Re: pageinspect patch, for showing tuple data

On Fri, Sep 25, 2015 at 8:30 PM, Nikolay Shaplov wrote:
> Here is final version with documentation.

Thanks! I just had a short look at it:
- I am not convinced that it is worth declaring 3 versions of tuple_data_split.
- The patch does not respect the project code style, particularly
one-line "if condition {foo;}" are not adapted, code line is limited
to 80 characters, etc. The list is basically here:
http://www.postgresql.org/docs/current/static/source.html
- Be aware of typos: s/whitch/which is one.

+ <entry><structfield>t_infomask2</structfield></entry>
+ <entry><type>integer</type></entry>
+ <entry>stores number of attributes (11 bits of the word). The
rest are used for flag bits:
+<screen>
+0x2000 - tuple was updated and key cols modified, or tuple deleted
+0x4000 - tuple was HOT-updated
+0x8000 - this is heap-only tuple
+0xE000 - visibility-related bits (so called "hint bits")
+</screen>
This large chunk of documentation is a duplicate of storage.sgml. If
that's really necessary, it looks adapted to me to have more detailed
comments at code level directly in heapfuncs.c.

The example of tuple_data_split in the docs would be more interesting
if embedded with a call to heap_page_items.

> Hope it will be the last one. :-)

Unfortunately not :) But this is definitely going in the right
direction thinking that this code is mainly targeted for educational
purposes.
--
Michael