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Posts Tagged ‘Percona’

MariaDB MySQL Percona list all indexes without using INFORMATION_SCHEMA.STATISTICS

July 8, 2015 1 comment

There is nothing more to be said:

SELECT
gen.TABLE_SCHEMA
, gen.TABLE_NAME
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
) as COLUMN_NUM
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY != ""
) as INDEX_NUM_ALL
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "PRI"
) as INDEX_NUM_PRI
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "UNI"
) as INDEX_NUM_UNI
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "MUL"
) as INDEX_NUM_MUL

from information_schema.tables gen
where true
and gen.TABLE_SCHEMA !='mysql'
and gen.TABLE_SCHEMA!='performance_schema'
and gen.TABLE_SCHEMA!='information_schema'
;
+-----------------+-----------------------+------------+---------------+---------------+---------------+---------------+
| TABLE_SCHEMA | TABLE_NAME | COLUMN_NUM | INDEX_NUM_ALL | INDEX_NUM_PRI | INDEX_NUM_UNI | INDEX_NUM_MUL |
+-----------------+-----------------------+------------+---------------+---------------+---------------+---------------+
Categories: MariaDB, MySQL Tags: , , ,

MySQL, Percona, MariaDB long running processes clean up one liner

April 30, 2015 Leave a comment

There are tools like pt-kill from the percona tool kit that may print/kill the long running transactions at MariaDB, MySQL or at Percona data instances, but a lot of backup scripts are just some simple bash lines.
So checking for long running transactions before the backup to be executed seems to be a step that is missed a lot.

Here is one line that might be just added in every bash script before the backup to be executed
Variant 1. Just log all the processlist entries and calculate which ones were running longer than TIMELIMIT:

$ export TIMELIMIT=70 && echo "$(date) : check for long runnig queries start:" >> /tmp/processlist.list.to.kill && mysql -BN -e 'show processlist;' | tee -a /tmp/processlist.list.to.kill | awk -vlongtime=${TIMELIMIT} '($6>longtime){print "kill "$1";"}' | tee -a /tmp/processlist.list.to.kill

Variant 2: Log all the processlist, calculate the calculate which processes are running longer than TIMELIMIT, and kill them before to execute the backup:

$ export TIMELIMIT=70 && echo "$(date) : check for long runnig queries start:" >> /tmp/processlist.list.to.kill && mysql -BN -e 'show processlist;' | tee -a /tmp/processlist.list.to.kill | awk -vlongtime=${TIMELIMIT} '($6>longtime){print "kill "$1";"}' | tee -a /tmp/processlist.list.to.kill | mysql >> /tmp/processlist.list.to.kill 2>&1