Bug #74132 mysql_install_db takes much longer in 5.7.5

• Submitted: 29 Sep 2014 9:58
• Modified: 24 Nov 2014 16:34
• Reporter: Jorge Jordao
• Status: Closed
• Category: MySQL Server: Installing
• Severity: S2 (Serious)
• Version: 5.7.5
• OS: Any
• CPU Architecture: Any

[29 Sep 2014 9:58] Jorge Jordao

Description:
The mysql_install_db execution takes MUCH longer in 5.7.5 than in 5.7.4 (or 5.6.21).

The issue seems to originate not from the script/executable itself, but from the "mysqld --bootstrap" calls that it makes.

Results with a slightly modified mysql_install_db perl script that prints out elapsed times in seconds (find script attached):

$ scripts/mysql_install_db --no-defaults --basedir=/home/jorge/Temp/5.7.4 --datadir=/home/jorge/Temp/5.7.4/data --skip-random-passwords
Installing MySQL system tables...OK (9)
Filling help tables...OK (3)
Total time: 12

$ scripts/mysql_install_db --no-defaults --basedir=/home/jorge/Temp/5.7.5 --datadir=/home/jorge/Temp/5.7.5/data --skip-random-passwords
Installing MySQL system tables...OK (12)
Filling help tables...OK (102)
Total time: 114

How to repeat:
Run the attached mysql_install_db against a 5.7.4 and 5.7.5 installation.

[24 Nov 2014 16:34] Paul DuBois

Noted in 5.7.6 changelog.

With the change in MySQL 5.7.5 to InnoDB for the help tables in the
mysql database, mysql_install_db became much slower for loading the
help-table content. This was due to the INSERT statements loading
with autocommit enabled. Now all the statements execute as a single
transaction, not one transaction per statement.