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Re: [GSOC 2014] CREATE OR REPLACE, CREATE IF NOT EXISTS, and DROP IF EXISTS
Hope this mail finds you well.
I have asked few things as comment on my proposal that I had submitted at
Can you please help me or guide me with the same ?
Thanks and Regards,
On Tue, Mar 18, 2014 at 10:51 PM, Sergei Golubchik <serg@xxxxxxxxxxx> wrote:
> Hi, Kesha!
> On Mar 18, Kesha Shah wrote:
> > Dear Sergei Golubchik,
> > Hope this mail finds you well.
> > I am Kesha Shah, a third year undergraduate from DA-IICT, Gandhinagar,
> > India. I was a Google Summer of Code student previous year as well as
> > Google Code-In mentor with BRL-CAD open source solid modeling
> > software. The activities related to my contributions at BRL-CAD at
> > logged by me at -
> > http://brlcad.org/wiki/User:KeshaSShah/GSoC13/Reports. My other
> > projects can be found at -
> > https://github.com/keshashah?tab=repositories.
> > I have good programming hands on C and C++ and would like to take up
> > and contribute at the Mariadb task of 'CREATE OR REPLACE, CREATE IF
> > NOT EXISTS, and DROP IF EXISTS' [MDEV-5359] as part of GSOC 2014. I
> > have studied database systems and compiler construction during my
> > academics. Your project would help to apply my knowledge by working at
> > deeper level of coding database internals, thereby contributing to
> > open source software.
> > I had checked out the mariadb master branch from bazaar and started
> > looking into the source code. I found the task more related to update
> > of the existing mariadb SQL parser. The parser seems to be implemented
> > as ascendant parser using bison parser generator (GNU version of
> > YACC). From the current findings I could see the YACC grammar file
> > sql_yacc.yy under maria/sql/ where I can see the rules defined for
> > CREATE PROCEDURE_SYM, CREATE FUNCTION_SYM, CREATE TRIGGER_SYM etc.
> > Alternatively I can see the *_SYM lexical tokens defined under the
> > /maria/sql/lex.h file. Similarly for DROP TABLESPACE_SYM, DROP
> > TRIGGER_SYM etc could be found. So when sql text input stream is
> > encountered from SQL interface, it is read and categorized into
> > lexical tokens by the lexer /maria/sql/sql_lex.cc in the lexical
> > analysis step. I tried to figure out that we will have to define
> > additional token 'IF' in the lex.h and 'NOT' and 'EXISTS' are already
> > defined.
> All three are already defined, look for CREATE TABLE IF NOT EXISTS, for
> > I am also looking at the existing user defined actions that
> > builds the AST nodes (sp_head being the root node for most types) when
> > relevant grammar rule is satisfied in case of DDL statements. After
> > semantic analysis (create of stored procs/functions), the next step
> > would be to amend/define actions for the newly introduced grammar of
> > handling check of existence of db artefact at the time of DDL
> > execution. Also at this step the compiler will have to query the
> > relevant storage engine on DB level or repository level to check if
> > the DB object exists. This would require me to spend more time on
> > understanding design pattern followed for the implementation of
> > classes and behaviours of each of the underlying db artefacts.
> > It would be interesting for me to know if the steps proposed by me
> > above are in the right direction or not ? Also I am aware that I am
> Yes, they look correct.
> > late in discussing my proposal with you. But I can assure that I will
> > be able to deliver the requirements in timely manner under your
> > guidance. I have formulated initial draft of my proposal and would
> > like to submit it at the earliest.