Re: [HACKERS] Separate shared_buffer management process

p-pip Sailesh http://www.cs.berkeley.edu/~sailesh Ph: (510) 642-8072 - Original Message - From: Bruce Momjian <[EMAIL PROTECTED]> Date: Wednesday, October 8, 2003 12:33 pm Subject: Re: [HACKERS] Separate shared_buffer management process > > Added to TODO: > > * Us

Re: [HACKERS] Concurrent connections in psql

+++ We'd love this feature as it would really help us write better test cases ! Regards Sailesh -- Sailesh Krishnamurthy Amalgamated Insight [W] (650) 242-3503 [C] (650) 804-6585 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gregory Stark

Re: [HACKERS] Concurrent connections in psql

+++ We'd love this feature as it would really help us write better test cases ! Regards Sailesh -- Sailesh Krishnamurthy Amalgamated Insight [W] (650) 242-3503 [C] (650) 804-6585 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gregory Stark

Re: [HACKERS] BITMAP Index support (and other DSS info.)

, it's not really close to a release yet ... :-) -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])

Re: [HACKERS] Implementing a new Join Algorithm

ecause we're actually implementing the Eddy operator. But if your goal is just to try out your nice new join algorithm, this would probably work and be a quick fix to get you started. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

[HACKERS] Question about bit.h and bit.c

I have a small nit Why is it that bit.h is in src/include/utils and bit.c is in src/backend/lib ? I can never for the life of me remember which is in which :-) -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP

Re: [HACKERS] Question about bit.h and bit.c

>>>>> "Tom" == Tom Lane <[EMAIL PROTECTED]> writes: Tom> Sailesh Krishnamurthy <[EMAIL PROTECTED]> writes: >> Why is it that bit.h is in src/include/utils and bit.c is in >> src/backend/lib ? Tom> Possibly a more interestin

Re: [HACKERS] Threads

T though, postgres code, such as perhaps the memory contexts is not MT-safe (of course the bufferpool/shmem accesses are safe). -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org

[HACKERS] docbook and postgresql

the newbie question, but if somebody could point me to what exactly I need to install, given that configure thinks that I do have docbook-3.1, I'd be obliged. Thanks ! -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

[HACKERS] set_ps_display on solaris x86

. Is there some magic incantation to be chanted to get this to work ? Thanks ! -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send

[HACKERS] PG_TEMP_FILES_DIR

Quick question for the group I'm assuming that the PG_TEMP_FILES_DIR for BufFile temps is automatically under the PGDATA directory. Is that correct ? -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)---

Re: [HACKERS] set_ps_display on solaris x86

>>>>> "Bruce" == Bruce Momjian <[EMAIL PROTECTED]> writes: Bruce> Tom Lane wrote: >> Sailesh Krishnamurthy <[EMAIL PROTECTED]> writes: >> > Sadly, set_ps_display does not seem to have any effect in solaris >> >

Re: [HACKERS] Detecting corrupted pages earlier

bits are set and some others are reset then you know that there was a corruption. This is of course based on the assumption that most disk arms manage to atomically write 256 bytes at a time. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

[HACKERS] some more docbook help

book-dsssl-1.77/html/dblink.dsl:203:1:E: XRef LinkEnd to missing ID 'STON89' openjade:/usr/local/share/sgml/docbook-dsssl-1.77/html/dblink.dsl:203:1:E: XRef LinkEnd to missing ID 'STON90b' gmake: *** [admin.html] Error 1 Does anybody have any suggestions ? Am I doing something horribly wrong ? Many thanks ! -- Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]

Re: [HACKERS] some more docbook help

e whole process of SGML documentation as separating content from presentation. So I imagine I should surround our new stuff with some kind of tag, that when used with an HTML (or other) stylesheet generates appropriately changed documentation. I hope I am on the right track ! Could somebody help me ple

Re: [HACKERS] Help needed in testing my code.

Why don't you use elog(LOG, instead of printf ? -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTE

Re: [HACKERS] Help needed in testing my code.

postmaster Srikanth> for example,pls tell what should i do after i add code, Srikanth> what make files should i run and where should i place Srikanth> the new executables. Well you sould start out by RTFM .. read how to build postgres. I run "make install" in my pos

Re: [GENERAL] [HACKERS] psql

web is based off of 7.2 code, but I hope to refresh with a beta based on 7.3 code in the next few weeks. http://telegraph.cs.berkeley.edu/telegraphcq -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 7: don't forget to increase your free space map settings

Re: [HACKERS] Two weeks to feature freeze

ssion test suite is great. We have clearing the pgsql regression test a checkin requirement for TelegraphCQ developers as our goal is to not break pgsql functionality. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--

Re: [HACKERS] Two weeks to feature freeze

s. (Although I guess in practice, many people use Presumed Abort and not vanilla 2PC as PA results in fewer log flushes for read-only transactions.) -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match

Re: [HACKERS] Two weeks to feature freeze

>>>>> "Tom" == Tom Lane <[EMAIL PROTECTED]> writes: Tom> Sailesh Krishnamurthy <[EMAIL PROTECTED]> writes: >> I'm not sure if I understand Tom's beef - I think he is >> concerned about what happens if a subordinate does no

Re: [HACKERS] 2PC: discussion in comp.arch

odebase with unnecessary complexity. Let's just not confuse "no need for XYZ functionality" with "XYZ functionality is lame and can never work in practice". -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html

[HACKERS] agg/order-by question

be descending ? It doesn't affect the Group and the Agg in any way .. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match

Re: [HACKERS] agg/order-by question

hat you lose the modularity of the sort. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html

[HACKERS] find_typedef on Linux

I need to pass to configure to ensure that all binaries are built appropriately ? That is, something _other_ than --enable-debug as I always have that anyways. Thanks ! -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)

[HACKERS] ANNOUNCEMENT: Availability of TelegraphCQ v0.2 (BETA release)

yet. We welcome patches that help in porting TelegraphCQ. Please send all comments (and patches) to [EMAIL PROTECTED] -- -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(e

Re: [HACKERS] table-level and row-level locks.

Once more unto the breach - Could you please abstain from sending HTML email to the list ? Many thanks ! -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ

Re: [HACKERS] this is in plain text (row level locks)

in his Ph.D. thesis in the mid-eighties for main-memory databases (where you don't take the write penalty). -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

Re: [HACKERS] this is in plain text (row level locks)

ves you more concurrency at some very minor overhead of not being strictly serializable). -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

Re: [HACKERS] this is in plain text (row level locks)

f the answer comes back Why do you want to query the lock manager as a separate process ? Why not have the traditional approach of a lock table in shared memory, growing and shrinking as appropriate, and have each individual process update it (need to protect it with a latch of course). -- Pip-pip S

Re: [HACKERS] this is in plain text (row level locks)

>>>>> "Tom" == Tom Lane <[EMAIL PROTECTED]> writes: Tom> Sailesh Krishnamurthy <[EMAIL PROTECTED]> writes: >> Why not have the traditional approach of a lock table in shared >> memory, growing and shrinking as appropriate, Tom&

Re: [HACKERS] this is in plain text (row level locks)

>>>>> "Tom" == Tom Lane <[EMAIL PROTECTED]> writes: Tom> Sailesh Krishnamurthy <[EMAIL PROTECTED]> writes: >> We implemented a Shared Memory MemoryContext using OSSP libmm >> (used in Apache) for TelegraphCQ. Tom> How po

Re: [HACKERS] this is in plain text (row level locks)

>>>>> "Bruce" == Bruce Momjian <[EMAIL PROTECTED]> writes: >> -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh Bruce> ^^^ Watch out, that code from Bruce> Berkeley usually is a mess. :-) LOL ! That's

Re: [HACKERS] this is in plain text (row level locks)

some experiments to measure the costs of our shared memory MemoryContext. Is there something specific you'd be interested in ? My first goal is mainly to measure the amount of time it takes to allocate and deallocate shared memory in the contested and uncontested cases. -- P

Re: [HACKERS] PostgreSQL not ACID compliant?

edicate locking to get true serializability without losing too much concurrency. While this falls short in the general case, it turns out to be pretty acceptable normally (when indexes are present). -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broad

Re: [HACKERS] how to add seconds to a TimestampTz

If you read the autovacuum_naptime into an Interval object once, why can't you just use timestamptz_pl_interval ? You won't be using the interval input/output repeatedly surely. Regards Sailesh -- Sailesh Krishnamurthy Amalgamated Insight [W] (650) 242-3503 [C] (650) 804-6585 ---

[HACKERS] Update on TelegraphCQ

gt;> for v.7.3.Is there any alternatives for the latest version of PostgreSQL ? > > The TelegraphCQ team has stopped public development. So it's > pretty much waiting for someone to take on their code. Regards Sailesh -- Sailesh Krishnamurthy Amalgamate

Re: [HACKERS] Call to build-in operator from new operator

se post on the tcq mailing list. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so

Re: [HACKERS] [pgsql-hackers-win32] Sync vs. fsync during

able >> space is small, as that the available space is fixed --- we >> can't easily change it after postmaster start. The more finely Again, I can suggest the shared memory MemoryContext we use in TelegraphCQ that is based on the OSSP libmm memory manager. We use it t

Re: [HACKERS] linked list rewrite

fine (and keep re-merging). Which brings me to another question .. has anybody considered using subversion instead of CVS ? -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 8: explain analyze is your friend

[HACKERS] Chapter on PostreSQL in a book

tion Tools I'm at a loss as to how much we should focus on these sections. Do we use what's in GBorg ? Do the hackers have any suggestions ? There are 33 DBA tools and 19 Design tools in GBorg .. are there any specific tools that are "recommended" ? Suggestions

Re: [HACKERS] subversion vs cvs

>>>>> "Marc" == Marc G Fournier <[EMAIL PROTECTED]> writes: Marc> On Tue, 23 Mar 2004, Sailesh Krishnamurthy wrote: >> Which brings me to another question .. has anybody considered >> using subversion instead of CVS ? Marc> Wh

[HACKERS] Position available at the Telegraph project

; also exposure to scripting languages such as PERL, PHP and their regular expression libraries. Requires an ability to install and maintain web servers and services. Exposure to the Database and/or Information Retrieval research literature is desirable. -------

Re: [HACKERS] proposal: be smarter about i/o patterns in index scan

is a lock against vaccuuming in the presence of a tid-list-fetch. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html

Re: [HACKERS] proposal: be smarter about i/o patterns in index scan

after, are how to deal with locking Tom> considerations and what will be the implications of giving up Tom> the property that indexscans deliver sorted output. I don't know about the former, but as to the latter, we should certainly have the ability for both output sorted b

[HACKERS] On query rewrite

y, does PG do a subquery to join transformation ? Thanks ! -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

Re: [HACKERS] On query rewrite

appen along with the transformations ? Alvaro> The query's path is SQL -> parse -> rewrite -> optimize -> Alvaro> execute Can you please point me to the code that indeed does such transformations ? -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

Re: [HACKERS] On query rewrite

pose after applying a rule the resultant query tree is eligible for another rule, does pgsql's rule system keep iterating over and over until it reaches a fixed point or is there some heuristic in operation (just apply the rules twice ..) ? From my cursory inspection of the code it looks like the l

Re: [HACKERS] On query rewrite

subquery because the upper query uses the subquery with existential quantification In general, I'm trying to understand all the transformations that pgsql will try to do .. I'm not trying to figure out plan enumeration for basic boxes (simple query tree). -- Pip-pip Sailesh http:/

Re: [HACKERS] On query rewrite

cular you Tom> probably want to look at prepjointree.c and prepqual.c. Tom> (Note prepqual also looks considerably different in CVS tip Tom> than in prior releases.) Thanks .. I've extracted cvstip .. sigh .. one of these days I'll have to do another merge with the Tel

Re: [HACKERS] Extended customizing, SQL functions,

LECT time takes a while. Then they have to pgsql> vacuum constanty. It just seems like an ugly and wastefull pgsql> process. Sounds like something that TelegraphCQ can do well .. http://telegraph.cs.berkeley.edu -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh

Re: [HACKERS] Why hash indexes suck

hich can do binary search to find an item within a page). This is probably a crazy idea, but is it possible to organize the data in a page of a hash bucket as a binary tree ? Then you wouldn't lose wrt CPU time at least. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh --

Re: [HACKERS] pulling projection up in plans

crude perf studies and found that it didn't really help if there was no sharing .. as is the case with pgsql). -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an

Re: [HACKERS] Database Kernels and O_DIRECT

Several operating system services are examined with a view toward their applicability to support of database management functions. These services include buffer pool management; the file system; scheduling, process management, and interprocess communication; an

Re: [HACKERS] Dreaming About Redesigning SQL

e it is true that some of XML db technology is evocative of network databases, XML databases are certainly more than network databases. For one, they are semi-structure .. in addition they present query language access to their data (although I'm not a big fan of XQuery). -- Pip-pip Sailesh http:/

Re: [HACKERS] Dreaming About Redesigning SQL

ot admit (at least in public :-) to being a big fan of XQuery but that is because of certain details, not anything fundamental. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org

Re: [HACKERS] Dreaming About Redesigning SQL

v 24 perhaps. I have a conference deadline .. the papers that we write "just to secure funding" - your tax dollars at work. Long live the NSF ! BTW, I'm not necessarily that far from your views. There is, however, more to an XML database than just storing data - relational databases

Re: [HACKERS] O_DIRECT in freebsd

DB2 supports cooked and raw file systems - SMS (System Manged Space) and DMS (Database Managed Space) tablespaces. The DB2 experience is that DMS tends to outperform SMS but requires considerable tuning and administrative overhead to see these wins. -- Pip-pip Sailesh http

Re: [HACKERS] O_DIRECT in freebsd

vantage provided you care enough to understand what's going on. Anyway, I merely responded to provide a data point. Will PostgreSQL users/administrators care for additional knobs or is there a preference for "keep it simple, stupid" ? -- Pip-pip Sailesh http://www.cs.b

Re: [HACKERS] Is there going to be a port to Solaris 9 x86 in the

based off of pgsql-7.3.2) -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])

Re: [HACKERS] Is there going to be a port to Solaris 9 x86 in the

upedAgg work for large numbers of unique values (by using a form of hybrid hashing). Another thing I toyed with was having an implementation of a Tid-List-Fetch .. sorting a TID-list from an index and fetching the records of the relation off the sorted list for better IO perform

Re: [HACKERS] Is there going to be a port to Solaris 9 x86 in the

division "Introduction to >> Database Systems" class .. >> http://www-inst.eecs.berkeley.edu/~cs186/ Chris> Hi Sailesh, Chris> You know what would be kind of cool? If you could write a Chris> "Guide to PostgreSQL to Teach Databases".

Re: [HACKERS] Is there going to be a port to Solaris 9 x86 in the

27;em buys you buffer cache locality. When there are large numbers of hits, it also buys you sequential scans where the file system prefetcher can help. The additional overhead you pay is the sorting cost. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org

Re: [HACKERS] Is there going to be a port to Solaris 9 x86 in the

tial Mike> device rather than a random access device." Mike> Isn't a TID-List-Fetch implementation a crucial first step in the Mike> right direction? I believe so .. I think it's a clear win. I believe there are some concurrency issues although I'm not sure

Re: [HACKERS] Is there going to be a port to Solaris 9 x86 in the

chime in. Marcel Kornacker did implement concurrency for GiST - I confirmed as much with Joe Hellerstein (his advisor). I know there's a paper he wrote with C.Mohan on it. I don't know which version his implementation was for. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sai

Re: [HACKERS] detecting poor query plans

at IBM Almaden. http://www.almaden.ibm.com/software/dm/SMART/leo.shtml There is a vldb paper that describes it .. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 7: don't forget to increase your free space map settings

Re: [HACKERS] Materialized views proposal

eliminating choices in your access plan. As people have said there are plenty of papers on this in the literature. While I am no theorist I can certainly help with reading the papers .. not every bit of a paper is very useful. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh

[HACKERS] relation_byte_size()

ourse, from a costing perspective these shouldn't be very different but ...) -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org

Re: [HACKERS] PostgreSQL port to pure Java?

Building the Telegraph Dataflow System. SIGMOD Record 30(4): 103-114 (2001) Apart from our group, the database research group in Wisconsin also rewrote their Niagara system from Java to C++. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast

Re: [HACKERS] OLAP CUBE/ROLLUP Operators and GROUP BY grouping sets

ignment. I was planning to clean it up and submit it properly but I never got the time) -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 8: explain analyze is your friend

Re: [HACKERS] Performance and WAL on big inserts/updates

pproach, is not a general solution. How would you handle the "update current of cursor" scenarios ? In this case, there is some application logic that determines the precise records that change and how they change. Ergo, it is my claim that while logical redo logg

Re: [HACKERS] Performance and WAL on big inserts/updates

pp has a lot of updates .. it's just that I'm not convinced that logical logging is a clean solution. I also don't have a solution for your problem :-) -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

Re: [HACKERS] Reducing expression evaluation overhead

should reduce the number of times ExecEvalVar (and through it heapgetattr) are called. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match

Re: [HACKERS] Reducing expression evaluation overhead

o the IHT. All this was only possible because you guys kept around the varnoold and the attnoold !! -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropria

Re: [HACKERS] APR 1.0 released

this can be done without threads .. you just need inter-process communication. (BTW, there is at least one commercial system that follows exactly this model). -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

Re: [HACKERS] beta1 & beta2 & Windows & heavy load

27;m inclined I think I've said it before, but we actually have such a beast - a shared memory MemoryContext that uses libmm (which apparently Apache also uses). It should be fairly easy to patch in if it's worth it for you folks. -- Pip-pip Sailesh http://www.cs.berkeley.

Re: [HACKERS] APR 1.0 released

' listed yet? As I Marc> recall it, until that gets done, parallelization of anything Marc> was considered to be a relatively onerous task, no? You don't really need to parallelize in separate threads .. you can have more than one process working on one query

Re: [HACKERS] APR 1.0 released

ano query processing system" By Goetz Graefe in SIGMOD 1990. Link: http://portal.acm.org/citation.cfm?id=98720 The above link also has references to Gamma but I really like the exposition in the Volcano/Exchange work much better. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~saile

Re: [HACKERS] plans for bitmap indexes?

>>>>> "Yann" == Yann Michel <[EMAIL PROTECTED]> writes: Yann> O.K. I downloaded it :-) We will see if and how I can Yann> help FYI .. in case you aren't aware already: http://portal.acm.org/citation.cfm?id=98720 -- Pip-pip S

Re: [HACKERS] plans for bitmap indexes?

even re-fetching from disk) the same heap page twice for a given index scan. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 8: explain analyze is your friend

Re: [HACKERS] plans for bitmap indexes?

eal sure that you will never kick out a page from the buffer cache .. I believe that for large enough tables this can certainly help .. it sure is something that many other systems have implemented. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broa

Re: [HACKERS] Much Ado About COUNT(*)

t maintaining visibility in indexes. Index-only plans are thus viable as they require no change in the physical structure of the index and no overhead on update/delete/insert ops. I don't know about Oracle, which I gather is the only commercial system to have som

Re: [HACKERS] Much Ado About COUNT(*)

approach to defining transaction isolation is "Generalized isolation level definitions" by Adya, Liskov and O'Neill that appears in ICDE 2000. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP

Re: [HACKERS] Group-count estimation statistics

where we use a hash table until we run out of memory at which time we start spilling to disk. In other words, no longer use SortAgg at all .. Under what circumstances will a SortAgg consumer more IOs than a hybrid hash strategy ? -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh

Re: [HACKERS] enforcing a plan (in brief)

- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match

Re: [HACKERS] Design notes for BufMgrLock rewrite

unnecessarily block other operations. -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 7: don't forget to increase your free space map settings

Re: [HACKERS] Query optimizer 8.0.1 (and 8.0)

Sounds a bit like multi-dimensional clustering ... http://www.research.ibm.com/mdc/ After the ARC experience though ... -- Pip-pip Sailesh http://www.cs.berkeley.edu/~sailesh ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster