I need to migrate some database from 5.0.37 to 5.7.11 to take advantage of Online DDL.
Before migration I wanted to do some performance testing. To test online DDL I generated a table with garbage data of 10 varchar columns and about 25 million records. I tried renaming column names on mysql 5.7 and it finishes instantly (5.0.37 took about 1 minute on same data). However creating indexes takes a long time on 5.7.11.
According to below documentation Index creation should happen fast and no table copying should occur. During Index creation disk usage is high so for some reason it is copying tables. Can anyone explain why this is not happening instantaneously like column renaming.
http://dev.mysql.com/doc/refman/5.7/en/innodb-create-index-overview.html#innodb-online-ddl-summary-grid
I have configured following variables as well
old_alter_table = 0
innodb_buffer_pool_size = 1G
innodb_log_file_size = 256M
Innodb_flush_log_at_trx_commit = 0
Before migration I wanted to do some performance testing. To test online DDL I generated a table with garbage data of 10 varchar columns and about 25 million records. I tried renaming column names on mysql 5.7 and it finishes instantly (5.0.37 took about 1 minute on same data). However creating indexes takes a long time on 5.7.11.
According to below documentation Index creation should happen fast and no table copying should occur. During Index creation disk usage is high so for some reason it is copying tables. Can anyone explain why this is not happening instantaneously like column renaming.
http://dev.mysql.com/doc/refman/5.7/en/innodb-create-index-overview.html#innodb-online-ddl-summary-grid
I have configured following variables as well
old_alter_table = 0
innodb_buffer_pool_size = 1G
innodb_log_file_size = 256M
Innodb_flush_log_at_trx_commit = 0
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