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Percona Toolkit - Duplicate key checker

Optimistic Locking in MySql

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describe tablename;

Let's see if I can remember it this time thanks to this answer from RandomSeed

Was testing a change to some transaction handling and was confused at the results. Turns out the random table I chose to test with was MyISAM instead of Innodb.

But now I know how to setup general query logging and slow query logging on MariaDb and Mysql on a mac.

I had to use some help from: ewalshe and Drew on how to locate my.cnf on a mac.
It ended up being in
/usr/local/etc/my.cnf
The config added:
[mysqld]
general-log
general-log-file=queries.log
log-output=file
slow_query_log=1

If you installed with homebrew, you'll have to restart the service with:
brew services stop mariadb; brew services start mariadb
Using the restart target won't work.

Can then tail those logs:
tail -f /usr/local/var/mysql/myhostname.* /usr/local/var/mysql/queries.log
Change myhostname as appropriate. Best to just do an ls in that dir.

The format of the general query log was interesting too as it wasn't straightforward that the id referenced a thread for the database

What's in the slow query log: MariaDb docs

As a bonus, some Isolation Level Docs for MariaDb

This is great for making daily backups of your database, so that you can roll back to a known config.

Install
Use homebrew to install it.
brew install automysqlbackup

The config file is in /usr/local/etc/automysqlbackup/automysqlbackup.conf
You'll want to modify the excludes line to contain the following:
CONFIG_db_exclude=( 'information_schema' 'performance_schema' 'mysql')

create the directory /usr/local/var/backup:
mkdir -p /usr/local/var/backup

Usage
You can run manually with:
automysqlbackup

The databases should be saved to
cd /usr/local/var/backup/db
Optional: The "tree" command can be useful exploring that directory at the command line. You might need to install it via brew as well.

Generally, you can load those backups by first unzipping:
gunzip mydb_2018_04-04_10h00m.Friday.sql.gz

and then you can load it:
mysql < mydb_2018_04-04_10h00m.Friday.sql
or, with a password:
mysql -u myusername --password=THE_PASSWORD_GOES_HERE < mydb_2018_04-04_10h00m.Friday.sql

If the database already exists, you'll need to remove it.

Scheduling
Verify it is loaded in the mac scheduler with:
launchctl list | grep homebrew
Macs don't really use cron. They favor launchctl.

If it isn't there, you may need to copy:
cp /usr/local/Cellar/automysqlbackup/3.0-rc6/homebrew.mxcl.automysqlbackup.plist ~/Library/LaunchAgents
and then
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.automysqlbackup.plist

Big Deletes by Rick James

Mysql Internal Locking

View processes locking tables in Mysql

Create temporary tables in mysql

Getting the disk size of a table in mysql

Specifying index to use for a query in mysql

Interpreting Explain Query output in mysql

Performing online updates with mysql

From stackoverflow

Boils down to adding a couple of Java switches to the start script:
-Dswing.plaf.metal.controlFont=Tahoma-18 -Dswing.plaf.metal.userFont=Tahoma-18

For example, in squirrel-sql.sh, modify this line to include the above:
$JAVACMD -Xmx256m -Dswing.plaf.metal.controlFont=Tahoma-24 -Dswing.plaf.metal.userFont=Tahoma-24 -cp "$TMP_CP" $MACOSX_SQUIRREL_PROPS -splash:icons/splash.jpg net.sourceforge.squirrel_sql.client.Main --log-config-file "$UNIX_STYLE_HOME"/log4j.properties --squirrel-home "$UNIX_STYLE_HOME" $NATIVE_LAF_PROP $SCRIPT_ARGS

Link is a little older, but looks interesting: From enterprisedb.com

Postgres stores time in UTC, if you want to see the value of a date for a particular timezone, use one of the following:

SELECT now() AT TIME ZONE current_setting('TimeZone');
SELECT now() AT TIME ZONE 'EST5EDT';
SELECT now() AT TIME ZONE 'UTC';

From David Larochelle's blog

You can use:
COPY TABLE_NAME TO STDOUT WITH CSV HEADER
to push the output to a csv file.

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