How to Count Jsonb Object Keys In Postgresql??

To count the keys in a JSONB object in PostgreSQL, you can use the jsonb_object_keys function along with the jsonb_each function.

For example, you can use the following query to count the keys in a JSONB object:

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SELECT COUNT(*)
FROM your_table,
jsonb_object_keys(your_jsonb_column) AS keys;

This query will return the total number of keys present in the JSONB object.

Keep in mind that this query will count the distinct keys in the JSONB object, so if you have duplicate keys, they will only be counted once.

How to count the number of keys in a JSONB object with nested arrays in PostgreSQL?

To count the number of keys in a JSONB object with nested arrays in PostgreSQL, you can use the jsonb_object_keys function along with the jsonb_each function to iterate over the keys and values of the JSONB object.

Here is an example query to count the number of keys in a JSONB object with nested arrays:

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SELECT COUNT(DISTINCT key)
FROM your_table,
     jsonb_each(your_jsonb_column) obj,
     jsonb_object_keys(obj.value) key;

Replace your_table with the name of your table and your_jsonb_column with the name of the column containing the JSONB object. This query will count the number of unique keys in the JSONB object, including keys in nested arrays.

Alternatively, you can also use the jsonb_each_text function instead of jsonb_each and jsonb_object_keys to directly extract key-value pairs and count the number of keys like this:

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SELECT COUNT(DISTINCT key)
FROM your_table,
     jsonb_each_text(your_jsonb_column);

Both of these queries will give you the count of keys in the JSONB object including nested arrays in PostgreSQL.

What is the most common key in a JSONB object in PostgreSQL?

There is no specific "most common key" in a JSONB object in PostgreSQL as it largely depends on how the data is structured and what kind of information is being stored in the JSONB object. Keys in a JSONB object can vary greatly depending on the nature of the data being stored, so there is no one key that is universally the most common.

What is the relationship between the number of keys and the size of a JSONB object in PostgreSQL?

In PostgreSQL, the size of a JSONB object is influenced by the number of keys and the size of the values associated with those keys. Generally, the more keys and larger values you have in a JSONB object, the larger the size of the object will be.

However, the size relationship may not be linear since JSONB is a compressed binary format that efficiently stores and indexes JSON data. This means that the actual size of a JSONB object may not directly correlate to the number of keys or the size of the values.

On the other hand, indexing and querying the data within the JSONB object can also impact the performance and size of the object. Creating indexes on specific keys within the JSONB object can improve query performance but may also increase the overall size of the object.

In summary, while the number of keys and size of values can influence the size of a JSONB object in PostgreSQL, the actual relationship may vary depending on the data and how it is stored and queried.