Exploring New Features in PostgreSQL 17 with Python

PostgreSQL 17 brings a host of exciting new features and enhancements that cater to developers, data scientists, and database administrators. This article will explore some of the most significant additions and improvements in PostgreSQL 17 and demonstrate how to use these features with Python.

1. Improved Query Performance with Incremental Sort One of the standout features of PostgreSQL 17 is the enhancement of the incremental sort algorithm, which now supports a wider range of use cases. Incremental sort can significantly reduce the time taken to execute queries that involve large datasets, especially when dealing with sorted data.

Python Example: Incremental Sort with PostgreSQL 17

To use this feature, let's first set up a PostgreSQL connection using Python's psycopg2 library:

`import psycopg2

Connect to PostgreSQL database

conn = psycopg2.connect(
host="localhost",
database="test_db",
user="postgres",
password="your_password"
)

Create a cursor object

cur = conn.cursor()

Create a table and insert data

cur.execute("""
CREATE TABLE IF NOT EXISTS large_dataset (
id SERIAL PRIMARY KEY,
category VARCHAR(50),
value INT
);
""")

Insert sample data

cur.execute("""
INSERT INTO large_dataset (category, value)
SELECT
'Category ' || (i % 10),
random() * 1000
FROM generate_series(1, 1000000) i;
""")

conn.commit()

Using Incremental Sort

cur.execute("""
EXPLAIN ANALYZE
SELECT * FROM large_dataset
ORDER BY category, value;
""")

Fetch and print the query plan

query_plan = cur.fetchall()
for line in query_plan:
print(line)

Close the cursor and connection

cur.close()
conn.close()
`

In this example, PostgreSQL 17's improved incremental sort efficiently handles the ORDER BY clause, sorting data incrementally and reducing overall query execution time.

1. JSON Path Enhancements PostgreSQL 17 introduces enhancements to JSONPath, making it easier to query and manipulate JSON data. This is particularly useful for applications that heavily rely on JSON for data interchange.

Python Example: Using JSONPath Enhancements
`## Reconnect to the database
conn = psycopg2.connect(
host="localhost",
database="test_db",
user="postgres",
password="your_password"
)
cur = conn.cursor()

Create a table with JSON data

cur.execute("""
CREATE TABLE IF NOT EXISTS json_data (
id SERIAL PRIMARY KEY,
data JSONB
);
""")

Insert sample JSON data

cur.execute("""
INSERT INTO json_data (data)
VALUES
('{"name": "Alice", "age": 30, "skills": ["Python", "SQL"]}'),
('{"name": "Bob", "age": 25, "skills": ["Java", "C++"]}');
""")

conn.commit()

Query JSON data using JSONPath

cur.execute("""
SELECT data ->> 'name' AS name, data ->> 'age' AS age
FROM json_data
WHERE data @? '$.skills ? (@ == "Python")';
""")

Fetch and print the results

results = cur.fetchall()
for row in results:
print(row)

Close the cursor and connection

cur.close()
conn.close()
`

This code demonstrates how PostgreSQL 17’s enhanced JSONPath capabilities simplify extracting data from JSON fields based on complex conditions.

1. Enhanced Parallelism for Index Creation Index creation in PostgreSQL 17 is now more efficient due to improved parallelism, allowing for faster indexing on large datasets.

Python Example: Parallel Index Creation
`## Reconnect to the database
conn = psycopg2.connect(
host="localhost",
database="test_db",
user="postgres",
password="your_password"
)
cur = conn.cursor()

Create a large table

cur.execute("""
CREATE TABLE IF NOT EXISTS large_table (
id SERIAL PRIMARY KEY,
data VARCHAR(255)
);
""")

Insert a large number of rows

cur.execute("""
INSERT INTO large_table (data)
SELECT
md5(random()::text)
FROM generate_series(1, 5000000);
""")

conn.commit()

Create an index with parallelism

cur.execute("""
CREATE INDEX CONCURRENTLY large_table_data_idx ON large_table (data);
""")

conn.commit()

Close the cursor and connection

cur.close()
conn.close()
`

This example showcases PostgreSQL 17's improved ability to create indexes concurrently using multiple CPU cores, which is highly beneficial when working with massive tables.

1. SQL/JSON Standard Compliant Functions PostgreSQL 17 has added support for more SQL/JSON standard-compliant functions, enhancing its ability to handle JSON data with more SQL-standard syntax.

Python Example: SQL/JSON Standard Functions
`## Reconnect to the database
conn = psycopg2.connect(
host="localhost",
database="test_db",
user="postgres",
password="your_password"
)
cur = conn.cursor()

Create a table with JSON data

cur.execute("""
CREATE TABLE IF NOT EXISTS employee_data (
id SERIAL PRIMARY KEY,
info JSONB
);
""")

Insert sample JSON data

cur.execute("""
INSERT INTO employee_data (info)
VALUES
('{"name": "John", "department": "Sales", "salary": 5000}'),
('{"name": "Jane", "department": "IT", "salary": 7000}');
""")

conn.commit()

Query using SQL/JSON functions

cur.execute("""
SELECT jsonb_path_query_first(info, '$.department') AS department
FROM employee_data
WHERE jsonb_path_exists(info, '$.salary ? (@ > 6000)');
""")

Fetch and print the results

results = cur.fetchall()
for row in results:
print(row)

Close the cursor and connection

cur.close()
conn.close()
`

In this example, we demonstrate how to use SQL/JSON standard functions to query JSON data, showcasing PostgreSQL 17's compliance with new SQL standards.

For more information on PostgreSQL 17 and its new features, refer to the official documentation.