How to avoid prefixing every table with schema name while creating new tables ?

Lets assume schema name is my_data. If we want to avoid prefixing every table with my_data while creating a new table, we can set it in the search_path.

 SET search_path TO my_data;

Now we can create a new table like this.

CREATE TABLE courses (
    id SERIAL PRIMARY KEY,
    course_name TEXT
);

By using the above code, courses table will be created in my_data by default.

What command we need to use to list all tables inside the specific schema ?

Suppose if the schema name is my_data, then we need to use the following command to list all the tables inside the my_data schema.

\dt my_data.*

Now, if you want to create a new table inside the my_data schema, we just need to prefix the table name with the schema name like this.

CREATE TABLE my_data.students (
    id SERIAL PRIMARY KEY,
    name TEXT NOT NULL,
    age INT,
    enrolled_on DATE DEFAULT CURRENT_DATE
);

This will create the students table inside the my_data schema.

What command we need to use to list all schemas in the current PostgreSQL Database ?

\dn

This command is used to list All Schemas in the current PostgreSQL Database along with their owners.

Example Output:

   List of schemas

    Name     |    Owner
-------------+-------------
 public      | test_user
 mydata      | postgres

The \dn command is a PostgreSQL-specific meta-command used inside the psql command-line interface.

The default schema is usually public. Generally we use /dn to check existing schemas.

error Error: unable to get local issuer certificate

The error “unable to get local issuer certificate” occurs because Yarn is failing to establish a secure connection due to SSL certificate issues.

Run the following command in your terminal to fix this issue

yarn config set strict-ssl false

After this run the following command

yarn install

If it works, then it is an SSL certificate issue.

Pine Script code for Relative Strength Index (RSI) Calculation

The Relative Strength Index (RSI) can be used for detecting overbought/oversold levels across different timeframes.

Suppose if we want to calculate 14-Period Relative Strength Index (RSI) for 5-minute timeframe, we need to use following pine script code.

rsi_calc = ta.rsi(close, 14)
rsi_5min = request.security(syminfo.tickerid, "5", rsi_calc)

ta.rsi(close, 14) is the built-in function of pine script to calculate 14-Period RSI value using the closing price.

request.security is a function in Pine Script used to retrieve data from different time frames or symbols.

syminfo.tickerid is for getting current symbol/ticker.

As of now we are using “5”, which gives data for 5 minute timeframe. if we want data for 1 minute we need to change it to “1”.

Finally we pass rsi_calc which gives calculated RSI value from the 5-minute timeframe.

Syntax of request.security is as follows

 request.security(symbol, resolution, expression)