February 2022 - users-list

[MonetDB-users] Proofreading your professional documents
by Richard Hounslow 24 Feb '24

24 Feb '24

Dear Professor/Lecturer Please excuse us for contacting you directly. We are offering an efficient service to help you ensure your academic and professional work is written in perfect English. We will check the grammar and style of your work and return it to you to meet your requirements and deadlines. Proof-Reading-Service.com can provide you with a professional proofreading service at a very reasonable rate. All our proofreaders are highly qualified native English speakers. Many work as leading academics in their fields and all have extensive experience of proofreading to the highest standards. If you are interested in our service, please take a look at our website: www.proof-reading-service.com All you have to do is send us your document as a word attachment with the deadline and we will guarantee delivery of a perfectly written document to give you complete confidence when you submit your work. The fee is worked out on a flat rate (£6.95 per thousand words or 0.695 pence per word), so you know exactly how much the proofreading will cost in advance. Once we have received your document(s) we will confirm the word count, the price and the deadline. If you have not heard from us within 2 hours during normal business hours after you have sent your work please resend it from a different email account or send the file to proofreadings(a)gmail.com. We look forward to hearing from you! Yours faithfully Proof-Reading-Service.com

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Iterations in MonetDB
by Oxana Dolmatova 23 Feb '22

23 Feb '22

Hello MonetDB Team, I want to integrate iterations into MonetDB using the barrier symbols provided by MAL (here the variable list_of_updates is repeated body of the iteration and ex_cond is the exit condition): ======================================= res_body = stmt_list(sql->sa, list_of_updates); stmt *s_begin = stmt_begin(sql->sa); list_append(res_list, s_begin); list_append(res_list, ex_cond); stmt *s_check = stmt_check(sql->sa, ex_cond, s_begin); list_append(res_list, s_check); list_append(res_list, res_body); list_append(res_list, stmt_redo(sql->sa, s_check)); list_append(res_list, stmt_exit(sql->sa, s_begin)); return stmt_list(sql->sa, res_list); ======================================== Currently the implementation works, when the exit condition is true, but unfortunately never stops, if the exit condition is false (I assume that this happens due to non-updating computation of ex_cond). Could you please give the reference point in the documentation or code where I could look to check if my assumption is correct? Or point me to a proper mailing-list if this is the wrong one for such questions? :) Thank you and best regards, Oksana

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Fwd: COPY SELECT INTO with problems on new version 11.43.5 (Jan2022)
by Ariel Abadi 16 Feb '22

16 Feb '22

Hi All! I'm resending to the new user list. BR Ariel ---------- Forwarded message --------- From: Ariel Abadi <aabadi(a)starbi.com> Date: Fri, Feb 4, 2022, 18:44 Subject: COPY SELECT INTO with problems on new version 11.43.5 (Jan2022) To: Communication channel for MonetDB users <users-list(a)monetdb.org> Hi All! We found a problem on the new version 11.43.5 (Jan2022). We have some processes that run the COPY SELECT INTO to "move" data from monetdb to other different databases. We are expecting to receive an "answer" from monetdb affected, when the export finishes, like in the example below that informes "3 affected rows" sql>COPY SELECT * FROM cars INTO '/tmp/cars_out.csv' USING DELIMITERS ',' , '\n' , '"';*3 affected rows* While we run the same query on the new server, mclient/monetdb is not returning anything like the image below. sql>COPY SELECT * FROM cars INTO '/tmp/cars_out.csv' USING DELIMITERS ',' , '\n' , '"'; sql> Does anybody have the same issue? Am i doing something wrong? Thks a lot in advance! Ariel

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Announcement: New Jan2022-SP1 Bugfix release of MonetDB suite
by Sjoerd Mullender 14 Feb '22

14 Feb '22

The MonetDB team at MonetDB Solutions BV is pleased to announce the Jan2022-SP1 bugfix release of the MonetDB suite of programs. More information about MonetDB can be found on our website at <https://www.monetdb.org/>. For details on this release, please see the release notes at <https://www.monetdb.org/documentation/admin-guide/release-notes/jan2022/>. As usual, the download location is <https://www.monetdb.org/downloads/>. ### SQL Frontend - [This feature was already released in Jan2022 (11.43), but the ChangeLog was missing] Added SQL procedures sys.vacuum(sname string, tname string, cname string), sys.vacuum(sname string, tname string, cname string, interval int), sys.stop_vacuum(sname string, tname string, cname string). These can be used to vacuum string columns. ### Bug Fixes - [7228](https://github.com/MonetDB/MonetDB/issues/7228): COMMIT: transaction is aborted because of concurrency conflicts, will ROLLBACK instead - [7230](https://github.com/MonetDB/MonetDB/issues/7230): Prepared statement of INSERT with SELECT fails when types difer - [7232](https://github.com/MonetDB/MonetDB/issues/7232): False conflicts when inserting in a not null field - [7237](https://github.com/MonetDB/MonetDB/issues/7237): SELECT with concurrent writes rarely returns corrupt data - [7238](https://github.com/MonetDB/MonetDB/issues/7238): query with system function: "index"(varchar, boolean) fails with GDK error or assertion failure. - [7241](https://github.com/MonetDB/MonetDB/issues/7241): Replacing a view by a query on the view itself crashes the server.

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mailing list software updated
by Sjoerd Mullender 10 Feb '22

10 Feb '22

I have updated the mailing list software on monetdb.org from mailman2 to mailman3. This means that the old accounts for managing list subscriptions do not work anymore. In order to manage your subscription using a web interface, you will need to create a new account at https://www.monetdb.org/lists/. You can associate multiple email addresses to this account and manage all your subscriptions at monetdb.org using a single account, even if they use different email addresses. Unlike in mailman2, in mailman3 the passwords are not saved in plaintext, and therefore they cannot be sent as a monthly reminder. Mailing list archives have been converted to the new system as well. The old web addresses (https://mail.monetdb.org/, https://www.monetdb.org/mailman/ and https://www.monetdb.org/pipermail/) now all get redirected to the new interface. -- Sjoerd Mullender

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None
by None 10 Feb '22

10 Feb '22

keeping the BAT open (I always use "bat("name").XXX", or keep a ref variable in a block. So, as far as I can tell, I should not have 7500 BATs open at once. Am I misunderstanding? Or is there some underlying component/module keeping the BATs open? Or is this just the amount of memory MonetDB will use? I do not have a BAT of BATs (as I was sure that this would cause problems, and from your description, will indeed). Thanks! Ed

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None
by None 10 Feb '22

10 Feb '22

columns in a BAT (ie, BAT[OID, any]), is this just the first BUN? For update operations, does this mean that in the middle of inserting into a set of BATs, that as the BUN count is different, a concurrent query may not realize that the two BATs are synced? (this gets back to multiple client isolation for changes) Thanks for your time! Regards! Ed

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None
by None 10 Feb '22

10 Feb '22

"This is implemented by storing a very large OID for each column. An update to the column destroys this OID."

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None
by None 10 Feb '22

10 Feb '22

"For BAT-sets that contain exactly the same sets of OIDs, those OID-columns can be marked synced(). This information is then used to use positional lookup (the i-th element in BAT1 corresponds with the i-th in BAT2) and to turn semijoin- into very cheap copy-operations, etc." almost makes it sound as if you need synched() to actual test and set this bit. Is this true? How is the "syncedness" ensured when I have a BAT[OID, any], or determined?

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New MonetDB JDBC driver v3.2 and JdbcClient released
by Martin van Dinther 03 Feb '22

03 Feb '22

The MonetDB team at MonetDB BV is pleased to announce a feature release of the MonetDB JDBC driver (monetdb-jdbc-3.2.jre8.jar) and JdbcClient CLI program (jdbcclient.jre8.jar). The new release adds the capability to use the SQL: COPY ... INTO ... ON CLIENT statements via Java from the client side. This allows users and programmers to use the much faster COPY statements to load large data sets into MonetDB from a local client side CSV file or stream. The JDBC MonetConnection API has been extended with methods to register and use Upload and Download Handlers to stream the data from the Java client application to the server and/or from the server to the Java client. See <https://www.monetdb.org/downloads/Java/onclient.txt> for details. The new functionality has also been added to the JdbcClient CLI program, so you can now also use COPY ... INTO ... ON CLIENT statements from this CLI program, provided you have started it with a --csvdir argument. The CSV data files may also be gzip compressed (file name ends with: .gz). Besides this new functionality we also improved both the JDBC driver and JdbcClient to work optimal with the new MonetDB Jan2022 server release. For a list of all changes please read: <https://www.monetdb.org/downloads/Java/ChangeLog>. We recommend all users of MonetDB JDBC driver and/or JdbcClient program to upgrade to this new release. Especially if you use the new MonetDB Jan2022 server release, you should use the new jar files. The download location is as usual: <https://www.monetdb.org/downloads/Java/>. For information and tips on using the MonetDB JDBC driver, read: <https://www.monetdb.org/downloads/Java/release.txt>. Reminder: as of release monetdb-jdbc-3.0.jre8.jar the MonetDB JDBC Driver class name has been changed to: org.monetdb.jdbc.MonetDriver It used to be nl.cwi.monetdb.jdbc.MonetDriver which is marked as deprecated. Please use the new driver class name asap in your configuration files/scripts and/or Java code. The old driver class name is currently still included in the jdbc jar file but only to ease the transition for existing deployments. The old driver class will be removed in a future release of the MonetDB JDBC driver.

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