February 2022 - developers-list

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

does, however, like M4 still have the strange behaviour to be slower on PreparedStatements. When swithing from server side prepared statements, to Java emulated prepared statements, the performance goes to the same level as simple batched statements, while Java wise, the emulated version is much more computational extensive. I'm under the impression that for update queries we have around the absolute minimum of data sent over at this moment, hence the 'gap' we have with MySQL must be in the engine and/or the driver. For the latter I will have to investigate where shortcuts can be made, or inefficient structures are being used (such as very frequent Map lookups with few entries). This benchmark only tests update queries (inserts, updates, deletes), hence there is a need to revive a select based benchmark, or create one to get an idea how we perform in other use cases. A conclusion from the latest improvements is that searching for newlines appears to be expensive in both Java as well as C. (Smack tests showed a 10x speedup). Future improvements on these responses from the server that are a tabular result can be: - change header format for easier parsing (I don't expect much from this) - replace newlines by integer lengths to avoid string scanning - make parsing of tabular results easier/less expensive by avoiding string escaping

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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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