MySQL Forums
Forum List  »  Performance

Re: drop and recreate index in mysql DB
Posted by: Ra Nala
Date: November 30, 2015 01:34AM

Rick James Wrote:
-------------------------------------------------------
> Short answer:
>
> CREATE table with all the indexes and don't worry
> about them.
>
> Long answer:
>
> * If you are loading one row at a time (that is a
> million INSERTs) into an existing table, have the
> indexes in place all the time.
>
> * If you are _initially_ loading a table, and
> nothing else is going on other than loading the
> table, it _may_ be faster to have the PRIMARY KEY
> and FOREIGN KEYs in place, but add the secondary
> keys later.
>
> * If you turn off / DROP an index, do some
> loading, then turn on / CREATE the index(es), that
> is bad if you are also accessing the table at the
> same time.
>
> * If practical, use LOAD DATA with a million-row
> file. This will perform the load in the
> fastest(?) possible way.
>
> Unrelated comments:
>
--------------------------------------------------------------
> * Why is there a `prd01` and `prd01_stg`? They
> have the same schema?
>

Ra nala :- Tables prd01` and `prd01_stg are in same/database. prd01_stg mean, it will be useful for incremental records, that is for cleansing and loading data purpose. and prd01 is my target datamart table which will maintain all history data.
----------------------------------------------------------
> * `prd01` -- does this mean that there is a
> `prd02`, `prd03`, etc? Yuck!
>
Ra nala :- exactly whatever you have guessed is correct, i have `prd02`, `prd03,prd04 these are for my multilingual data. and these are exactly useful in cogno framework manager to retrive multi language data based on locale logic.

----------------------------------------------------------------
> * Why are almost all the columns NULL? That seems
> unrealistic.
>
Ra nala :- No i am not having all columns having NULL data, my intention is if i
have null then is it better to replace all with NULL, as you mentioned in your thread.
--------------------------------------------------------------
> * I see 3 sets of code+type+name fields --
> "arrays" usually should be be implemented as
> multiple columns; instead have another table.
> Ditto for ca_1/2/3.

Ra nala :- yes we can maitainf code,type,name columns as per my business logic example:

i have NOKIA mobile then it is having itecm code, what type code of phone it is, what type of name it is.

I hope, terminology will typical to you,but that is per my business implementation

Options: ReplyQuote


Subject
Views
Written By
Posted
1640
November 25, 2015 05:48AM
975
November 26, 2015 02:31PM
1522
November 27, 2015 12:33AM
1720
November 29, 2015 11:38AM
Re: drop and recreate index in mysql DB
1212
November 30, 2015 01:34AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.