Re: [HACKERS] TOAST compression

2006-02-27 Thread Qingqing Zhou
Josh Berkus josh@agliodbs.com wrote While I'm waiting to figure out how to get the size of the toast table, at least I can provide the speed of query with/without assumed compression on the 6K text columns. Check out the table_size view in the newsysviews project. Andrew computed the

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Mark Woodward
Mark Woodward wrote: If you require a policy, then YOU are free to choose the policy that YOU need. You're not forced to accept other peoples' policies that may conflict with things in your environment. The problem is that there is no mechanism through which one can implement policy.

Re: [HACKERS] Scrollable cursors and Sort performance

2006-02-27 Thread Simon Riggs
On Sun, 2006-02-26 at 19:26 -0500, Tom Lane wrote: Simon Riggs [EMAIL PROTECTED] writes: On Fri, 2006-02-10 at 11:58 -0500, Tom Lane wrote: I suspect that the right thing is not to see this as a planner issue at all, but to try to drive the choice off the context in which the plan gets

Re: [HACKERS] Scrollable cursors and Sort performance

2006-02-27 Thread Tom Lane
Simon Riggs [EMAIL PROTECTED] writes: On Sun, 2006-02-26 at 19:26 -0500, Tom Lane wrote: After looking at my old notes about Materialize, I am thinking that we should add a int flags parameter to the InitNode calls along with ExecutorStart and probably PortalStart. Design-wise I was looking

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Martijn van Oosterhout
On Mon, Feb 27, 2006 at 09:39:59AM -0500, Mark Woodward wrote: It isn't just an environment variable, it is a number of variables and a mechanism. Besides, profile, from an admin's perspective, is for managing users, not databases. Sure, you need to control the user, group, placement of

Re: [HACKERS] User privileges-verification required

2006-02-27 Thread Nauman Naeem
Yeah it really was :-) BTW Ihave implemented this for multiuser-mode as well..Both the approaches as mentioned in my very first email... 1- The minimum super user count should not be less then 1. 2- Only the main database system owner is eligible to reassign. My personal believe is, this

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Mark Woodward
On Mon, Feb 27, 2006 at 09:39:59AM -0500, Mark Woodward wrote: It isn't just an environment variable, it is a number of variables and a mechanism. Besides, profile, from an admin's perspective, is for managing users, not databases. Sure, you need to control the user, group, placement of

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Dave Page
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mark Woodward Sent: 27 February 2006 16:49 To: Martijn van Oosterhout Cc: pgsql-hackers@postgresql.org Subject: Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf Think of Arthur

[HACKERS] Any conclusion on the Xeon context-switching issue?

2006-02-27 Thread Richard Huxton
Subject says it all really. I've got a new client who seems to be suffering from it, and I'm not sure if any conclusion was reached. -- Richard Huxton Archonet Ltd ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Tom Lane
Josh Berkus josh@agliodbs.com writes: No way. The entire point of information_schema is that it is standard; adding non-spec things to it renders it no better than direct access to the PG catalogs. Hmmm ... so, per you, we can't add extra views covering non-spec objects to the

Re: [HACKERS] Any conclusion on the Xeon context-switching issue?

2006-02-27 Thread Tom Lane
Richard Huxton dev@archonet.com writes: Subject says it all really. I've got a new client who seems to be suffering from it, and I'm not sure if any conclusion was reached. What's he using? 8.1 seems to have alleviated the problem somewhat, and I've done more work in CVS tip. It'll never go

Re: [HACKERS] Any conclusion on the Xeon context-switching issue?

2006-02-27 Thread Richard Huxton
Tom Lane wrote: Richard Huxton dev@archonet.com writes: Subject says it all really. I've got a new client who seems to be suffering from it, and I'm not sure if any conclusion was reached. What's he using? 8.1 seems to have alleviated the problem somewhat, and I've done more work in CVS tip.

Re: [HACKERS] Any conclusion on the Xeon context-switching issue?

2006-02-27 Thread Tom Lane
Richard Huxton dev@archonet.com writes: Tom Lane wrote: What's he using? 7.4.12 (.12 as of last week). I've seen context-switching peak at 8 on a quad-Xeon that really shouldn't be straining. Try 8.1.3. regards, tom lane ---(end of

Re: [HACKERS] Any conclusion on the Xeon context-switching issue?

2006-02-27 Thread Richard Huxton
Tom Lane wrote: Richard Huxton dev@archonet.com writes: Tom Lane wrote: What's he using? 7.4.12 (.12 as of last week). I've seen context-switching peak at 8 on a quad-Xeon that really shouldn't be straining. Try 8.1.3. Thanks. I'll see if we can run a parallel installation overnight

Re: [HACKERS] Scrollable cursors and Sort performance

2006-02-27 Thread Simon Riggs
On Mon, 2006-02-27 at 10:07 -0500, Tom Lane wrote: Simon Riggs [EMAIL PROTECTED] writes: On Sun, 2006-02-26 at 19:26 -0500, Tom Lane wrote: After looking at my old notes about Materialize, I am thinking that we should add a int flags parameter to the InitNode calls along with

[HACKERS] Dead Space Map

2006-02-27 Thread Heikki Linnakangas
Hi, The idea of using a so called dead space map to speed up vacuum has come up multiple times in this list in the last couple of years. I wrote an initial implementation of it to measure the performance impact it has on updates and on vacuum. Potential uses for a dead space map are: *

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Luke Lonergan
Heikki, On 2/27/06 9:53 AM, Heikki Linnakangas [EMAIL PROTECTED] wrote: My current implementation stores a bitmap of 32k bits in the special space of every 32k heap pages. Each bit in the bitmap corresponds one heap page. The bit is set every time a tuple is updated, and it's cleared by

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Tom Lane
Heikki Linnakangas [EMAIL PROTECTED] writes: Vacuum will need to be modified to use index lookups to find index tuples corresponding the dead heap tuples. Otherwise you have to scan through all the indexes anyway. This strikes me as a fairly bad idea, because it makes VACUUM dependent on

[HACKERS] Automatic free space map filling

2006-02-27 Thread Peter Eisentraut
Something came to my mind today, I'm not sure if it's feasible but I would like to know opinions on it. We've seen database applications that PostgreSQL simply could not manage because one would have to vacuum continuously. Perhaps in those situations one could arrange it that an update (or

Re: [HACKERS] [PATCHES] display and expression of the home directory in Win32

2006-02-27 Thread Hiroshi Saito
Hi All. I have thought this way and that since that time. Suggestion of Magnus-san was considered and this was made. I considered many things about the pgpass guide of libpq. In windows, even the place of it was not clear. Furthermore, they are intricately concerned with an environment

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Clark C. Evans
On Mon, Feb 27, 2006 at 11:39:30AM -0500, Tom Lane wrote: | Josh Berkus josh@agliodbs.com writes: | No way. The entire point of information_schema is that it is standard; | adding non-spec things to it renders it no better than direct access | to the PG catalogs. | | Hmmm ... so, per you, we

Re: [HACKERS] Automatic free space map filling

2006-02-27 Thread Tom Lane
Peter Eisentraut [EMAIL PROTECTED] writes: We've seen database applications that PostgreSQL simply could not manage because one would have to vacuum continuously. Perhaps in those situations one could arrange it that an update (or delete) of a row registers the space in the free space map

Re: [HACKERS] [PATCHES] display and expression of the home directory in Win32

2006-02-27 Thread Tom Lane
Hiroshi Saito [EMAIL PROTECTED] writes: C:\Program Files\PostgreSQL\8.1\binpqpasswd.exe --help pqpasswd installs a pgpass(libpq) connect a PostgreSQL database. I must be missing something. What exactly does this accomplish that couldn't be done at least as flexibly with a simple text editor?

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Andrew - Supernews
On 2006-02-27, Tom Lane [EMAIL PROTECTED] wrote: I do have doubts about adding any large number of add-on views to pg_catalog, because of the privileged place of that schema in search paths. It'd be better to put them in a separate schema (pg_info maybe?) where they'd pose less risk of

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Josh Berkus
Tom, Hmmm ... so, per you, we can't add extra views covering non-spec objects to the information_schema (like aggregates) because we can't modify it in any way. But per Peter we can't add new views to the pg_catalog because we want people to use information_schema. I sense a catch-22 here.

Re: [HACKERS] [PATCHES] display and expression of the home directory in Win32

2006-02-27 Thread Hiroshi Saito
Thank you for a quick response. From: Tom Lane C:\Program Files\PostgreSQL\8.1\binpqpasswd.exe --help pqpasswd installs a pgpass(libpq) connect a PostgreSQL database. I must be missing something. What exactly does this accomplish that couldn't be done at least as flexibly with a simple

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Tom Lane
Josh Berkus josh@agliodbs.com writes: Yes, I agree with him on that. However, there's a certain amount of confusion inspired by the organization that: If you want to look up the table's columns go to information_schmea, if you want the table *size* go to sysviews. But maybe that's

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Andrew Dunstan
Andrew - Supernews wrote: On 2006-02-27, Tom Lane [EMAIL PROTECTED] wrote: I do have doubts about adding any large number of add-on views to pg_catalog, because of the privileged place of that schema in search paths. It'd be better to put them in a separate schema (pg_info maybe?) where

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Josh Berkus
Andrew, How fine-grained do we want to get on namespaces? I'd be slightly more inclined to have pg_info or maybe pg_utils as a place to stash not only extra system views but other utility stuff that we want to ship but is essentially droppable. AFAIK, none of the contributors to newsysviews

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Martijn van Oosterhout
On Mon, Feb 27, 2006 at 11:48:50AM -0500, Mark Woodward wrote: Well, I'm sure that one could use debian's solution, but that's the problem, it isn't PostgreSQL's solution. Shouldn't PostgreSQL provide the mechanisms? Will debian support FreeBSD? NetBSD? Is it in the PostgreSQL admin manual? I

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Josh Berkus
Mark, Well, I'm sure that one could use debian's solution, but that's the problem, it isn't PostgreSQL's solution. Shouldn't PostgreSQL provide the mechanisms? Will debian support FreeBSD? NetBSD? Is it in the PostgreSQL admin manual? We are talking about a feature, like pg_service.conf,

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Mark Woodward
On Mon, Feb 27, 2006 at 11:48:50AM -0500, Mark Woodward wrote: Well, I'm sure that one could use debian's solution, but that's the problem, it isn't PostgreSQL's solution. Shouldn't PostgreSQL provide the mechanisms? Will debian support FreeBSD? NetBSD? Is it in the PostgreSQL admin manual?

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Heikki Linnakangas
On Mon, 27 Feb 2006, Tom Lane wrote: Heikki Linnakangas [EMAIL PROTECTED] writes: Vacuum will need to be modified to use index lookups to find index tuples corresponding the dead heap tuples. Otherwise you have to scan through all the indexes anyway. This strikes me as a fairly bad idea,

Re: [HACKERS] Any conclusion on the Xeon context-switching issue?

2006-02-27 Thread Jeffrey W. Baker
On Mon, 2006-02-27 at 16:54 +, Richard Huxton wrote: Tom Lane wrote: Richard Huxton dev@archonet.com writes: Subject says it all really. I've got a new client who seems to be suffering from it, and I'm not sure if any conclusion was reached. What's he using? 8.1 seems to have

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Tom Lane
Heikki Linnakangas [EMAIL PROTECTED] writes: On Mon, 27 Feb 2006, Tom Lane wrote: This strikes me as a fairly bad idea, because it makes VACUUM dependent on correct functioning of user-written code --- consider a functional index involving a user-written function that was claimed to be

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Mark Woodward
Mark, Well, I'm sure that one could use debian's solution, but that's the problem, it isn't PostgreSQL's solution. Shouldn't PostgreSQL provide the mechanisms? Will debian support FreeBSD? NetBSD? Is it in the PostgreSQL admin manual? We are talking about a feature, like pg_service.conf,

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Joshua D. Drake
Maybe I'm too used to working in engineering groups. I am trying to get input for a project. Trying to iron out what the feature set should be and the objectives that should be attained. BEFORE I start coding. Well that is always a good idea but: Just saying submit a patch is the

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Jim C. Nasby
On Mon, Feb 27, 2006 at 11:24:05AM -0800, Josh Berkus wrote: Andrew, How fine-grained do we want to get on namespaces? I'd be slightly more inclined to have pg_info or maybe pg_utils as a place to stash not only extra system views but other utility stuff that we want to ship but is

Re: [HACKERS] constraints and sql92 information_schema compliance

2006-02-27 Thread Jim C. Nasby
On Mon, Feb 27, 2006 at 02:17:03PM -0500, Tom Lane wrote: Josh Berkus josh@agliodbs.com writes: Yes, I agree with him on that. However, there's a certain amount of confusion inspired by the organization that: If you want to look up the table's columns go to information_schmea, if you

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Tom Lane
Mark Woodward [EMAIL PROTECTED] writes: My frustration level often kills any desire to contribute to open source. Sometimes, I think that open source is doomed. The various projects I track and use are very frustrating, they remind me of dysfunctional engineering departments in huge companies,

[HACKERS] Scanning for insert

2006-02-27 Thread James William Pye
Greets, [Ugh, sent one with uncompressed patch. Seems to be swallowed(No failure msg?). Ignore it if it surfaces.] The attached patch extends pg_am by adding two methods, scan for insert and insert from scan. These methods are meant to provide an index user with the ability to do conditional

Re: [HACKERS] Scanning for insert

2006-02-27 Thread Tom Lane
James William Pye [EMAIL PROTECTED] writes: The attached patch extends pg_am by adding two methods, scan for insert and insert from scan. These methods are meant to provide an index user with the ability to do conditional insertions based on the results of a conclusive locking scan--a scan

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Martijn van Oosterhout
On Mon, Feb 27, 2006 at 03:38:23PM -0500, Mark Woodward wrote: Maybe I'm too used to working in engineering groups. I am trying to get input for a project. Trying to iron out what the feature set should be and the objectives that should be attained. BEFORE I start coding. Well yes, the problem

Re: [HACKERS] Scrollable cursors and Sort performance

2006-02-27 Thread Jim C. Nasby
On Mon, Feb 27, 2006 at 02:17:23PM +, Simon Riggs wrote: Interesting point: how should EXPLAIN ANALYZE set these bits? For its own purposes it need not request random access, but it might be interesting to make it possible to examine both the random and nonrandom behaviors, now that

Re: [HACKERS] Scrollable cursors and Sort performance

2006-02-27 Thread Tom Lane
Jim C. Nasby [EMAIL PROTECTED] writes: On Mon, Feb 27, 2006 at 02:17:23PM +, Simon Riggs wrote: Possibly we could make EXPLAIN ANALYZE EXECUTE set the random-access bits. Good point. Whichever we do will be wrong in some cases I've no real opinion on this other than a vague

Re: [HACKERS] Scrollable cursors and Sort performance

2006-02-27 Thread Jim C. Nasby
On Mon, Feb 27, 2006 at 06:01:21PM -0500, Tom Lane wrote: Jim C. Nasby [EMAIL PROTECTED] writes: On Mon, Feb 27, 2006 at 02:17:23PM +, Simon Riggs wrote: Possibly we could make EXPLAIN ANALYZE EXECUTE set the random-access bits. Good point. Whichever we do will be wrong in some

Re: [HACKERS] Scrollable cursors and Sort performance

2006-02-27 Thread Tom Lane
Jim C. Nasby [EMAIL PROTECTED] writes: On Mon, Feb 27, 2006 at 06:01:21PM -0500, Tom Lane wrote: There is no EXPLAIN ANALYZE DECLARE, and AFAICS it would be a contradiction in terms to have one, since DECLARE doesn't run the query. You have no idea how glad I am that I'm not the only one who

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Jim C. Nasby
On Mon, Feb 27, 2006 at 01:17:36PM -0500, Tom Lane wrote: * vacuuming pages one by one as they're written by bgwriter That's not happening. VACUUM has to be a transaction and the bgwriter does not run transactions; nor is it in any position to clean out index entries associated with a heap

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Jim C. Nasby
On Mon, Feb 27, 2006 at 03:05:41PM -0500, Tom Lane wrote: Heikki Linnakangas [EMAIL PROTECTED] writes: On Mon, 27 Feb 2006, Tom Lane wrote: This strikes me as a fairly bad idea, because it makes VACUUM dependent on correct functioning of user-written code --- consider a functional index

[HACKERS] In case nobody has seen this survey from Sun ...

2006-02-27 Thread Marc G. Fournier
Just got posted to the FreeBSD list ... has several questions that revolve around the BSD vs GPL licensing, and somewhere that 'omit' PostgreSQL as an OS option (while others include it) ... http://enews.sun.com/CTServlet?id=103018442-968290480:1141071714252 Marc G. Fournier

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Josh Berkus
Mark, My frustration level often kills any desire to contribute to open source. Sometimes, I think that open source is doomed. The various projects I track and use are very frustrating, they remind me of dysfunctional engineering departments in huge companies, it is very hard to positively

Re: [HACKERS] possible design bug with PQescapeString()

2006-02-27 Thread Tatsuo Ishii
FYI I have sent an email to cores to ask if I am OK to bring another but closely related to this issue to open discussions, whose details have already been sent to them. The reason why I'm asking is, if this issue could be open, then the issue might be open too and that makes discussions easier.

Re: [HACKERS] Scanning for insert

2006-02-27 Thread James William Pye
On Mon, Feb 27, 2006 at 05:44:20PM -0500, Tom Lane wrote: Is this really a good idea? The fundamental problem I see with it is that it takes away the index AM's ability to make any guarantees about its locking behavior, ie, how long locks will be held or what other operations might intervene

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Bruce Momjian
Mark Woodward wrote: Mark, Well, I'm sure that one could use debian's solution, but that's the problem, it isn't PostgreSQL's solution. Shouldn't PostgreSQL provide the mechanisms? Will debian support FreeBSD? NetBSD? Is it in the PostgreSQL admin manual? We are talking about a

[HACKERS] Vacuum dead tuples that are between transactions

2006-02-27 Thread Paul Tillotson
The topic of improving vacuum for use in heavy-update environments seems to come up frequently on the list. Has anyone weighed the costs of allowing VACUUM to reclaim tuples that are not older than the oldest transaction but are nonetheless invisible to all running transactions? It seems

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Mark Woodward
Mark Woodward [EMAIL PROTECTED] writes: My frustration level often kills any desire to contribute to open source. Sometimes, I think that open source is doomed. The various projects I track and use are very frustrating, they remind me of dysfunctional engineering departments in huge

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Mark Woodward
Mark Woodward wrote: Mark, Well, I'm sure that one could use debian's solution, but that's the problem, it isn't PostgreSQL's solution. Shouldn't PostgreSQL provide the mechanisms? Will debian support FreeBSD? NetBSD? Is it in the PostgreSQL admin manual? We are talking about a

Re: [HACKERS] pg_config, pg_service.conf, postgresql.conf ....

2006-02-27 Thread Bruce Momjian
I don't see how this is much better than just pointing to different configuration file for each postmaster. --- Mark Woodward wrote: One question I have is how this feature would be an improvement over just pointing

[HACKERS] character encoding in StartupMessage

2006-02-27 Thread John DeSoi
I could not find anything in the Frontend/Backend protocol docs about character encoding in the StartupMessage. Assuming it is legal for a database or user name to have unicode characters, how is this handled when nothing yet has been said about the client encoding? Thanks, John DeSoi,

Re: [HACKERS] character encoding in StartupMessage

2006-02-27 Thread Christopher Kings-Lynne
I could not find anything in the Frontend/Backend protocol docs about character encoding in the StartupMessage. Assuming it is legal for a database or user name to have unicode characters, how is this handled when nothing yet has been said about the client encoding? A similar badness is that

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Tom Lane
Jim C. Nasby [EMAIL PROTECTED] writes: On Mon, Feb 27, 2006 at 03:05:41PM -0500, Tom Lane wrote: Moreover, you haven't pointed to any strong reason to adopt this methodology. It'd only be a win when vacuuming pretty small numbers of tuples, which is not the design center for VACUUM, and isn't

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Greg Stark
Tom Lane [EMAIL PROTECTED] writes: Heikki Linnakangas [EMAIL PROTECTED] writes: * implementation of index-only scans An index scan would not have to check the visibility information of heap tuples on those heap pages that are marked as clean in the dead space map. This requires that

Re: [HACKERS] Vacuum dead tuples that are between transactions

2006-02-27 Thread Tom Lane
Paul Tillotson [EMAIL PROTECTED] writes: The topic of improving vacuum for use in heavy-update environments seems to come up frequently on the list. Has anyone weighed the costs of allowing VACUUM to reclaim tuples that are not older than the oldest transaction but are nonetheless

Re: [HACKERS] character encoding in StartupMessage

2006-02-27 Thread Tom Lane
Christopher Kings-Lynne [EMAIL PROTECTED] writes: I could not find anything in the Frontend/Backend protocol docs about character encoding in the StartupMessage. Assuming it is legal for a database or user name to have unicode characters, how is this handled when nothing yet has been said

[HACKERS] ipcclean in 8.1 broken?

2006-02-27 Thread Christopher Kings-Lynne
I just tried using ipcclean in 8.1.3. It doesn't work when I su to the pgsql user. This part of the script: if [ $USER = 'root' -o $LOGNAME = 'root' ] Always fails because even tho $USER is set to 'pgsql' when su'ed, $LOGNAME is still root. This is on FreeBSD 4.9 Chris

Re: [HACKERS] character encoding in StartupMessage

2006-02-27 Thread Christopher Kings-Lynne
I don't see any very nice solution at the moment. Once we get support for per-column locales, it might be possible to declare that the shared catalogs are always in UTF8 encoding and get the necessary conversions to happen automatically. At the very least, could we always convert dbnames and

Re: [HACKERS] Dead Space Map

2006-02-27 Thread Hannu Krosing
Ühel kenal päeval, E, 2006-02-27 kell 13:17, kirjutas Tom Lane: Heikki Linnakangas [EMAIL PROTECTED] writes: Vacuum will need to be modified to use index lookups to find index tuples corresponding the dead heap tuples. Otherwise you have to scan through all the indexes anyway. This