The Art of PostgreSQL

The Art of PostgreSQL by Dimitri Fontaine is now available at https://theartofpostgresql.com. The book has several digital editions as well as a paperback edition.

As the new edition of the previously released Mastering PostgreSQL in Application Development, The Art of PostgreSQL updates content and comes with a new chapter about PostgreSQL extensions, such as hstore, pg_trgm, intarray, earthdistance, ip4r, and HyperLogLog, one of Craig Kerstiens' all time favorite extensions.

The Art of PostgreSQL will help you turn thousands of lines of code into simple queries.

Red Hat Announces CentOS Stream

Red Hat has announced a new Linux distribution called CentOS Stream for better synergy among RHEL (Red Hat Enterprise Linux), Fedora, and CentOS (https://lists.centos.org/pipermail/centos-announce/2019-September/023449.html).

CentOS is a clone of RHEL (minus Red Hat branding), which is compiled from the source code that Red Hat releases publicly. CentOS is funded by Red Hat but is a purely community driven project, though most lead developers of CentOS are employed by Red Hat.

CentOS Stream will sit somewhere between Fedora and RHEL to provide a place for developers who want to get their packages in RHEL. So far Fedora was used as a fast moving upstream project for RHEL. Red Hat forks code from Fedora to build the next version of RHEL. However, most enterprise-centric users were on CentOS and not Fedora, and there was not a direct path for those users to target RHEL, as CentOS was downstream of RHEL. With CentOS stream, developers can start playing with what to expect next in RHEL, and they can also submit patches.

"In practice, CentOS Stream will contain the code being developed for the next minor RHEL release. This development model will allow the community to discuss, suggest, and contribute features and fixes into RHEL more quickly," said Karanbir Singh, project leader of CentOS.

Linus Torvalds Agrees to Kernel Lockdown

Linus Torvalds has finally agreed to implement a lockdown feature for the Linux kernel (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=aefcf2f4b58155d27340ba5f9ddbe9513da8286d). The feature was proposed several years ago but was rejected by Torvalds.

The upcoming release of Linux, version 5.4, will include this feature as a Linux Security Module (LSM). It will have two lockdown modes: "integrity" and "confidentiality."

Torvalds explained that, "If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled."

According to ZDNet (https://www.zdnet.com/article/linux-to-get-kernel-lockdown-feature/), the new feature's primary function will be to strengthen the divide between userland processes and kernel code – even the root user will have limited access.

The feature will be disabled by default as it could lead to unexpected behaviors. Many Linux distributions, including Ubuntu and Red Hat have already implemented their own lockdown features using additional modules.