Databases
System Design Interview Concepts – Database Sharding
What is Sharding or Data Partitioning?<p>Sharding (also known as Data Partitioning) is the process of splitting a large dataset into many small …
DatabasesHow can I submit an invoice using MySQL, Nodejs and ReactJS?
I want to develop an invoice on my application which my class diagram is :<p>I develop my application with ReactJS on the frontend, nodejs on the …
UnicodeOptimizing PostgreSQL on AWS
<b>When:</b> August 20 | 1:00 PM - 1:45 PM PT (4:00 PM - 4:45 PM ET)<p><b>Level 200 | Service Intro</b><p>It's increasingly popular to run PostgreSQL in the cloud - but …
PostgreSQLDocker-compose v3 not persisting postgres database
I'm having difficulty persisting postgres data after a docker-compose v3 container is brought down and restarted. This seems to be a common problem, …
MicroservicesHow to remove unconnected node properties in Neo4j
I'm new to Neo4j and I've created some nodes and relationships to see how it works, but now when I want to clear everything and start from scratch I …
CypherAccelerate Database Development and Testing on AWS
<b>When:</b> August 21 | 11:00 AM - 11:45 AM PT (2:00 PM - 2:45 PM ET)<p><b>Level 200 | Service How To</b><p>The cloud provides several opportunities to accelerate …
Cloud ComputingBig data tools for real-time sensor data
I want to learn something about real-time sensor data analysis. I have a lot of sensor data and data continue to come. I'm thinking use mongodb for …
Big DataSQL Express Connectionstring error when site moved to 3rd party hosting
I created an MVC 5 site locally that uses Identity. I eventually moved the connection string to point to a SQL Server on a 3rd party hosting server …
SQL ServersMeteor/Apollo: Set Up Redis Pubsub for Production?
I'm working on getting Redis Pubsub working in my Meteor app hosted on Galaxy.The Redis Pubsub docs say to initialize it this way:When I run:...I get …
JavaScriptCheck against multiple fields when using Mongoose Virtual schema?
I am a little stuck with trying to figure out the best way to populate a virtual schema in my db. In this instance, I want to check against multiple …
Databasesscala test failing - assertDataFrameEquals comparing null and NULL
One of my scala test is failing. I took the failed tuples and compared it side by side and noticed the comparison fails in a column with NULL values. …
DatabasesSQL select latest values in a pivot table
How can I select latest records in a pivot table with many-to-many relationship. The store_id,product_id is not a composite group key so they repeat …
SqlBigQuery commandline tool error: Try using the WRITE_TRUNCATE write disposition to replace the existing table
I got this error when I run bq upload command:But it is not very clear how to specify this. I think it should be specified in --job_property flag?But …
Command-lineCypher: Returning node relationships and properties for all nodes in a collection
Currently I'm running personalized PageRank over a set of nodes. I want to take the top n nodes and RETURN all relationships between these nodes <i>in</i> …
CypherElasticsearch field not showing up
I am new to ElasticSearch and I have added new field to index in elasticsearch. When I try to read documents in this index, I am not seeing new field …
ElasticSearchQuerying tables that consist of google sheets data, google big query
I have been trying to query from a temporary table (table definitions) that consists of google sheets data but I keep getting parse error in code.gs. …
AnalyticsARM access to the Gremlin Endpoint in Azure Cosmos DB
Is it possible to get access to the Graph / Gremlin endpoint for a Cosmos database using ARM so it can, for example, be set as an app setting?<p>You can …
Cloud Computinghow to add new entity from existing database in an existing DbContext in EF core 2 with npm?
I use NPM and scaffold-DbContext but every time i use -tables, other entities that i imported will be deleted and it is not like that the new table …
JavaScriptBlack Hat 2018 tools list
2018 Black Hat Conference<p>2018 Black Hat Conference<p>Android, iOS and mobile hackers<p>Vulnerable iOS app: Swift …
ForensicsHow to Sort Alphabetically in Word
Learning how to alphabetize in Word can save you loads of time and effort when you want to sort, organize, or classify text in tables, lists, or …
How-To'sStore 3 GB data in MongoDB Collection Document using GridFS in Spark-MongoDB Integration
I am totally new to MongoDB. I have taken a JSON file in Spark to MongoDB using Spark-MongoDB Connector.But the Input file size is around 2.3 GB When …
MongoDBIs there any problem if we rename the portgroup...
<b>1. Re: Is there any problem if we rename the portgroups created by NSX Manager?</b><p><b>jorge_luis_hernandez</b> Sep 30, 2016 3:22 PM (in response to …
NSXSet Session Timeout in days using SQL Server in ASP.Net MVC
I am trying to setup session timeouts in days for various roles for instance• Manager Role can have a session timeout set for 2 days<br>• CEO Role can have a …
SQL ServersNuke/Delete/Truncate Database entries after each test WITHOUT the use of data fixtures
I have the following test cases:Where I try to test the following method of a custom repository:So how after each test I will nuke all the database …
Reputation ManagementHow to Set Big Query Require Partition Filter in BQ Commandline
When Creating a new empty partitioned table schema in Big Query Web GUI, you can SET the <b>Require Partition filter</b> Option.• How can I set the same option …
Command-lineScala/Spark: How to select columns to read ONLY when list of columns > 0
I'm passing in a parameter fieldsToLoad: List[String] and I want to load ALL columns if this list is empty and load only the columns specified in the …
Ubiquitous ComputingBigQuery: Create a table from arrays
I want to create a table with two columns from two different arrays.Array1: [1,2,3]Array2: [11,12,13]Required Table:By using this query, I got 1 rowI …
Databasesusing unique isntead of primary key in table
I'm using Nhibernate into my project.But I curious about how to generate this code in Nhibernate using FluentMapping ALTER TABLE losing ADD …
DatabasesSorting datagrid by two columns removes the sort arrow [duplicate]
This question already has an answer here: • Flex: Database driven DataGrid: arrows disappearing 3 answers <br>I'm using Flex version 3.6 and I have a …
DatabasesOCI-04030: out of process memory when trying to allocate
Got the following error:OCI-04030: out of process memory when trying to allocate..While running an SSIS package using a batch file. What are the …
SQL Servers