Re[2]: > Subject: Re: Detailed explanation why uber move from postgress to mysql
Date: Sat, 24 Dec 2016 17:15:08 +0300
Message-ID: <1482588908.201317556_at_f26.my.com>
Friday, December 23, 2016, 8:54 PM -0700 from Mladen Gogala <gogala.mladen_at_gmail.com>:
>On 12/23/2016 09:23 AM, Kellyn
Pot'Vin-Gorman wrote:
>>Uhm, MySQL has shard query, sharding technology in MySQL is
more advanced than Oracles to begin with...) and Heap tables, MySQL's older technology for memory tables has been around a significant amount of time. It's not apple for apples, but depending on the use case, MySQL has the features.
>>
>>Kellyn
>Hi Kellyn,
>In memory technology maintains columnar store in memory, together
with row store. The nett effect is as if a bitmap index is created
and maintained on the columns, minus the locking problem. This
advanced algorithm can speed up aggregated functions like avg, sum
or stddev functions tremendously. I have been using ENGINE=MEMORY
tables a long time ago, by creating a "sales" database from Oracle
on the nightly basis. Oracle was doing the heavy "group by" lifting
and the results were inserted into a MySQL database using Perl
scripts. Sales people were then accessing it using Crystal Reports
and Business Objects, two tools that used to create atrocious
queries against an Oracle database. The results were flying. I
don't, however, think that this could compete with the in-memory
technology employed by Oracle and other advanced commercial
databases. The first technology of that type was "BLU acceleration"
in DB2, a year older than Oracle's own in-memory option.
Interestingly enough, MySQL is entering the fray:
>
>http://www.infoworld.com/article/3150683/analytics/mariadb-crashes-open-souce-big-data-analytics-competitors.html
>
>MariaDB, an open source variety of MySQL has obviously developed
something very similar to Oracle's in-memory technology. Now, that
would be an excellent reason for moving from Postgres to MySQL.
>--
Mladen Gogala
Oracle DBA
>http://mgogala.freehostia.com
-- http://www.freelists.org/webpage/oracle-lReceived on Sat Dec 24 2016 - 15:15:08 CET