dhis2-devs team mailing list archive

[Saptarshi Purkayastha <sunbiz@xxxxxxxxx>]

Thanks... can we not write code at the application startup that if that
crosstab table is found it should be dropped??
---
Regards,
Saptarshi PURKAYASTHA
Director R & D, HISP India
Health Information Systems Programme

My Tech Blog:  http://sunnytalkstech.blogspot.com
You Live by CHOICE, Not by CHANCE


2009/3/28 Lars Helge Øverland <larshelge@xxxxxxxxx>

>
>
> On Sat, Mar 28, 2009 at 2:46 PM, Saptarshi Purkayastha <sunbiz@xxxxxxxxx>wrote:
>
>> While trying to look at the data model of dhis2, I was surprised to see
>> that a table called "datavaluecrosstab" is holding 185 columns (basically
>> the number of data elements).
>>
>> A cross tabulated query must have created this pivoted, denormalized
>> output, but why is it still existing in the database?? Basically the cross
>> tabulated table should have been a temporary table generated by a query on
>> data mart processing and should have been dropped when the query processing
>> is done. Either that, or we should use multiple threads to process different
>> parts of the data marts tree...
>>
>> Is this a bug?? Or do we have some explanation why this table is still in
>> the database?? Or is it a point where we can optimize code??
>>
>
> The datamart removes the datavaluecrosstab after the export process
> finishes. This must be caused by an aborted or failed export process, you
> can just delete it.
>
>
>
>> Another observation is that we have a few tables that are using MyISAM
>> Engine and most others are InnoDB Engine. I don't see why we are using
>> MyISAM for only a few tables. If we are thinking that MyISAM will increase
>> performance, then we are following a myth that has been dismissed many times
>> when using latest versions of MySQL.
>>
>
> This must be caused by someone in India modifying the database engine of
> these tables. Innodb is default and all my databases from SL, SA etc use
> only innodb tables.
>
>
> Lars
>
>
>