Updated May 26, 2023
Introduction to PostgreSQL JSON vs. JSONB
PostgreSQL’s JSON is a data type that stores data as text according to the JSON rules, where JSON stands for ‘Javascript Object Notation’. JSONB does not involve any additional processing; instead, it directly copies the data in a manner similar to the JSON input text. On the other hand, when working with JSON, the processing function undergoes reparsing in each execution.
PostgreSQL’s jsonb is a JSON data type that stores data in a binary format, where jsonb stands for ‘Javascript Object Notation Binary’. JSONB experiences a relatively slower data input compared to JSON due to the requirement of conversion before storage. However, once stored in binary form, JSONB offers significantly faster processing speed. Hence, the overall efficiency is excellent in the case of JSON data type.
Comparison Table of PostgreSQL JSON vs JSONB
Below given is the comparison table showing the head to head comparison between JSON and jsonb in PostgreSQL:
|
S.No. |
PostgreSQL json |
PostgreSQL jsonb |
| 1 | JSON data type stores the exact copy of input text in JSON. | Jsonb stores the data as binary code. It stores the data in binary form, not an ASCII/ UTF-8 string. |
| 2 | Json preserves the original formatting, like the whitespaces as well as the ordering of keys. | Jsonb does not preserve the original text formatting, like the whitespaces and the ordering of keys. |
| 3 | Json processes input faster than jsonb because it doesn’t involve any conversion. | Jsonb converts the JSON data into the binary form, so it has slightly slower input due to the binary conversion overhead. |
| 4 | There is no change in the Schema design while working with JSON. All the entities, attributes, and values remain the same. | Schema designs are comparatively easier than Json as it replaces the entity- attribute value with jsonb blob columns, which are easier to query. |
| 5 | JSON data does not take much disk space as the JSON data is stored as it is. | More disk space is required for jsonb data as compared to JSON data type. |
| 6 | The processing function needs to be reparsed in each execution when the input text is in JSON data type. | In the case of jsonb, processing the data is comparatively faster because it doesn’t require reparsing. |
| 7 | JSON does not support indexing, unlike jsonb. | Jsonb supports indexing to search for the keys or key/ value pairs which is a great advantage for a bigger database jsonb documents. |
| 8 | In JSON, if more than one key exists for the given value, all the key/value pairs are preserved. | Jsonb does not preserve duplicate object keys. In duplicate, only the last key/value pair is preserved. |
| 9 | Unicode escapes are allowed in the JSON input function regardless of the data encoding. It only checks for syntactic errors. | The input function of jsonb is stricter than the JSON as it does not allow the Unicode escapes for non-ASCII characters if the database encoding of UTF8 is not set. |
Key Differences of PostgreSQL JSON vs JSONB
Some of the key differences between JSON and jsonb explaining the detailed differences between the two are given below:
1. One simple difference between JSON and jsonb data types is that JSON stores the exact copy of the data represented/ inputted in the JSON format to the user, whereas jsonb stores the data in the binary format, which means that the input data is first processed and then stored in the binary form.
2. When considering the ingesting speed and processing speed, it is evident that the process of ingesting data using JSONB would be somewhat slower. The reason behind this is that the data requires processing and encoding into a binary format before it can be stored. Still, the further processing of jsonb data is quite faster than JSON. So in case when there is a need only to ingest too much data, JSON data type would work great.
3. Besides the efficiency of data performance, Jsonb also provides the benefit of GIN (Generalised Inverted Index). It allows the testing of Containment, which checks whether one document is contained in another document with the help of @> operator. It returns the result as true or false. Another feature is the provision of an Existence Operator in jsonb which checks the existence of top-level keys in JSONB. JSONB provides a crucial feature that JSON lacks: efficient indexing, querying, and searching capabilities.
4. One of the important improvements of jsonb over JSON is that it allows the indexing of JSON data, which is quite helpful in retrieving speedy and correct results, especially in the case of aggregate functions when there are millions and trillions of data in the database.
5. jsonb does not store duplicate key/ value pairs, which can be good or bad depending on the user’s requirement. Unlike JSON, which only stores the last key/ value pairs, it only stores the key/value pairs.
6. One major drawback of using the jsonb in PostgreSQL is that PostgreSQL does not maintain the statistics while using the jsonb columns. PostgreSQL maintains comprehensive statistics for each table, including information about distinct values, most common values, NULL values, and histograms of distributions.Using the above data, the query planner in PostgreSQL makes the statistics of which plan will provide the best results. The lack of stored statistics for JSONB columns in PostgreSQL hinders effective planning and, ultimately, leads to suboptimal outcomes.
7. The lack of key name deduplication in JSONB storage leads to JSONB resulting in larger storage footprints compared to JSON, posing another problem with the JSON data type. Moreover, jsonb encoding of input text has a bit of overhead as it does not parse the JSON in order to retrieve a particular field. So the database stores the key/ value pair for each row, which increases the database size. If the key frequently appears in the jsonb blobs, one solution to the problem is to store the key as a column in the table.
Conclusion
Above description clearly explains what the JSON and jsonb data types are and how they work in PostgreSQL. While working with PostgreSQL, programmers must understand the difference between JSON and JSONB and utilize them appropriately for storing data based on their respective purposes. They should be able to distinguish between the two and make informed decisions on which one to use in a given scenario.
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