Fwd: MySQL Newsletter: January 2003
Hans Zaunere
hans at nyphp.org
Mon Jan 27 10:38:39 EST 2003
I'm not sure how many people are aware of MySQL's newsletter, but I always
find it useful. It's also online at http://www.mysql.com/newsletter/ and
includes a great article on query caches and new features in MySQL 4
Hans
--- MySQL AB <newsletter at mysql.com> wrote:
> Date: Mon, 27 Jan 2003 05:11:24 +0100
> To: hans at nyphp.org
> Subject: MySQL Newsletter: January 2003
> From: MySQL AB <newsletter at mysql.com>
>
> MySQL Newsletter
> January 2003
> newsletter at mysql.com
>
> --------------------------------------------------
>
> Welcome to MySQL Newsletter
>
> MySQL Newsletter is a convenient channel in keeping you
> informed of the latest MySQL news. MySQL newsletter
> is sent only to those, who have opted-in to receive
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> Personalized Newsletter
>
> The newsletter you are reading is prepared specially
> for you based on the categories you have chosen to
> receive in your profile. This might mean that there
> are actually more articles in the full newsletter.
> You can read the full newsletter on our website at
> http://www.mysql.com/newsletter/2003-01/
>
> Articles in this newsletter:
>
> PRODUCTS
> * MySQL 4.0.9 (Gamma) is released
> * MyODBC 3.51.05 (gamma) is released
> * MySQL 3.23.55 is released
> FEATURES
> * Tuning MySQL Server 4.0 Query cache.
> TRAINING
> * Upcoming MySQL Training courses
> PARTNER CORNER
> * The Kompany partners with MySQL AB to offer Rekall Pro for MySQL
> LATEST NEWS
> * Latest MySQL News
>
> --------------------------------------------------
> PRODUCTS
>
> MySQL 4.0.9 (Gamma) is released
>
> MySQL 4.0.9, a new version of the world's most
> popular Open Source Database, has been released.
> It is now available in source and binary form for
> a number of platforms from our download pages at
> http://www.mysql.com/downloads/
> and mirror sites.
>
> Note that all mirrors may not be up to date; If
> you can't find this version on some mirror, please
> retry later or try another mirror.
>
> This is a new gamma release, fixing some recently
> discovered bugs.
>
> You can see the changes for 4.0.9 at the changelog
> at
> http://www.mysql.com/doc/en/News-4.0.9.html
>
> MyODBC 3.51.05 (gamma) is released
>
> As you might have already noticed from our web
> site, the MyODBC 3.51.05 - Gamma is released. It
> is now available in source and binary form for a
> number of platforms from our download pages at
> http://www.mysql.com/downloads/api-myodbc-3.51.html
>
> and mirror sites.
>
> This is the gamma release of MyODBC 3.51.05. This
> should be the final release in the development
> series before making the stable announcement
> unless if there is any critical bugs from this
> version.
>
> OpenOffice users must upgrade to this version on
> all platforms, as this
> includes number of fixes, and this version is
> pre-tested from the Open
> Office team before the release.
>
> So, please test this, and let us know the status
> back.
>
> Here is the list of changes:
>
> -- Fix for the thread-safe library core dumps when
> the driver is built with the debug options.
> -- Fix for OpenOffice to return valid list of
> catalog names SQLTables along with a valid catalog
> name.
> -- Fixed SQLTablePrivileges and
> SQLColumnPrivileges to return each
> privilege type in a individual rows.
> -- Fixed the time conversion format error from
> SQL_TIME_STRUCT.
> (Thanks to Ocke Janssen <ocke.janssen at sun.com> for
> the above 3 bugs from OpenOffice team).
> -- Fixed SQLSpecialColumns coredump on HP-UX
> (threaded library)
> -- Fixed SQLGetTypeInfo to return individual rows
> for auto_increment
> status for all numeric types. (Request from Gerry
> Sweeney <gerry at support-works.com>)
> -- Fixed to return an error when the conversion is
> from SQL_C_NUMERIC as the driver is not capable to
> handle SQL_NUMERIC_STRUCT conversion due to lack
> of descriptors support. (Request from Michael
> Thomas <mithomas at microsoft.com> from Microsoft
> ODBC team)
> -- Added missed ROWS_FETCH_PTR status to SQLFetch
> and SQLExtendedFetch as that of SQLFetchScroll
> along with PARAMS_PROCESSED_PTR.
> -- Fixed to not to set the default attributes for
> the new DSN when the attributes are set through
> the config APIs (Windows specific).
> -- Added to return the DRIVER name when there is
> no DSN is specified (Unix only fix).
> -- Support for the new autoconf tools along with
> few new configuration
> options.
> -- Lot of cleanups to configure script to work on
> all Unix platforms
> along with gcc 3.x compatibility.
> -- Added distribution utility scripts under
> scripts sub-directory.
> * Binary distribution support for all platforms
> * Snapshot source distribution
> -- Minor fix-ups to work with native compilers.
>
> Recommended upgrade to earlier versions on all
> platforms.
>
> For more information about MyODBC 3.51.05, refer
> to the following
> (updated):
>
> FAQ :
> http://www.mysql.com/products/myodbc/faq_toc.html
>
> (updated with new style, with a split on
> individual chapters).
> Manual :
> http://www.mysql.com/products/myodbc/manual_toc.html
>
> Release notes, Changelog and downloads:
> http://www.mysql.com/downloads/api-myodbc-3.51.html
>
>
>
> MySQL 3.23.55 is released
>
> MySQL 3.23.55, a new version of the popular Open
> Source Database, has been released. It is now
> available in source and binary form for a number
> of platforms from our download pages at
> http://www.mysql.com/downloads/
> and mirror sites.
>
> Note that not all mirror sites may be up to date
> at this point of time - if you can't find this
> version on some mirror, please try again later or
> choose another download site.
>
> This is a bugfix release for the current stable
> tree. Users who use MySQL in an untrusted
> multi-user environment should consider upgrading
> to this version, which also fixes a bug that
> enabled valid local users to crash mysqld by using
> a specially modified mysql client application.
>
> You can see the changes for 3.23.55 at the
> changelog at
> http://www.mysql.com/doc/en/News-3.23.55.html
>
> --------------------------------------------------
> FEATURES
>
> Tuning MySQL Server 4.0 Query cache.
>
> Peter Zaitsev
>
> It is always a challenging job to tune database
> for the best performance. There are plenty of
> options, which you can set to provide the balance,
> which provides the best performance for exactly
> your application. MySQL 4.0 adds more tools to
> this job by introducing Query Cache, which can
> also be tuned.
>
> What is the MySQL Query Cache?
> Query Cache is an intelligent MySQL feature, which
> allows to greatly improving the speed of the
> frequently executed queries by caching query
> response and returning it to the client instead of
> real query execution.
>
> In order to adjust Query Cache settings you need
> to understand how does the query cache work. Let
> us explain this briefly. As the query arrives to
> MySQL server it performs a textual comparison with
> the queries in the Query Cache. This means "SELECT
> * FROM a" and "Select * From a" will be recognized
> as different queries. If a query matches one
> stored in the cache, the cached result is
> returned. If not, then the query is executed and
> if parameters allow the query result is stored in
> the query cache. When a table is modified, queries
> stored in the cache using the modified table, are
> removed from query cache.
>
> There are 3 main variables, which can be used to
> tune Query Cache settings. They are
> query_cache_size, query_cache_limit and
> query_cache_type.
>
> query_cache_size:
> Setting proper query_cache_size is the most
> complex task. It sets the amount of memory used
> for the query cache. One should find the right
> balance between the benefit you get from query
> cache and that non-cached queries slow down a bit,
> basicly due to less amount of memory available for
> other caches and buffers. Only benchmarking can
> point out the exactly best balance, but there are
> some guidelines, how to set this variable. Basic
> idea is that the more benefit query cache
> potentially gives you, the more memory it might be
> worth to allocate for it. Qcache_inserts will show
> you how many queries are added to query cache
> while qcache_hits will show you how many query
> results are taken directly from the query cache
> instead of executing them. You should compare
> qcache_hits value to total number of your select
> queries to see what is your current hit rate. You
> may increase or degrease query_cache_size to find
> the value, which provides best performance for
> you. Note that as the query cache content gets
> invalidated with update queries, amount of memory
> which query cache can use is not unbound.
> Qcache_free_memory shows amount of free memory in
> query cache, which is not used at the moment. If
> this value stays constantly high during the load
> it might be good idea to decrease the query cache
> size, i.e. to free some memory from the query
> cache to other caches and buffers.
>
> query_cache_limit:
> This variable sets the maximum result size, which
> would be stored in the query cache. The reason to
> have this variable is to limit queries having very
> large result sets to overwrite all the queries in
> the query set. The way to set this variable is to
> determine, what is the largest result set size of
> the queries you wish to cache? In most cases you
> can find the answer easily. In some cases there
> are queries of any possible size. In such case you
> might want to compare benefit from caching this
> large query with benefit of having in the cache
> smaller queries, the large query overwrites to
> make the decision. Examining cache query hit rate
> is also a good help here. A rule of thumb to start
> tuning the parameter might be setting
> query_cache_limit 1/100 to 1/10 of
> query_cache_size.
>
> query_cache_type:
> There are two ways how query cache can be enabled.
> Setting this variable "on" will attempt to cache
> all select queries. It is a good setting if you do
> not want to make any changes in your application,
> but you want it to start using query cache. Thus
> this setting allows you later to mark queries you
> do not want to be cached with SQL_NO_CACHE.
> Setting query_cache_type value to "DEMAND" is a
> good solution if in your application most of the
> queries will not benefit from the caching, as they
> never repeat or result is invalidated before the
> query is repeated. With this option you can select
> those queries, which will benefit from caching by
> using the SQL_CACHE option.
>
> --------------------------------------------------
> TRAINING
>
> Upcoming MySQL Training courses
>
> MySQL AB is holding numerous training courses in
> the following countries: USA, Germany, Canada,
> France, UK, Australia, and Sweden. Check out dates
> and locations at
> http://www.mysql.com/training/
>
> --------------------------------------------------
> PARTNER CORNER
>
> The Kompany partners with MySQL AB to offer Rekall
> Pro for MySQL
>
> TheKompany provides a line of powerful,
> multi-platform tools for developers and desktop
> users, a number of which are database centric such
> as Rekall and DataArchitect, which is what led to
> this partnership. Rekall is a RAD DBMS centric
> tool for Linux, Windows and Mac OS X (to be
> released soon). Rekall provides a full compliment
> of widgets and tools for rapidly prototyping,
> creating and deploying applications on top of
> MySQL. Scripting on widgets and events is
> accomplished using the popular Python object
> oriented scripting language for which there is
> even an embedded debugger. DataArchitect is the
> emerging enterprise tool for designing databases,
> reverse engineering and creating ERD's, at all
> levels of an organization.
> Learn more and order at:
> http://www.thekompany.com/products/dataarchitect/
>
>
> --------------------------------------------------
> LATEST NEWS
>
> Latest MySQL News
>
> MySQL Adds Subselects, Upgrades Performance and
> Security
> http://www.mysql.com/press/release_2003_05.html
>
> MySQL AB Hosts First MySQL Users Conference &
> Expo
> http://www.mysql.com/press/release_2003_04.html
>
> MySQL Named "Swedish IT Product of the Year"
> http://www.mysql.com/press/release_2003_03.html
>
> MySQL Database Available on IBM eServer zSeries
> http://www.mysql.com/press/release_2003_02.html
>
> Enhanced MySQL Software for Mac OS X Available
> from MySQL AB
> http://www.mysql.com/press/release_2002_18.html
>
> Westone Amplifies Database Performance with
> MySQL
> http://www.mysql.com/press/user_stories/westone.html
>
> MySQL Releases Database Upgrade with Major
> Security, Stability Enhancements
> http://www.mysql.com/press/release_2002_17.html
>
> --------------------------------------------------
>
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>
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>
> ________________________________________________
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