maria-discuss team mailing list archive

[Roberto Spadim <roberto@xxxxxxxxxxxxx>]

SET innodb_table_locks=1; SET autocommit=0;
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
BEGIN;
INSERT INTO m VALUES (1);
INSERT INTO t VALUES (1);
SELECT @@in_transaction; <- return 1
UNLOCK TABLES;
SELECT @@in_transaction; <- return 1


------
SET innodb_table_locks=1; SET autocommit=0;
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
BEGIN;
SELECT @@in_transaction; <- return 1
lock table m write;
SELECT @@in_transaction; <- return 1
INSERT INTO m VALUES (1);
INSERT INTO t VALUES (1); /* Erro SQL (1100): Table 't' was not locked with
LOCK TABLES */
SELECT @@in_transaction; <- return 1
UNLOCK TABLES;
SELECT @@in_transaction; <- return 0




2014-09-22 20:46 GMT-03:00 Roberto Spadim <roberto@xxxxxxxxxxxxx>:

> well from kb what i understand is:
> to use unlock with innodb (the engine you use with both tables), you
> should SET innodb_table_locks=1; SET autocommit=0; after that any
> LOCK/UNLOCK with innodb tables inside a transaction will commit the
> transaction
>
> try again using innodb_table_locks, and autocommit variables
>
>
> 2014-09-22 19:51 GMT-03:00 Federico Razzoli <federico_raz@xxxxxxxx>:
>
> No, becuase the first test case I've posted shows that the reality is
>> different... :)
>> I'm just asking to explain the exact interaction between trx and UNLOCK,
>> because I need to know if statements I use are safe.
>>
>> Federico
>>
>>
>> --------------------------------------------
>> Mar 23/9/14, Roberto Spadim <roberto@xxxxxxxxxxxxx> ha scritto:
>>
>>  Oggetto: Re: [Maria-discuss] transactions and UNLOCK TABLES
>>  A: "Federico Razzoli" <federico_raz@xxxxxxxx>
>>  Cc: "Maria Discuss" <maria-discuss@xxxxxxxxxxxxxxxxxxx>, "maria-docs" <
>> maria-docs@xxxxxxxxxxxxxxxxxxx>
>>  Data: Martedì 23 settembre 2014, 00:14
>>
>>  better
>>  explained at mariadb kbhttps://
>> mariadb.com/kb/en/mariadb/documentation/sql-commands/transactions/lock-tables-and-unlock-tables/#limitations
>>  ​
>>
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>
>
>
> --
> Roberto Spadim
> SPAEmpresarial
> Eng. Automação e Controle
>



-- 
Roberto Spadim
SPAEmpresarial
Eng. Automação e Controle