Feed: Planet MySQL; Author: Mark Callaghan; While trying to reproduce a MyRocks performance problem I ran a test using a 4gb block cache and tried both jemalloc and glibc malloc. The test server uses Ubuntu 16.04 which has glibc 2.23 today. The table below lists the VSZ and RSS values for the mysqld process after a test table has been loaded. RSS with glibc malloc is 2.6x larger than with jemalloc. MyRocks and RocksDB are much harder on an allocator than InnoDB and this test shows the value of jemalloc. VSZ(gb) RSS(gb) malloc    7.9     4.8    jemalloc-3.6.0 ... Read More

Feed: Planet MySQL; Author: Peter Gulutzan; Let's start by combining one new MariaDB feature -- VALUES (5) which is the standard equivalent of the old non-standard "SELECT 5" -- with another new feature in MariaDB 10.3.5, the FOR ... END FOR statement. mariadb>BEGIN NOT ATOMIC > DECLARE v INT DEFAULT 0; > FOR a IN (VALUES (7)) DO SET v = v + 1; END FOR; > SELECT v; >END; Error 2013 (HY000) Lost connection to MySQL server during query Oops. However, the MariaDB folks now know about this, it's bug MDEV-15940" and they know about the other bugs that ... Read More

Feed: Planet MySQL; Author: Michael McLaughlin; Encountered a problem while running the RODBC library from the R prompt as the root user, as follows: > install.packages('RODBC') It failed with the following library dependency: checking for unistd.h... yes checking sql.h usability... no checking sql.h presence... no checking for sql.h... no checking sqlext.h usability... no checking sqlext.h presence... no checking for sqlext.h... no configure: error: "ODBC headers sql.h and sqlext.h not found" ERROR: configuration failed for package ‘RODBC’ * removing ‘/usr/lib64/R/library/RODBC’   The downloaded source packages are in ‘/tmp/RtmpdT1gay/downloaded_packages’ Updating HTML index of packages in '.Library' Making 'packages.html' ... done Warning message: ... Read More

Feed: Planet MySQL; Author: MySQL Performance Blog; Laurie Coffin  | April 20, 2018 |  Posted In: AWS, Containers, Database Monitoring, MariaDB, MongoDB, MySQL, MySQL 8.0, open source databases, Percona Live PREVIOUS POST It’s hard to believe Percona Live 2018 starts on Monday! We’re looking forward to seeing everyone in Santa Clara next week! Here are some quick highlights to remember: In addition to all the amazing sessions and keynotes we’ve announced, we’ll be hosting the MySQL Community Awards and the Lightning Talks on Monday during the Opening Reception. We’ve also got a great lineup of demos in the exhibit hall all day ... Read More

Feed: R-bloggers. Author: R Views. I was surprised by greta. I had assumed that the tensorflow and reticulate packages would eventually enable R developers to look beyond deep learning applications and exploit the TensorFlow platform to create all manner of production-grade statistical applications. But I wasn’t thinking Bayesian. After all, Stan is probably everything a Bayesian modeler could want. Stan is a powerful, production-level probability distribution modeling engine with a slick R interface, deep documentation, and a dedicated development team. But greta lets users write TensorFlow-based Bayesian models directly in R! What could be more charming? greta removes the barrier ... Read More

Feed: R-bloggers. Author: Appsilon Data Science Blog. Semantic dashboard is on! Are you fed up with ordinary shinydashboard look? Give your app a new life with Semantic UI support. It cannot be any easier! Install semantic.dashboard and load it instead to your app. It’s compatible with classical shinydashboard! You don’t have to start from scratch: ######################### library(shinydashboard) # ui dashboardPage( dashboardHeader(title = "Basic dashboard"), dashboardSidebar(sidebarMenu( menuItem(tabName = "home", text = "Home", icon = icon("home")), menuItem(tabName = "another", text = "Another Tab", icon = icon("heart")) )), dashboardBody( fluidRow( box(plotOutput("plot1", height = 250)), box( title = "Controls", sliderInput("slider", "Number of observations:", 1, ... Read More

Feed: R-bloggers. Author: R on Rob J Hyndman. In late June, I will be in New York to teach my 3-day workshop on Forecasting using R. Tickets are available at Eventbrite.This is the first time I’ve taught this workshop in the US, having previously run it in the Netherlands and Australia. It will be based on the 2nd edition of my book “Forecasting: Principles and Practice” with George Athanasopoulos. All participants will get a print version of the book. Related To leave a comment for the author, please follow the link and comment on their blog: R on Rob J ... Read More

Feed: Planet MySQL; Author: Open Query; Sometimes you want to reduce disk usage on certain servers by adjusting the time that binary logs are kept.  Also, some installations of MySQL and MariaDB have suffered from a very-hard-to-catch bug where the binary logs end up not getting automatically expired (basically, the expire_logs_days option doesn’t always work effectively). A workaround can be scripted, but typically the script would specify the exact datetime to which the logs need to be kept.  The reference manual and examples all do this too, quite explicitly, noting: The datetime expression is in the format ‘YYYY-MM-DD hh:mm:ss’. However, ... Read More

Feed: Planet MySQL; Author: MySQL Performance Blog; Dave Avery  | April 23, 2018 |  Posted In: MariaDB, MongoDB, MySQL, Percona Live, PostgreSQL PREVIOUS POST Announcing the Percona Live 2018 live stream. This year at Percona Live Open Source Database Conference 2018 we are live streaming the Keynote Talks on Day 1 and 2. Percona is streaming the keynotes on Tuesday, April 24, 2018, and Wednesday, April 25, 2018 beginning at 9 AM PDT (both days). The keynote speakers include people from VividCortex, Upwork, Oracle, Netflix and many more. The keynote panels feature a cloud discussion and a cool technologies showcase. Use the live stream link if you don’t want ... Read More

Feed: Planet MySQL; Author: Tony Darnell; MySQL Enterprise Edition Database Firewall – Control and Monitor SQL Statement Executions April 23, 2018 Leave a comment As of MySQL 5.6.24, MySQL Enterprise Edition includes MySQL Enterprise Firewall, an application-level firewall (it runs within the mysql database process) that enables database administrators to permit or deny SQL statement execution based on matching against whitelists of accepted statement patterns. This helps harden MySQL Server against attacks such as SQL injection or attempts to exploit applications by using them outside of their legitimate query workload characteristics. Each MySQL account registered with the firewall has its own ... Read More