySQL 5.6 to MySQL 5.7.
After closely reviewing the situation, I saw that while importing tablespace they were getting errors such as:

Shell

ERROR 1808 (HY000): Schema mismatch (Table flags don’t match, server table has 0x10 and the meta-data file has 0x1)

1

ERROR […]

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InnoDB locks and deadlocks with or without index for different isolation level

Recently, I was working on one of the issue related to locks and deadlocks with InnoDB tables and I found very interesting details about how InnoDB locks and deadlocks works with or without index for different Isolation levels.
Here, I would like to describe a small test case about how SELECT ..FOR UPDATE (with and without limit) behave […]

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How to log slow queries on Slave in MySQL 5.0 with pt-query-digest

Working as a Percona Support Engineer, every day we are seeing lots of issues related to MySQL replication. One very common issue is slave lagging. There are many reasons for slave lag but one common reason is that queries are taking more time on slave then master. How to check and log those long-running queries? […]

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How to monitor ALTER TABLE progress in MySQL

How to monitor ALTER TABLE progress in MySQL

While working on a recent support issue as a Percona Support Engineer,  I got one question from a customer asking how to monitor ALTER TABLE progress. Actually, for MySQL 5.5 and prior versions, it’s quite difficult to ALTER the table in a running production environment especially for large tables (with millions of records). Because it will […]

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MySQL server memory usage troubleshooting tips

MySQL Server Memory

There are many blog posts already written on topics related to “MySQL server memory usage,” but nevertheless there are some who still get confused when troubleshooting issues associated with memory usage for MySQL. As a Percona support engineer, I’m seeing many issues regularly related to heavy server loads – OR OOM killer got invoked […]

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