- developers - lists.mariadb.org

[Maria-developers] CREATE OR REPLACE DATABASE algorithm
by sriram patil 27 May '14

27 May '14

Hi Alexander and all, Following are the steps that I am following for implementing "CREATE OR REPLACE" for DATABASE "..." signifies, there exists one or more lines of code in that block of the function. mysql_create_db(...) ... ... if(db exists) { if(create_or_replace) { if(DROP_ACL access not granted) { // Error 1 DBUG_RETURN(-1) } if(mysql_rm_db(...) unsuccessful) { // Error 2 DBUG_RETURN(-1) } Reset m_status from diagnostics cause it is changed by mysql_rm_db. Proceed with normal create db. } else if(if not exists) { ... } else ... } ... ... } Is the above algorithm correct? Also, I am not yet sure which errors should be displayed at both the places "Error 1" and "Error 2". I have written and tested the above code. It is working fine. Testing involves running all the existing test cases and executing "CREATE OR REPLACE DATABASE" command on the console manually. "IF NOT EXISTS" gives error if used with "CREATE OR REPLACE". Any other test cases I need to consider? Thanks, Sriram

2 2

[Maria-developers] FOR JSON
by Alexander Barkov 26 May '14

26 May '14

Hello Monty, We discussed extracting data in JSON format today, to make it possible to return data as a single JSON value (as a result set consisting of a single row and a single column): SELECT id,name,address FROM users FOR JSON; Note, in some cases the result of a such query can obviously be very huge. So it would be nice to be able to use "FOR JSON" in subselects, like this: SELECT id, (SELECT name,address FROM users AS b WHERE a.id= b.id FOR JSON) AS RowJSON FROM users AS a; This query will return a result set with multiple rows (one row per one record) and with two columns: - the ID, as a regular number - the JSON value with "name" and "address" embedded into it. Or, another example, if one does not need "id" as a separate column: SELECT (SELECT id,name,address FROM users AS b WHERE a.id= b.id FOR JSON) AS RowJSON FROM users AS a; This query will return a result set with multiple rows (one row per one record) with a single JSON value embedding all three columns: "id", "name" and "address".

2 4

[Maria-developers] MariaDB 10.1 is now on github!
by Sergei Golubchik 26 May '14

26 May '14

Hi! I'm happy to announce that MariaDB-10.1 tree has been completely migrated to github. Since now on we'll use github for the new development in MariaDB. It's https://github.com/MariaDB/server, go on, fork it, hack around, submit pull requests. Have fun! Older trees (10.0, 5.5, 5.3, 5.2, 5.1) are not on github - we do hope to migrate them too eventually, but at the moment they are still on launchpad. If you're a maria-captain on launchpad - for you to get write access to the mariadb repository on github you need to tell me your github account name. Regards, Sergei P.S.: Don't forget that 10.1 is still *pre-alpha*. You've been warned.

4 5

Re: [Maria-developers] MariaDB 10.1 is now on github!
by Sergei Golubchik 26 May '14

26 May '14

Hi, Binod! First: please send questions like this to maria-developers(a)lists.launchpad.net it's a public mailing list dedicated to MySQL and MariaDB internals, source code, and related things. I am subscribed, so I'll see you mail there, and you may be sure I will, because it won't be accidentally catched by my spam filter, or sorted out in some obscure folder. Furthermore other subscribers will see your question and could reply if I will be not available (e.g. I could be travelling). Thank you. On May 26, Binod Bista wrote: > Hi Sergei, > > Thanks for the info. Just to interrupt, is there a page you recommend for > anyone starting out in MariaDB development? Particularly any database or > MySQL internals material that help understand the codebase. That depends on what you're trying to do. There are two books: http://shop.oreilly.com/product/9780596009571.do http://www.packtpub.com/mysql-51-plugin-development/book There's MySQL internals manual: http://dev.mysql.com/doc/internals/en/index.html There's MariaDB Knowledge Base that includes pages about MariaDB internals: http://kb.askmonty.org/ There're numerous blog posts and presentations about specific topics. Regards, Sergei

1 0

[Maria-developers] Getting started with the coding.
by sriram patil 23 May '14

23 May '14

Hi Alexander, I have started working on "CREATE OR REPLACE DATABASE" implementation. I thought this one has the least complexity among all the other commands. I am getting my hand-on debugging the source code too. I have made the required changes in sql_yacc.yy. The command is parsed properly. Handled the error where CREATE OR REPLACE and IF NOT EXISTS cannot occur at the same time. This is how I am thinking of proceeding with the implementation, In method mysql_create_db after checking the flag HA_LEX_CREATE_REPLACE. I am removing the database by calling mysql_rm_db and then the current implementation will take care of creating the new db with the same name. This seems correct? Or is there anything I need to consider? Thanks, Sriram

2 1

[Maria-developers] delete + offset
by Roberto Spadim 21 May '14

21 May '14

hi guys! i was thinking at maria-discuss, and i have a new "feature request" to mariadb DELETE statment, that's the OFFSET clausule, like sqlite my idea is... i have a table with history about for example temperature, and i will only record last 5000 records, my idea is execute a 'cleanup' for example every day instead of: select date_time from history where channel=1234 order by date_time desc limit 1 offset 5000 delete from history where channel=1234 and data_time<value from previous query i was considering something like delete from history where channel=1234 order by date_time desc limit 99999999999 offset 5000 what you think about this? -- Roberto Spadim SPAEmpresarial Eng. Automação e Controle

1 0

[Maria-developers] Regarding debugging MariaDB
by sriram patil 17 May '14

17 May '14

Hi Alexander, I wanted to run mysqld in debug mode to check the trace file and get to know workflow of SQL commands. I tried following command mysqld --user=<username> --debug Then, after connecting I executed some commands. But, the trace file is not created in /tmp folder. Is there anything I need to do while building the source code in order for the debug mode to work? Thanks, Sriram

2 1

[Maria-developers] Merging FusionIO changes to 10.0.12
by Colin Charles 16 May '14

16 May '14

Hi all, MariaDB has worked actively with Fusion-io, and we did release some improvements in a preview release a little over a month ago: https://blog.mariadb.org/significant-performance-boost-with-new-mariadb-pag… This was originally planned to be included into 10.0.10, but when we released the GA, we thought that the feature was not tested thoroughly. Now the code has proven stable we are thinking of merging this into 10.0.12. Yes, we know its already a GA, but this feature will be turned off by default, and the code is safely encapsulated. If you are not using Fusion-io or do not turn it on, there is no effect to you. To check, the changes are in the XtraDB and InnoDB that we ship (storage/xtradb & storage/innobase). Naturally, for those using Fusion-io devices, the benefits are clear - you will see significant improvements in speed and you will increase the lifetime of your cards. Think of this like adding drivers to the Linux kernel from time to time ;) What does everyone think? Package maintainers? Thanks! -- Colin Charles, Chief Evangelist, SkySQL - The MariaDB Company blog: http://bytebot.net/blog/| t: +6-012-204-3201 | Skype: colincharles

3 2

[Maria-developers] LIMIT ROWS MATCHED
by Colin Charles 16 May '14

16 May '14

Hi! http://seonguck.blogspot.kr/2014/05/limit-rows-matched.html We have a potential contribution here for a LIMIT ROWS MATCHED feature - might be interesting for us to consider this for 10.1 ? cheers, -colin -- Colin Charles, Chief Evangelist, SkySQL - The MariaDB Company blog: http://bytebot.net/blog/| t: +6-012-204-3201 | Skype: colincharles

2 1

[Maria-developers] tokudb database - generated "should never happen" status when mysql log partition ENOSP
by Daniel Black 15 May '14

15 May '14

1 0