Re: > Subject: Re: Detailed explanation why uber move from postgress to mysql

From: Mladen Gogala <>
Date: Fri, 23 Dec 2016 22:54:29 -0500
Message-ID: <>

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:

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

Received on Sat Dec 24 2016 - 04:54:29 CET

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