From: Martin Gainty
Date: May 22 2009 5:23pm
Subject: RE: Question about Maria readers/writers
List-Archive: http://lists.mysql.com/mysql/217650
Message-Id: <BLU142-W128EFF3895DB5EEF6D3F47AE560@phx.gbl>
MIME-Version: 1.0
Content-Type: multipart/alternative;
	boundary="_225774c2-a17d-4ae5-9e81-2f685d0ce692_"

--_225774c2-a17d-4ae5-9e81-2f685d0ce692_
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable


only if you are implementing INNODB Transactional Storage Engine

MySQL uses table-level locking for MyISAM=2C
        MEMORY and MERGE tables=2C
        page-level locking for BDB tables=2C and
        row-level locking for InnoDB tables.
     =20
http://dev.mysql.com/doc/refman/5.0/en/internal-locking.html

Martin=20
______________________________________________=20
Verzicht und Vertraulichkeitanmerkung/Note de d=E9ni et de confidentialit=
=E9
=20
Diese Nachricht ist vertraulich. Sollten Sie nicht der vorgesehene Empfaeng=
er sein=2C so bitten wir hoeflich um eine Mitteilung. Jede unbefugte Weiter=
leitung oder Fertigung einer Kopie ist unzulaessig. Diese Nachricht dient l=
ediglich dem Austausch von Informationen und entfaltet keine rechtliche Bin=
dungswirkung. Aufgrund der leichten Manipulierbarkeit von E-Mails koennen w=
ir keine Haftung fuer den Inhalt uebernehmen.
Ce message est confidentiel et peut =EAtre privil=E9gi=E9. Si vous n'=EAtes=
 pas le destinataire pr=E9vu=2C nous te demandons avec bont=E9 que pour sat=
isfaire informez l'exp=E9diteur. N'importe quelle diffusion non autoris=E9e=
 ou la copie de ceci est interdite. Ce message sert =E0 l'information seule=
ment et n'aura pas n'importe quel effet l=E9galement obligatoire. =C9tant d=
onn=E9 que les email peuvent facilement =EAtre sujets =E0 la manipulation=
=2C nous ne pouvons accepter aucune responsabilit=E9 pour le contenu fourni=
.




> Date: Fri=2C 22 May 2009 09:32:02 -0500
> To: mysql@stripped
> From: mos99@stripped
> Subject: Question about Maria readers/writers
>=20
>  From the MySQL v6 manual:
> http://dev.mysql.com/doc/refman/6.0/en/se-maria-concurrency.html
>=20
> +++++
> When using transactional tables=2C Maria supports a single writer and=20
> multiple readers. The single writer supports both=20
> <http://dev.mysql.com/doc/refman/6.0/en/insert.html>INSERT and=20
> <http://dev.mysql.com/doc/refman/6.0/en/update.html>UPDATE operations.
>=20
> SELECT
>=20
> All issued SELECT's are running concurrently. While a SELECT is running=
=2C=20
> all writers (INSERT=2C DELETE=2C UPDATE) are blocked from using any of th=
e used=20
> tables (ie=2C they wait for the table to be free before continuing).
> +++++
>=20
> If it does support a single writer and multiple readers=2C why are the=20
> writers blocked when a Select is running? Shouldn't a single writer be ab=
le=20
> to run with concurrent Selects?
>=20
> Mike=20
>=20
>=20
> --=20
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe:    http://lists.mysql.com/mysql?unsub=3Dmgainty@stripped=
om
>=20

_________________________________________________________________
Hotmail=AE goes with you.=20
http://windowslive.com/Tutorial/Hotmail/Mobile?ocid=3DTXT_TAGLM_WL_HM_Tutor=
ial_Mobile1_052009=

--_225774c2-a17d-4ae5-9e81-2f685d0ce692_--