Re: Information about Access methods

Hi,

I am looking in Postgresql code for the first time. Specifically in
Indexing scheme.

I want to focus on B tree for my testing.

Inside access methods in Backend, I found "Index" folder and "Btree" folder
but i don't know which code to look for. i want to change something in B
tree implementation.

Please guide.

Regards,
Rohit Goyal

On 11/12/2013 07:00 PM, Rohit Goyal wrote:
>
> Inside access methods in Backend, I found "Index" folder and "Btree"
> folder but i don't know which code to look for. i want to change
> something in B tree implementation.
>

Start here:

http://www.postgresql.org/docs/current/static/indexam.html

--
Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services

Hi,
Thanks for document. It was really helpful.
Now, as index folder contains basically interface for all index type, do I
need to change it, if I want to modify only b tree index algorithm?

Do I need to change only btree index files or Do i have to change index
folder files like indexam.c
Please confirm. :)

Regards,
Rohit

On Tue, Nov 12, 2013 at 1:22 PM, Craig Ringer <craig(at)2ndquadrant(dot)com> wrote:

> On 11/12/2013 07:00 PM, Rohit Goyal wrote:
> >
> > Inside access methods in Backend, I found "Index" folder and "Btree"
> > folder but i don't know which code to look for. i want to change
> > something in B tree implementation.
> >
>
> Start here:
>
> http://www.postgresql.org/docs/current/static/indexam.html
>
> --
> Craig Ringer http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Training & Services
>

--
Regards,
Rohit Goyal

On 11/13/2013 06:36 AM, Rohit Goyal wrote:
> Hi,
> Thanks for document. It was really helpful.
> Now, as index folder contains basically interface for all index type, do
> I need to change it, if I want to modify only b tree index algorithm?
>
> Do I need to change only btree index files or Do i have to change index
> folder files like indexam.c

Without knowing what you are trying to do, it's really hard to answer
that usefully. In general if you want to modify b-tree indexes you'd
only have to modify the b-tree index implementation. If you want to add
new capabilities or features to the indexing system in general then use
them in b-tree, you'd probably also have to modify the access method
interface.

If you aren't just doing this for learning/research you should explain
in detail what you are trying to do. There is no point spending lots of
time creating a patch that would never get accepted into the PostgreSQL
core, so you have to maintain it forever more...

--
Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services

On Wed, Nov 13, 2013 at 2:42 AM, Craig Ringer <craig(at)2ndquadrant(dot)com> wrote:

> On 11/13/2013 06:36 AM, Rohit Goyal wrote:
> > Hi,
> > Thanks for document. It was really helpful.
> > Now, as index folder contains basically interface for all index type, do
> > I need to change it, if I want to modify only b tree index algorithm?
> >
> > Do I need to change only btree index files or Do i have to change index
> > folder files like indexam.c
>
> Without knowing what you are trying to do, it's really hard to answer
> that usefully. In general if you want to modify b-tree indexes you'd
> only have to modify the b-tree index implementation. If you want to add
> new capabilities or features to the indexing system in general then use
> them in b-tree, you'd probably also have to modify the access method
> interface.
>
> If you aren't just doing this for learning/research you should explain
> in detail what you are trying to do. There is no point spending lots of
> time creating a patch that would never get accepted into the PostgreSQL
> core, so you have to maintain it forever more...
>

> --
> Craig Ringer http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Training & Services
>
Hi,

Thanks for update. Actually, I am doing it for learning. I want to modify B
tree approach for insert and update operation to perform in a more faster
way.
Could you please suggest something about abt update operation of B tree
index.

Regards,
Rohit Goyal

On 11/13/2013 08:59 AM, Rohit Goyal wrote:
> Could you please suggest something about abt update operation of B tree
> index.

access/nbtree/README is probably the next text to read. It points to
theoretical background and also explains specifics of Postgres
implementation.

// Antonin Houska (Tony)