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Introduction Expression Index is an extremely powerful feature of PostgreSQL, which can be used for any data type (such as text, numbers, time, arrays and more) as long as the result of the expression returns a Deterministic value You can use Expression Index for all index types ( B-Tree , Hash , GIN , GiST and more) as long as the expression you write in the CREATE INDEX command returns a data type that the Index type supports for processing The nature of Expression Index is that instead of indexing on the original column value, Postgres precomputes the result of the function or expression as soon as you INSERT/UPDATE and saves the result directly into the Index file Characteristics After creating an Expression Index, when using a query, you must write it exactly like the expression in the Index, otherwise the index will not work Every time a row of data is modified, Postgres must run that function or expression to get the result to create the Index. Therefore, avoid using function...

Introduction In this article, we will continue exploring GIN Index with the JsonB data type. JsonB, short for JSON Binary, is a data type developed from the JSON data type and supported by PostgreSQL since version 9.2. The key difference between JSON and JsonB lies in how they are stored. JsonB supports binary storage and resolves the limitations of the JSON data type by optimizing the insert process and supporting indexing. Creating an Index When creating an index for a JsonB column, Postgres supports two strategies as follows: jsonb_ops : This is the default strategy that flattens the JSON to extract independent paths, keys and values to create Entries. For example, if you have a JSON like this: { "shop" : "ShopA" , "products" : [ { "product_name" : "mouse" , "price" : 50 } , { "product_name" : "keyboard" , "price" : 100 } ] } It will create a GIN Index as follows, n...

Introduction In this article, we will continue to explore how to use GIN Index with the text data type First, please note that GIN Index only works with multi-valued data types, meaning fields containing multiple values, so you can easily create an index with the array type However, if you create a similar index with the text type, an error will be reported because text is only a single-valued type, containing only one content string, so you must pass an additional function that defines how to split the text value into items in an array before the index can be created If you remember, when using GIN Index with a text array, you will encounter limitations regarding partial search and must enter the exact word to search for it to work, now you can solve that problem by using text combined with two functions, to_tsvector and pg_trgm Full-Text Search This method uses the to_tsvector function and its index creation process will be as follows Tokenization & Normalization Split the text...