[PATCH] indexability of << operator for inet/cidr

Started by Alex Pilosovalmost 25 years ago5 messageshackers
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#1Alex Pilosov
alex@pilosoft.com

Attached is a patch that explains to optimizer that its possible to use
index when performing a << b where a is an inet/cidr value and b is a
constant.

Indexpath generated for such an expression is this:
(a > network(b)) and (a <= set_masklen(broadcast(b, 32)))

Since this is my first time delving in the guts of postgres, someone
definitely should review it :)

I mostly based my code on prefix_quals function for string types.

Thanks

Attachments:

pg-index-inetsub.patchtext/plain; charset=US-ASCII; name=pg-index-inetsub.patchDownload+154-0
#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Alex Pilosov (#1)
Re: [PATCH] indexability of << operator for inet/cidr

Alex Pilosov <alex@pilosoft.com> writes:

Indexpath generated for such an expression is this:
(a > network(b)) and (a <= set_masklen(broadcast(b, 32)))

What happens to that set_masklen thing for IPv6?

If the network.c code were exporting a function that made this value,
I'd not worry; but I don't like wiring an IPv4 assumption into code far
away in the planner. Can't we do better here? Perhaps move the
generation of the indexscan bound values into a subroutine in network.c?

regards, tom lane

#3Bruce Momjian
bruce@momjian.us
In reply to: Alex Pilosov (#1)
Re: [PATCH] indexability of << operator for inet/cidr

Your patch has been added to the PostgreSQL unapplied patches list at:

http://candle.pha.pa.us/cgi-bin/pgpatches

I will try to apply it within the next 48 hours.

Attached is a patch that explains to optimizer that its possible to use
index when performing a << b where a is an inet/cidr value and b is a
constant.

Indexpath generated for such an expression is this:
(a > network(b)) and (a <= set_masklen(broadcast(b, 32)))

Since this is my first time delving in the guts of postgres, someone
definitely should review it :)

I mostly based my code on prefix_quals function for string types.

Thanks

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#4Alex Pilosov
alex@pilosoft.com
In reply to: Tom Lane (#2)
Re: [PATCH] indexability of << operator for inet/cidr

On Thu, 14 Jun 2001, Tom Lane wrote:

Alex Pilosov <alex@pilosoft.com> writes:

Indexpath generated for such an expression is this:
(a > network(b)) and (a <= set_masklen(broadcast(b, 32)))

What happens to that set_masklen thing for IPv6?

If the network.c code were exporting a function that made this value,
I'd not worry; but I don't like wiring an IPv4 assumption into code far
away in the planner. Can't we do better here? Perhaps move the
generation of the indexscan bound values into a subroutine in network.c?

Good point. I already rewrote it, but I am going to send it in tomorrow, I
want to resync to HEAD, since some of network.c was taken in and I want to
have a clean patch for you guys :)

Thanks
-alex

#5Bruce Momjian
bruce@momjian.us
In reply to: Alex Pilosov (#1)
Re: [PATCH] indexability of << operator for inet/cidr

Patch removed from queue, awaiting updated version.

Attached is a patch that explains to optimizer that its possible to use
index when performing a << b where a is an inet/cidr value and b is a
constant.

Indexpath generated for such an expression is this:
(a > network(b)) and (a <= set_masklen(broadcast(b, 32)))

Since this is my first time delving in the guts of postgres, someone
definitely should review it :)

I mostly based my code on prefix_quals function for string types.

Thanks

Content-Description:

[ Attachment, skipping... ]

---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?

http://www.postgresql.org/users-lounge/docs/faq.html

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026