JSON vs JSONB differences in PostgreSQL - Visual Side-by-Side Comparison

Concept Flow - JSON vs JSONB differences

Store JSON as text

↓

Parse on read

↓

Slower reads

↓

Store JSONB as binary

↓

Parse on write

↓

Faster reads

↓

Supports indexing

JSON stores data as plain text and parses it when reading, while JSONB stores data in a binary format parsed on write, enabling faster reads and indexing.

Execution Sample

PostgreSQL

CREATE TABLE example (
  data_json JSON,
  data_jsonb JSONB
);

INSERT INTO example VALUES
('{"name": "Alice", "age": 30}', '{"name": "Alice", "age": 30}');

Creates a table with JSON and JSONB columns and inserts the same JSON data into both.

Execution Table

Step	Action	Data Stored	Parsing Time	Index Support	Query Speed
1	Insert JSON data	Text format	No parsing now	No	N/A
2	Insert JSONB data	Binary format	Parsing done now	Yes	N/A
3	Select JSON data	Text format	Parsing on read	No	Slower
4	Select JSONB data	Binary format	No parsing on read	Yes	Faster
5	Create index on JSONB	Binary format	N/A	Yes	Faster queries
6	Create index on JSON	Text format	N/A	No	No speedup
7	Query JSONB with index	Binary format	N/A	Yes	Fast
8	Query JSON without index	Text format	Parsing on read	No	Slow
9	End of demo	-	-	-	-

💡 Demonstrated JSON stores text parsed on read, JSONB stores binary parsed on write with indexing and faster queries.

Variable Tracker

Variable	Start	After Insert	After Select	After Index	Final
data_json	empty	text JSON stored	parsed on read	no index	slower queries
data_jsonb	empty	binary JSONB stored	no parse on read	index created	faster queries

Key Moments - 3 Insights

Why is JSON slower to query than JSONB?

Because JSON stores data as plain text and parses it every time you read it (see execution_table rows 3 and 8), while JSONB parses once on insert and stores in binary for faster access.

Can you create indexes on JSON columns?

No, JSON columns do not support indexing (execution_table rows 5 and 6). Only JSONB supports indexes, which speeds up queries.

Does JSONB store data exactly like JSON text?

No, JSONB stores data in a binary format that is not text but represents the same data structure, enabling faster operations (execution_table rows 2 and 4).

Visual Quiz - 3 Questions

Look at the execution_table, at which step is JSONB data parsed?

A Step 3 - Select JSON data

B Step 1 - Insert JSON data

C Step 2 - Insert JSONB data

D Step 4 - Select JSONB data

💡 Hint

Check the 'Parsing Time' column for JSONB insert step in execution_table row 2.

According to variable_tracker, what happens to data_jsonb after index creation?

A It remains unindexed and slow

B An index is created and queries become faster

C It is parsed on every read

D It converts back to text format

💡 Hint

Look at the 'After Index' and 'Final' columns for data_jsonb in variable_tracker.

From the execution_table, why is querying JSON slower than JSONB?

A Because JSON is parsed on read every time

B Because JSON supports indexing

C Because JSON is stored in binary

D Because JSONB stores text

💡 Hint

See the 'Parsing Time' and 'Query Speed' columns for JSON in execution_table rows 3 and 8.

Concept Snapshot

JSON stores data as plain text and parses it on every read.
JSONB stores data in a binary format parsed once on write.
JSONB supports indexing, making queries faster.
Use JSONB for better performance and indexing.
Use JSON if you need exact text preservation.

Full Transcript

This visual execution compares JSON and JSONB in PostgreSQL. JSON stores data as text and parses it each time you read it, which slows queries. JSONB stores data in a binary format parsed once when inserted, enabling faster reads and supporting indexes. The execution table shows steps inserting and selecting data, highlighting parsing times and indexing support. Variable tracking shows how data_json remains text and unindexed, while data_jsonb is binary and indexed. Key moments clarify why JSON is slower, why JSONB supports indexes, and how JSONB stores data differently. The quiz tests understanding of parsing steps, indexing effects, and query speed differences. The snapshot summarizes key points: JSON is text and slower, JSONB is binary, indexed, and faster. Choose JSONB for performance and indexing, JSON for exact text needs.