Tag Archives: database

Elasticsearch – Advance Query [Aggregations]

The from and size is almost like pagination. It will show 0 to 20 results.The sort is sorting the return data. What is happening here, it will use the query and fetch method. It will…

Elasticsearch – Advance Query [DSL Filter Context]

Filters don’t have relevance scores. And filters are cached, so queries that we have already run, elasticsearch is going to cached. The filter is faster than a query. A basic filter…

Elasticsearch – Advance Query [DSL Query Context]

DSL Query Context

The exists checks if the field email exists under the professor not that if there is any value exists or not.

Under the “must”…

Elasticsearch – Full Text Queries

In the previous section, we went through a number of term level queries, which are used for exact matches. While we can use term level queries for searching for long…

Elasticsearch – Searching and Querying

Searching with Request URI The query DSL is the most common approach. The way you issue a search request is to send a get request to the search API, then…

Elasticsearch – Mapping

In elasticsearch mappings are used to define how documents and its fields should be stored and indexed. The point of doing this is to store and index data in a…

Elasticsearch – Configuring and Managing Documents in Kibana

After kibana is up and running if you access http://localhost:5601, we will see the system is asking us to configure the index pattern. Here you can enter a pattern for…

mysql join and inner join

MySQL Join and Inner Join

OK now, let’s talk about joins. A SQL join combines columns from two or more tables in a single result set. You see MySQL is a relational database, and too…

Database Design in a Nutshell

Database design is a very extensive subject and I intent to build an entire course on that, but we need to understand at least a few basic things about database…

Tables, Columns and Rows

Tables, Columns and Rows

We can’t get too far in talking about any database management systems without discussing the concept of a table. And the constituent parts of table called columns and rows. So…