Tag: column

Feed: R-bloggers. Author: Daniel Weiland. Daniel Weiland – Consultant Medical Microbiologist – Newcastle upon Tyne NHS Foundation Trust Hello! This is my first blog post for the NHS R Community, which I stumbled across in the course of my work as a consultant medical microbiologist at Newcastle upon Tyne Hospitals NHS Foundation Trust. At work, I’ve been trying to use R to create column charts featuring 95% confidence intervals. I approached the friendly people on the NHS R Community’s Slack channel for further information and guidance. I must add here that the Community’s Slack channel has been extremely helpful to ... Read More

Feed: Planet MySQL; Author: MyDBOPS; To copy the data of the particular column of the table to another table/server, We have an option to export the data as CSV and import the data back to a different table. But when the table size is large and we need to copy the data only for the required data to the target table will cause the load in the server since the table scanning is huge. To overcome this, we have the pt-archiver copy the data from the source table to the destination as a whole or only for required columns. And ... Read More

Feed: Alation. Author: Talo Thomson. November 18, 2021 — Talo Thomson, Head of Content Marketing, Alation: Hi Jason, thanks for taking the time to speak with me. Which 21.4 update are you most excited about? Jason Ma, Senior Director of Product Management, Alation: Of course, Talo, happy to speak with you. With this release, we’ve made some nice enhancements to our data lineage capabilities. We’ve invested in two areas to help our customers get more lineage into the data catalog. First, we enhanced our automated lineage capabilities. Second, we created a process to empower those with tribal knowledge to curate ... Read More

Feed: Planet MySQL; Author: Dave Stokes;     Multi column indexes are a powerful way to speed up queries but they are often misunderstood.  In most other databases an index on columns a, b, and c can only be used when searching on columns (a,b,& c), (a & b), and (a)  -- according to the manual. Also that index supposedly can not be used to search for (b & c) or just (c).  Well, that is the way I learned it and the way I have been teaching it. But I was wrong!  Now would be a good time to read the ... Read More

Feed: R-bloggers. Author: sang-heon lee. [This article was first published on K & L Fintech Modeling, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here) Want to share your content on R-bloggers? click here if you have a blog, or here if you don't. This post makes a useful wrapper R function merge() for left outer join, which preserves the orders of row and column of input x data. It is not a must but useful when we prefer these fixed orders in some case. Left Outer Join which we try to do ... Read More

Feed: Recent Announcements. Amazon Web Services, Inc. (AWS), an Amazon.com company (NASDAQ: AMZN), extends Automatic Table Optimization to modify column compression encodings. This new capability maintains the optimal compression encodings in Amazon Redshift database tables on an ongoing basis to achieve high performance and reduce the storage utilization. By using automation to manage column compression, customers can ensure that column compression encodings are always optimized in order to get the best possible performance. A compression encoding specifies the type of compression that is applied to data values in a column as rows are added to a table. Choosing the right ... Read More

Feed: Recent Announcements. Amazon Redshift, a fully-managed cloud data warehouse, now supports case-insensitive collation with column and expression level overrides. Starting today, you can use the COLLATE clause within a CREATE DATABASE statement to specify the default collation for all CHAR and VARCHAR columns in the database as case-sensitive or case-insensitive. You can also specify a COLLATE clause in a CREATE TABLE statement to specify collation for columns in that table. In addition, the COLLATE() function allows you to override the collation of a string column or an expression. Collation is a set of rules that defines how database engines ... Read More

Feed: Planet PostgreSQL. This blog is about my work on the Postgres open source database, and is published on Planet PostgreSQL. PgLife allows monitoring of all Postgres community activity. Jsonb Multi-Column Type Casting Monday, May 3, 2021 I already covered jsonb type casting of single values. However, if you are extracting multiple values from jsonb that casting method can be cumbersome, and it also has limitations. Fortunately, there is another way — a way to retrieve multiple jsonb or json values and cast everything in one location. Here is a simple table taken from my previous blog post: CREATE TABLE ... Read More

Feed: Planet PostgreSQL. Contributing author David YouattAn underappreciated element of PostgreSQL performance can be the data types chosen and their organization in tables. For sites that are always looking for that incremental performance improvement, managing the exact layout and utilization of every byte of a row (also known as a tuple) can be worthwhile. This is an important consideration for databases that are migrating from other databases to PostgreSQL as the data types available in PostgreSQL and how they are laid out is unlike many other platforms ... Read More

Feed: Planet PostgreSQL. Every so often, on irc, someone asks how to get value from column that is passed as argument. This is generally seen as not possible, as pl/PgSQL doesn't have support for dynamic column names. We can work around it, though. Are the workarounds usable, in terms of performance? To test it, I will need some sample data. This doesn't have to be big, but let's make it big enough so that I can test performance within Pg itself. Let's say 10 million rows. =$ CREATE TABLE test ( id int4 generated always AS IDENTITY PRIMARY KEY, payload ... Read More