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

[高健 <luckyjackgao@xxxxxxxxx>]

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.klaver@xxxxxxxxx>

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

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.klaver@xxxxxxxxx