Re: atomicity - Mailing list pgsql-general

Good Day All,

On Wed, 2002-02-27 at 01:28, Jean-Michel POURE wrote:
> > Is it true that the current version of PostgreSQL does always respect
> > atomicity of transactions and MySQL does not?

  The latest version of MySQL provides the option of supporting
  ACID-compliant transactions and row-level locking

> MySQL only supports transactions on INNODB tables. Therefore if your
> transactions includes other tables, we doubt atomicity works. Note this might
> change with MySQL 4.1.

  MySQL supports transactions with InnoDB tables and DBD tables. Users
  are provided with the choice of two different transactional table
  types and two non-transactional table types - one file-based (MyISAM),
  one memory-based (HEAP). The MySQL manual details this information.

  Users can choose the table type that best suits their needs.

> PostgreSQL offers the ability to build "intelligent" database with
> server-side programming (PLperl, PLpgSQL, ..), triggers, rules, views,
> operators... It is a real development tool.

  I agree that PostgreSQL is a good development tool that has features
  that MySQL does not yet possess (or that are more convenient to use in
  PostgreSQL than MySQL).

  I also believe that other databases, including MySQL are 'real'
  development tools.

> In a complex environment, PostgreSQL can be optimized at ***software level***
> (i.e. the way you build the database and program is server-side). MySQL can
> only be optimized at ***OS level*** or ***Harware level***.
>
> OS and Hardware level optimization can speed up an application by a factor of
> 2. Software optimization has no limit other than your imagination.

  This is an incorrect characterization of MySQL. Users have great
  control over the behavior of queries and the behavior of databases.
  These include options like delayed inserts, memory-stored indexes,
  packed indexes for faster index reading, hash-based tables stored in
  memory, read-efficient read-only databases, database replication, User
  Defined Functions, etc.

> On the converse, MySQL is just an "dumb" database only running simple SQL

  MySQL has a large, well-tested feature set that includes fewer
  traditional RDBMS features that PostgreSQL. PostgreSQL and MySQL come
  from very different traditions. PostgreSQL is the heir to quite
  phenonmenal amounts of academic research work that focused on
  developing a complete set of RDBMS features. MySQL evolved from a set
  of working development tools - it was developed with attention to
  speed, stability and performance at the cost of certain features.

  As PostgreSQL works to become a more practical development tool that
  requires less maintenance and is more robust, MySQL works towards
  having a larger set of features that are as robust as the current set.

> queries. Furthermore, it has very poor ODBC support and will only work in an

  To be specific, MySQL supports ODBC levels 0-3.51 - which is more than
  PostgreSQL supported last time that I checked.

> Apache environment.

  This is incorrect. In addition to the source, we distribute binaries
  for the following platforms:

  - Linux
  - Windows 95/98/NT/2000/XP
  - Solaris
  - FreeBSD
  - MacOS X
  - HP-UX
  - AIX
  - SGI Irix
  - Dec OSF

> If you are new to PostgreSQL, maybe the best thing to do is play with it
> using pgAdmin2 GUI, which can be found at http://pgadmin.postgresql.org.
  I would strongly consider reading Bruce Momjian's excellent book
  (See http://www.ca.postgresql.org/docs/awbook.html)


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