Postgres allows us to query the data of an entire array or a specific index of an array. Example 1: Querying Entire Array To query an entire array, the SELECT statement can be used. For instance, in the following snippet, the SELECT statement is used to query the “st_email” array: ...
PostgreSQL is a critical point in your infrastructure, as it stores all of your data. This makes visibility mandatory, which in turn means you have to understand how logging works in PostgreSQL. With the help of the logs and metrics that PostgreSQL provides, you can achieve visibility. In thi...
PostgreSQL, is an open-source RDBMS that allows you to store or manage data in structured formats, using rows and columns. It also allows for semi-structured data management like JSON files and XML documents. One can query JSON data with Postgres, pull out individual values from it, and eve...
PostgreSQL's ability to seamlessly integrate structured relational data with the flexibility of unstructured JSON data offers developers a unique advantage. By understanding how to query JSON columns effectively, one can harness the full potential of Postgres, making it easier to manage, retrieve, and ...
1. DISTINCT is a reserved keyword in PostgreSQL, so we cannot specify it as an object name. postgres=# create table distinct(n int); ERROR: syntax error at or near "distinct" 2. In a SELECT query we cannot have more than one DISTINCT keyword: ...
The output snippet proves that the “example_db”database has been renamed to “modified_db”. How to Rename a Database in PostgreSQL Using pgAdmin If you are a GUI lover and want to rename a database without executing any query, then opt for the pgAdmin(GUI-based development platform for...
Learn how to find slow queries in PostgreSQL using logs and metrics. Tutorial on how to check for and fix performance issues to speed up your database.
I need to delete all rows from table A which don't have corresponding data in table B and C meaning to delete (p1,p2,v1) from A if there is no (p3,p1,q1) in B and (p2, q1, v2) in B for any q1 and v2. Currently the query is: DELETE FROM A where concat(P1, P2) NOT...
We have also used like query when we have only remembered the half sting; using half string, we can find the whole string using like query in PostgreSQL. We can also use limit condition with a like query in PostgreSQL. We need to specify the case sensitive string while using like query ...
# service postgresql reload 1. Go to the directory where the logs of PostgreSQL are (comonly located in /var/lib/pgsql/data/pg_lo) and look for the lasted log file created. Below, you will find an example of a query that took more than 500ms: ...