Re: How to know detailed information about HOT(Heap-Only Tuples)?

Hi:

Thank you all for kindly replying.

I think that I need this: pg_stat_user_tables.n_tup_hot_upd

And Adrian's information is a pretty good material for me to understand
the internal.

Best regards

2013/8/22 Adrian Klaver <adrian(dot)klaver(at)gmail(dot)com>

> On 08/21/2013 07:20 PM, 高健 wrote:
>
>> Hi:
>>
>> I have heard that Heap-Only Tuples is introduce from 8.3.
>> And I am searching information for it.
>>
>> How can I get a detailed information of HOT?
>>
>
> http://git.postgresql.org/**gitweb/?p=postgresql.git;a=**
> blob;f=src/backend/access/**heap/README.HOT;hb=HEAD<http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/access/heap/README.HOT;hb=HEAD>
>
>
> For example:
>> according to a table, How many tuples are heap only tuples , and how
>> many are not?
>>
>> And also , Is there any options which can influence HOT occurrance?
>>
>> Best Regards
>>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)gmail(dot)com
>