Showing entries 61 to 70 of 137
« 10 Newer Entries | 10 Older Entries »
Displaying posts with tag: bugs (reset)
Fun with Bugs #8 - what's wrong with Oracle's way of handling public MySQL bugs database

Many people seem unhappy with the way Oracle develops MySQL. I am not one of them. I think very few really important things are missing and in this post I'd like to concentrate on one of them: having internal and public bugs databases not in sync in too many cases.

Let me quote myself to explain where problem starts:

"Now the most important thing you should know about MySQL bugs processing the way it is done now in Oracle. When bug is "Verified" and(!) considered serious enough, it is copied to the Oracle internal bugs database and further processing, including status changes etc, is done there. All further comments to the public bug report are then copied to internal bug report automatically, but no comments or status changes in internal bug report are copied to public bug in any other way …

[Read more]
MySQL bug 69179 – INFORMATION_SCHEMA.PARTITIONS causes query plan changes

Shard-Query examines INFORMATION_SCHEMA.PARTITIONS to determine if a table is partitioned.  When a table is partitioned, Shard-Query creates multiple background queries, each limited to a single partition.  Unfortunately, it seems that examining INFORMATION_SCHEMA.PARTITIONS causes query plans to change after the view is accessed.

I have reported bug 69179 to MySQL AB  Oracle Corporation(old habits die hard).

Be careful: If you have automated tools (like schema management GUI tools) then make sure they don’t examine INFORMATION_SCHEMA.PARTITIONS or you may get bad plans until you analyze your tables or restart the database, even if using persistent stats.

I can only get the bug to happen when a WHERE clause is issued that limits access to a single partition.  It may be that the per partition statistics …

[Read more]
Fun with bugs #7, still mostly about 5.6.11

It looks like now Oracle will release new 5.6.x every 2 months, so while I'd happily write about bugs fixed in 5.6.12 we still have to wait for the official release to happen. I am too impatient to wait for 5.6.12, so let me write this post of a classical kind - just a summary of my MySQL bugs' related posts on Facebook since the previous one.

I have to start with replication-related bugs in 5.6.11 pointed out by Giuseppe Maxia:

  • Bug #69095 -  replication fails with GTID enabled and master changes from SBR to RBR. This bug is "Verified" since April 30, but got no public comments since that. …
[Read more]
Fun with Bugs #6 - MySQL 5.6.11

Last time I had written about bugs here it was a beginning of February, and hardly somebody could imagine that we were going to have 2 more months of winter, 2 more months to wait for next MySQL 5.6 GA release or that in 2 months and two weeks I'll be speaking about MySQL in public for 50 minutes based on my own presentation, and speaking about bugs (surely)...

In any case, MySQL 5.6.11 looks promising and had got a lot of bugs fixes (check at least this nice post by Todd Farmer). Time for me to get back to bugs I've mentioned in the previous …

[Read more]
MySQL: Every detail matters

Some bugs can have a high impact if it causes data corruption, security issues or simply causes MySQL to crash. But what about small bugs and small usability issues?

This entry from the MySQL 5.6.8 release notes is an interesting one:
InnoDB: On startup, MySQL would not start if there was a mismatch between the value of the innodb_log_file_size configuration option and the actual size of the ib_logfile* files that make up the redo log. This behavior required manually removing the redo log files after changing the value of innodb_log_file_size. The fix causes MySQL to write all …

[Read more]
Granting privileges may break replication in MySQL 5.6.10

MySQL lets database administrators define access rights on many levels – from the ability to run global commands down to access to individual columns. Some rights can be applied to many different objects, such as for example SELECT or UPDATE, which can be granted globally or restricted only to certain databases or tables, while others are only meant for one specific purpose. An example of the latter could be FILE privilege, which permits user to interact with the file system from inside a database instance. It only makes sense as the global right and not anywhere else.

As any other activity that produces changes, GRANT statements are replicated to MySQL slaves. Regardless of the binary log format setting, such events are always logged in STATEMENT format. It is likely because the command needs to handle more than just updating the contents of a few system tables, so such design allows each slave to fully execute the changes within their …

[Read more]
17 Famous MySQL Bug Reporters

Every good bug report at http://bugs.mysql.com matters and may have important findings or useful information inside (even if it is declared as "Not a bug" or "Unsupported"), but based on my experience reports from some people should become a mandatory reading for both MySQL users who care about there servers, and Oracle engineers who process bugs.

Let me name a few of these people, "Top 17" of them based on my totally non-scientific, experience-based approach. You can click on the name to see the list of all bugs reported by this person, started from the recent ones (this may help to understand why I consider their input important).

  1. Shane Bester - 921 bug reports (feature requests excluded, as …
[Read more]
Fun with Bugs, Issue #5, February 2013

This week we had finally got MySQL 5.6.10 released as GA. It's a big deal, first MySQL GA release with the entire development process happened in Oracle from day one, quantum leap (as every second blog post says these days) in many areas, from scalability to replication performance, with InnoDB fulltext indexes and PERFORMANCE_SCHEMA improvements in between... So, this week it makes sense to concentrate on 5.6 GA and nothing else.

As one of my former colleagues noted, no GA is bug free. Surely there are known and verified bugs in 5.6.10, but not that many. Let me just give you a list to check, in case you plan to upgrade/switch to 5.6 in production:

Bug #68300 (crash when password expire is set for a user, in a corner case)
Bug #68299 (EXPLAIN output for …

[Read more]
Fun with Bugs, Issue #4, January 2013

This post will cover bugs I've "escalated" on Facebook during the period from January 28 till January 31. There were several serious bug reports noted, but many were taken from this great page that was created by Hartmut and updates every day. I had to find new source of fun, as Oracle reduced number of open and unassigned server bugs even more and processes new ones really fast this week. So, let's speak about some "Oldies but Goldies"...

I'd like to start with Bug #39489 ("In progress" for 2 years) from one of my former bosses, Dean. I've noted recently that I still can see private comments made by me in older  reports, so I know that I asked to fix this in 5.5, even if after GA. Discussion that happened …

[Read more]
Fun with Bugs, Issue #3, January 2013

This week in my posts on Facebook I paid attention mostly to bugs in MySQL 5.6.x, as I really expected to see 5.6 GA announcement soon. Maybe some of the bugs were the reason to postpone release a bit. Anyway, let's start with serious bug reports and some trends I've noted.

I've noted that some of "Verified" bug reports somehow silently miss comments about their status in MySQL 5.6. Check Bug #68137, for example. It is repeatable on 5.5.31 (yet to be released, but it means 5.5.30 is cloned off and will be released soon) and 5.7.1. But 5.6.x is not mentioned anywhere. Does it mean 5.6.x is not affected? Surely, no. I hope it does NOT mean any attempt by Oracle to pretend that 5.6 is bugs free. Looks like Sveta had just forgotten to check or report result on this version when following her …

[Read more]
Showing entries 61 to 70 of 137
« 10 Newer Entries | 10 Older Entries »