maria-developers team mailing list archive

[Sachin Setia <sachinsetia1001@xxxxxxxxx>]

Hello Sergei
Actually I was prototyping for blob and varchar   for aria and myisam
storage engine.
My prototype worked for complex definations like
craete table(abc int primary key, blob_col blob unique, varchar_col
varchar(1000) unique) engine=myisam;
Solved the issue of frm file incosistance.

As you suggested for doing it for innodb i am current working on it.Innodb
does not natively support hash based index.
when we run select distinct column from tbl;
it use create_internal_tmp_table() which uses maria storage engine for
creating tmp table.
But query like this works
MariaDB [sachin]> create table iu2(abc blob unique);
Query OK, 0 rows affected (0.04 sec)

MariaDB [sachin]> insert into iu2 values(1);
Query OK, 1 row affected (0.03 sec)

MariaDB [sachin]> insert into iu2 values(1);
ERROR 1062 (23000): Duplicate entry '1' for key 'abc'
this query does not use hash but it simply compares values
Will write a proposal shortly.

On Tue, Mar 22, 2016 at 4:20 PM, Sachin Setia <sachinsetia1001@xxxxxxxxx>
wrote:

> Hello Sergi
> Actually I was prototyping for blob and varchar   for aria and myisam
> storage engine.
> My prototype worked for complex definations like
> craete table(abc int primary key, blob_col blob unique, varchar_col
> varchar(1000) unique) engine=myisam;
> Solved the issue of frm file incosistance.
>
> As you suggested for doing it for innodb i am current working on it.Innodb
> does not natively support hash based index.
> when we run select distinct column from tbl;
> it use create_internal_tmp_table() which uses maria storage engine for
> creating tmp table.
> But query like this works
> MariaDB [sachin]> create table iu2(abc blob unique);
> Query OK, 0 rows affected (0.04 sec)
>
> MariaDB [sachin]> insert into iu2 values(1);
> Query OK, 1 row affected (0.03 sec)
>
> MariaDB [sachin]> insert into iu2 values(1);
> ERROR 1062 (23000): Duplicate entry '1' for key 'abc'
> this query does not use hash but it simply compares values
> Will write a proposal shortly.
>
>
> Regards
> sachin
>
> On Sat, Mar 19, 2016 at 1:52 AM, Sergei Golubchik <serg@xxxxxxxxxxx>
> wrote:
>
>> Hi, Sachin!
>>
>> On Mar 18, Sachin Setia wrote:
>> >
>> > ERROR 1030 (HY000): Got error 190 "Incompatible key or row definition
>> > between the MariaDB .frm file and the information in the storage engine.
>> > You have to dump an" from storage engine MyISAM
>> >
>> > We are getting this becuase in mi_create for each unique_def it creates
>> one
>> > keydef and writes it.And this creates two  problem
>> > 1. frm keydef algorithm is different from saved kefdef algorithm(always
>> > zero) for the time I have solved this problem .
>> >
>> > 2.Mismatch between keydef's keysegs the reason for this is when
>> mi_create
>> > creates keyseg for unique_def it did not keeps the orignal uniquedef's
>> > keyseg parameters in mind like language start length which creates
>> problem
>> > in check_definition function in ha_myisam.cc.I am currently working on
>> it
>> > Once again sorry for this foolish mistake.
>> > Regars
>> > sachin
>>
>> No problem, everyone makes mistakes :)
>>
>> It's a prototype, after all. It's much more important that you
>> understand how the code works and why it doesn't work.
>>
>> Regards,
>> Sergei
>> Chief Architect MariaDB
>> and security@xxxxxxxxxxx
>>
>
>