Hi,
Is there a special reason there are no i686 RPM's anymore like there
were until 4.6.0_rc2?
I think it's a bit weird there are RPM's for the hobby OS 'FedoraCore'
but not for the much used server OS 'RedHat Enterprise 3 (and 4)'?
The FedoraCore (which Core?) needs libstdc++.so.6 whereas RHEL 3 only
has libstdc++.so.5 ...
There also seems to be no SRPM's.
Cheers,
--
Henk van Lingen, Systems & Network Administrator (o- -+
Dept. of Computer Science, Utrecht University. /\ |
phone: +31-30-2535278 v_/_
http://henk.vanlingen.net/http://www.tuxtown.net/netiquette/
Howdy!
I'm looking to use the framework for high-performance storing
and querying of financial time series, i.e. ticks arriving
from the exchange. I need to be able to store 500-1000 (or more)
ticks per second and would like to be able to quickly find
similar time series given a date range.
I'm looking to create a cheaper alternative to www.kx.com
with their KDB and K language. For each tick I need to store
the datetime, symbol, trade type (bid/ask/trade), price and volume.
How would I do a similarity search? I would like to select
a portion of my stock chart (for example) and find subsequences
in other stocks that match the pattern.
What is the best way to take differences in scale be taken into account?
Would I need to calculate the Euclidian distance myself?
If I am to write wavelet or Fast Fourier Transform code,
should I write it in MIL or use the Python/Perl/etc interface?
Thanks for your help and please use the link in my signature
to read up on my project.
Thanks, Joel
--
http://wagerlabs.com/uptick
Dear all,
First my compliments with this piece of useful and implemented research.
Second I was wondering if there is a possibility to have so-called
"triggers" in MonetDB such as in for example PostgreSQL [1] or if there
are other ways to use MonetDB as an "active database".
If anyone has experiences in this field or can point me to the right
place to look for this experience I would be very thankful.
Kind regards,
Arthur van Bunningen
[1] http://www.postgresql.org/docs/8.0/static/triggers.html
--
Ir. A.H. van Bunningen - PhD Student, Data Management Technology
Univ. of Twente, Dept of EEMCS, POBox 217, 7500 AE Enschede, Netherlands
Email: bunninge(a)cs.utwente.nl, Phone: +31 53 489 4290, Room: ZI3061
WWW: http://www.cs.utwente.nl/~bunninge
Hi all,
Currently I've installed MonetDB & SQL on SUSE9.2 Pro from source as it was
in CVS on 15 July. The problem I have is that all my jdbc related tests fail
with a :
Database connect failed: Unable to connect (localhost:48016): Connection
refused
, MServer with sql option and MapiClient runs just fine. Another example :
% java -jar share/MonetDB/lib/MonetDB_JDBC.jar -umonetdb
password: <monetdb>
Currenlty also fails with the given username, password.
Is the documentation or are the tests outdated?
Or is there something I should be aware of before I can run the java part
correctly.
My main focus for MonetDB is also the usage of SQL by using a JDBC
connection, therefore I hope this isn't a known newbie problem.
cheers,
Arnold
Hi there,
I just spent several hours scratching my head over why a piece of code
didn't work. I was experimenting with Mapi and tried the example listed
on the top of this page:
http://monetdb.cwi.nl/TechDocs/APIs/Mapi/C/index.html
This contains the following line:
if ((hdl = mapi_query(dbh, "create table emp(name varchar, age
int)")) == NULL)
die(dbh);
Unfortunately, it needs to be 'varchar(20)', not just plain 'varchar'.
Just 'varchar' apparently does *not* result in an error, but instead all
subsequent insert operations plus the select operation do nothing
whatsoever; the fetching returns no results at all.
The combination of this very bad error reporting and the mistake in the
very first example given on the C API page cost me quite a bit of time,
so I'm slightly grumpy. :)
The bad example given is not good, but the way the error appears to be
completely ignored is worse; this is not good for debuggability. The
combination is terrible and not particularly conductive to the uptake of
MonetDB.
It may be of course that this bug is already fixed in CVS; I'm working
off the latest release.
Anyway, now that my test code finally works, I can hopefully make some
progress hooking up XQuery to a Python API. (this is an experiment, and
I realize the existing Python Mapi client code already ought to work,
but we'll see..).
Regards,
Martijn
Hi there,
I'm trying to figure out how to use mapi to do an xquery. I have been
able to shred documents (using MIL), but mapi with xquery is giving me
trouble.
Looking at the implementation of MapiClient, I see the following piece
of code which appears relevant:
/* xquery options are passed via the command string
(becomes first line of query) */
char *c = command ? command : XQuerydefaultMode;
char *t = strstr(c, "timing-") ? "" : mark ? "timing-"
: "";
char *d = strstr(c, "debug-") ? "" : trace ? "debug-" : "";
char *m = strstr(c, "-mapi") ? "" : "-mapi";
command = (char*) malloc(strlen(c) + 20);
sprintf(command, "%s%s%s%s\n", t, d, c, m);
as well as this code:
if (command) {
/* special code for XQuery: prepend command to query */
hdl = mapi_query_prep(mid);
CHECK_RESULT(mid, hdl, buf, break);
mapi_query_part(hdl, command, strlen(command));
what exactly is going on here? The logic is rather opaque... Is there
some minimal code example somewhere out there that shows how to do an
xquery using mapi?
Regards,
Martijn
Hi there,
Another question: does the xquery implementation have collection
support? It appears not, as fn:collection doesn't appear to be supported
yet, but I'm a newbie to xquery so I may be missing something.
I'm interested in XML content management applications, which tend to
keep lots (and lots) of smaller XML documents. It'd be interesting to be
able to query all of them (or sets of them) using XQuery in one go --
looping through all the stored documents and doing an XQuery on these
individually would be suboptimal.
Regards,
Martijn
