- developers-list - monetdb.org

[Monetdb-developers] Restart mclient
by Romulo Antonio Goncalves 07 Sep '10

07 Sep '10

Hello, I updated my default branch and I do the following: mclient -lmal >\q mclient -lmal >\q After the second exit I get a crash in the mserver: >[New Thread 0x7fffdf7ac710 (LWP 19441)] Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7fffdf7ac710 (LWP 19441)] 0x00007ffff7cd7198 in MALexitClient (c=0x605b38) at /ufs/goncalve/MonetDB/current/MonetDB5/src/mal/mal_session.mx:522 522 if (c->glb && c->curprg->def->errors == 0) (gdb) p c->curprg->def $1 = (struct MALBLK *) 0xdbdbdbdbdbdbdbdb Similar problem if you do mclient -lsql >\q mclient -lsql The mserver crashes due to the same problem: Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7fffdf7ac710 (LWP 19561)] 0x00007fffdfe22a60 in SQLparser (c=0x605b38) at /ufs/goncalve/MonetDB/current/sql/src/backends/monet5/sql_scenario.mx:1155 1155 oldvtop = c->curprg->def->vtop; (gdb) p c->curprg $5 = (Symbol) 0x7fffd8112198 (gdb) p *c->curprg $6 = {peer = 0xdbdbdbdbdbdbdbdb, skip = 0xdbdbdbdbdbdbdbdb, name = 0xdbdbdbdbdbdbdbdb <Address 0xdbdbdbdbdbdbdbdb out of bounds>, kind = -606348325, def = 0xdbdbdbdbdbdbdbdb} (gdb) Were there any changes in the client structure or in the initialization of the of the client threads? Regards, Romulo PS: It does not happen in the Oct2010 branch.

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[Monetdb-developers] How to enable functions via sql?
by Alexandr Kulik 06 Sep '10

06 Sep '10

Hi, I need to develop some extra statistical functions for MonetDB. I spent about a week to understand how to use function via sql, but still didn't have any succes results. May be someone could point me to appropriate documentation or source revision, where i could look on it? -- With Best Regards Alexandr Kulik Skype: kulya_u Yahoo: kulya_u LinkedIn: http://www.linkedin.com/in/alexandrkulik Mobile: +3(806)615-40511

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[Monetdb-developers] New Oct2010 stable branch created
by Sjoerd Mullender 03 Sep '10

03 Sep '10

I have created new stable branches for the next feature release. This branch was created in order to stabilize the code before the feature release. From now on *only* bug fixes may go to this new stable branch. I reserve the right to undo any changes that do not comply with this rule. I also reserve the right to admit changes that are not strictly bug fixes. The name for the branch is Oct2010. So in each of your stable checkout directories you can do hg pull hg update -rOct2010 to update to this new branch. -- Sjoerd Mullender

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[Monetdb-developers] About MonetDB/X100
by xixi 01 Sep '10

01 Sep '10

Dear all, Recently I read some papers about X100,and see that the performance of X100 is very good ,and better than MonetDB/sql, and have a better design,so I want to ask when will we can see the code of the X100 ,and use the X100? Best regards!

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[Monetdb-developers] Announcement: New Jun2010-SP2 bugfix release of MonetDB suite
by Sjoerd Mullender 30 Aug '10

30 Aug '10

The MonetDB team at CWI/MonetDB BV is pleased to announce the Jun2010-SP2 bug fix release of the MonetDB suite of programs. More information (including release notes) on this release is available at <http://monetdb.cwi.nl/Development/Releases/Jun2010/>. The download location is <http://dev.monetdb.org/downloads/>. -- Sjoerd Mullender

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[Monetdb-developers] Testing update performance of MonetDB
by Lukas Kircher 25 Aug '10

25 Aug '10

Hi, I'm currently writing my bachelor's thesis at the university of Konstanz about extending BaseX [1] with XQuery Update. I wanted to compare evaluation times between MonetDB and BaseX, as they have comparable table layouts, but am facing several problems. So far I read your manual that suggests to use functions to support caching, as well as limiting inserts to a single position in a document. Some papers provided insight too [2,3], still there are questions (hopefully I didn't miss anything on your mailing lists and I hit the right one): 1. General storage: In which way is free space reserved, if an updatable document via fn:add-doc(u, x, y, freeSpace) is added? Let's assume freeSpace = 10%. Does this mean that free space (equal to 10% of our document size) is allocated between all used pages on disk? Spoken clearly, one tenth of free space on every page? But this would be in conflict with the suggestion to limit inserts to a single position in a document... 2. Timing: What happens during the 'Print'...ing part when I use the '-t' flag for timings? Query time is amazingly fast, yet I experience unusually long printing times - even for a small test document. Increasing the free space variable (see question 1) results in even longer printing times, which is on one side perfectly understandable as more pages on disk are used (right?)... 3. Yet, on the other side empty space on disk should not be accessed? I expect there to be a balance between query performance and free space? Is there a rule of thumb I can apply to get the most out of MonetDB (regarding specific queries of course)? 4. Are there any general advises for testing update performance of MonetDB? I could gain some knowledge from a previous post on the developers list - yet I feel it's not enough to explain the results of my (yet immature) tests and to do your system justice ... Thanks for your help! Looking forward to your answer... Best regards, Lukas [1] www.basex.org [2] Updating the Pre/Post Plane in MonetDB/XQuery [3] MonetDB/XQuery: A Fast XQuery Processor Powered by a Relational Engine

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[Monetdb-developers] About MAL instrction and C-function
by 嘻嘻 23 Aug '10

23 Aug '10

Dear all, Recently, I am learning the MonetDB,I know that a MAL instrction is corresponding to a C-function. such as a MAL instrction algebra.select() is corresponding to ALGselectInclusive(); and the corresponding file is algebra.mal, for example, command select(b:bat[:any_1,:any_2], low:any_2, high:any_2, li:bit, hi:bit) :bat[:any_1,:any_2] address ALGselectInclusive comment "Select all BUNs that have tail values: {v| low <{=} v <{=} high}. Boundary inclusion is indicated separately. NIL boundary values have a special meaning. + low == nil means: no lower bound + high == nil means: no upper bound."; My question is ,in MonetDB souces code, how to corresponding the MAL to the C-function, how to implement it ? and how to transfer the parameter from MAL to C-function? Best regards!

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[Monetdb-developers] run mapi examples
by kun ren 19 Aug '10

19 Aug '10

dear all recently,I want to run mapi examples from /Monetdb-client/clients/src/examples/C/, it contains sample0.c ,sample1.c and so on. I read the Application Programming Interfaces of the Monetdb manual, and I use: gcc sample0.c 'monetdb-clients-config --cflags --lib' -lMapi -o sample0 to complie it,but it has errors, so I want to ask how I will complie the files? Best regards!

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[Monetdb-developers] about MAL instrction
by kun ren 18 Aug '10

18 Aug '10

Dear all, I use MAL interface to manipulate the BAT data, I use sql.bind(,,0) to get a BAT, and use io.print() to print the BAT content, but when I use bat.insert to insert one bun to the bat,but after the bat.insert(), I run io.print() to print the BAT,but the bat content is not changed，I use sql.bind(,,,,1) to get the insert BAT of the orinal bat， but it is null. I think it it about commit() ?? how I commit it ? do I think right? Best regards!

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[Monetdb-developers] about Using Mal
by kun ren 18 Aug '10

18 Aug '10

Dear all, Recently,I am using MAL,using mclient -l mal command, If I use sql, I write a SQL: select * from t1; while t1 has two column c1 and c2,type is int. I want to ask what the corresponding MAL of this sql, if I us mclient -l mal ,what mal will I will use to implement the select * from t1 Best regards!

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